Subaru IMPREZA 2004 Service Manual
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Subaru IMPREZA 2004 Service Manual

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Table of Contents

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Download this manual See also: Owner's Manual, Quick Reference Manual
2004 IMPREZA SERVICE MANUAL
ENGINE SECTION 1
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
FUJI HEAVY INDUSTRIES LTD.
QUICK REFERENCE INDEX
FUEL INJECTION (FUEL SYSTEMS)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES)
INTAKE (INDUCTION)
MECHANICAL
EXHAUST
COOLING
LUBRICATION
SPEED CONTROL SYSTEMS
IGNITION
STARTING/CHARGING SYSTEMS
ENGINE (DIAGNOSTICS)
FUEL INJECTION (FUEL SYSTEMS)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES)
INTAKE (INDUCTION)
MECHANICAL
EXHAUST
COOLING
FU(H4SO)
EC(H4SO)
IN(H4SO)
ME(H4SO)
EX(H4SO)
CO(H4SO)
LU(H4SO)
SP(H4SO)
IG(H4SO)
SC(H4SO)
EN(H4SO)(diag)
FU(H4SOw/oOBD)
EC(H4SOw/oOBD)
IN(H4SOw/oOBD)
ME(H4SOw/oOBD)
EX(H4SOw/oOBD)
CO(H4SOw/oOBD)
G1870GE2

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Summary of Contents for Subaru IMPREZA 2004

  • Page 1 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 2 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...

  • Page 3: Table Of Contents

    FUEL INJECTION (FUEL SYSTEMS) FU(H4SO) Page General Description ..................2 Throttle Body.....................15 Intake Manifold..................16 Engine Coolant Temperature Sensor............27 Crankshaft Position Sensor...............28 Camshaft Position Sensor.................29 Knock Sensor....................30 Throttle Position Sensor................31 Manifold Absolute Pressure Sensor............33 Intake Air Temperature Sensor ..............34 Idle Air Control Solenoid Valve ..............35 EGR Valve ....................36 Air Assist Injector Solenoid Valve .............37 Fuel Injector ....................38...

  • Page 4: General Description

    General Description FUEL INJECTION (FUEL SYSTEMS) 1. General Description A: SPECIFICATIONS Item Specification 50 2 (13.2 US gal, 11.0 Imp gal) Capacity Fuel tank Location Under rear seat Type Impeller Shutoff discharge pressure 370 — 677 kPa (3.77 — 6.9 kg/cm , 53.6 —...
  • Page 5 General Description FUEL INJECTION (FUEL SYSTEMS) B: COMPONENT 1. INTAKE MANIFOLD • 1.6 L MODEL (19) (22) (24) (19) (11) (10) (15) (21) (20) (14) (23) (18) (21) (17) (12) (17) (13) (16) (18) (18) (17) FU-02184 FU(H4SO)-3...
  • Page 6 General Description FUEL INJECTION (FUEL SYSTEMS) Intake manifold gasket RH (12) Intake manifold gasket LH (23) Accelerator cable bracket Fuel injector pipe (13) Fuel pipe protector LH (24) EGR valve Fuel injector (14) Plug cord holder LH O-ring (15) Fuel pipe protector RH Tightening torque: N·m (kgf-m, ft-lb) O-ring (16)
  • Page 7 General Description FUEL INJECTION (FUEL SYSTEMS) • 2.0 L MODEL (19) (21) (23) (19) (15) (10) (20) (11) (22) (14) (18) (17) (20) (12) (17) (13) (16) (18) (18) (17) FU-00954 FU(H4SO)-5...
  • Page 8 General Description FUEL INJECTION (FUEL SYSTEMS) Intake manifold gasket RH (11) Intake manifold (21) Plug cord holder RH Fuel injector pipe (12) Intake manifold gasket LH (22) Accelerator cable bracket Fuel injector (13) Fuel pipe protector LH (23) EGR valve O-ring (14) Plug cord holder LH...
  • Page 9 General Description FUEL INJECTION (FUEL SYSTEMS) 2. AIR INTAKE SYSTEM FU-00955 Gasket Throttle body Tightening torque: N·m (kgf-m, ft-lb) Throttle position sensor Intake air temperature sensor T1: 1.6 (0.16, 1.2) Idle air control solenoid valve Grommet T2: 22 (2.2, 15.9) Manifold absolute pressure sensor Air cleaner case FU(H4SO)-7...
  • Page 10 General Description FUEL INJECTION (FUEL SYSTEMS) 3. CRANKSHAFT POSITION, CAMSHAFT POSITION AND KNOCK SENSORS FU-00414 Crankshaft position sensor Camshaft position sensor support Tightening torque: N·m (kgf-m, ft-lb) Knock sensor T1: 6.4 (0.65, 4.7) Camshaft position sensor T2: 24 (2.4, 17.4) FU(H4SO)-8...
  • Page 11 General Description FUEL INJECTION (FUEL SYSTEMS) 4. FUEL TANK (25) (16) (10) (11) (11) (11) (14) (13) (24) (24) (12) (11) (11) (15) (11) (17) (19) (18) (20) (11) (21) (11) (22) (18) (19) (11) (23) FU-00908 FU(H4SO)-9...
  • Page 12 General Description FUEL INJECTION (FUEL SYSTEMS) Heat shield cover (11) Clip (21) Fuel pipe ASSY Fuel tank band (12) Evaporation hose B (22) Fuel return hose B Protector RH (13) Joint pipe (23) Evaporation hose E Fuel tank (14) Evaporation hose C (24) Evaporation hose F Fuel pump gasket...

  • Page 13: Fuel Line

    General Description FUEL INJECTION (FUEL SYSTEMS) 5. FUEL LINE (19) (18) (17) (24) (20) (16) (25) (15) (24) (22) (13) (21) (23) (14) (12) (1) (1) (10) (10) (11) FU-00516 FU(H4SO)-11...
  • Page 14 General Description FUEL INJECTION (FUEL SYSTEMS) Clip (11) Fuel pipe ASSY (21) Two-way valve drain hose A Fuel delivery hose A (12) Grommet (22) Connector Fuel filter bracket (13) Canister hose A (23) Two-way valve drain hose B Fuel filter holder (14) Canister (24)
  • Page 15 General Description FUEL INJECTION (FUEL SYSTEMS) 6. FUEL FILLER PIPE (11) (10) (12) FU-00956 Fuel filler pipe ASSY Air vent pipe (11) Filler cap tether Evaporation hose holder Air vent pipe holder (12) Filler pipe protector Clip Filler pipe packing Clamp Filler ring Tightening torque: N·m (kgf-m, ft-lb)
  • Page 16 TOOL NUMBER DESCRIPTION REMARKS 24082AA230 CARTRIDGE Troubleshooting for electrical system. ST24082AA230 22771AA030 SUBARU SELECT Troubleshooting for electrical systems. MONITOR KIT • English: 22771AA030 (Without printer) • German: 22771AA070 (Without printer) • French: 22771AA080 (Without printer) • Spanish: 22771AA090 (Without printer) ST22771AA030...

  • Page 17: Throttle Body

    Throttle Body FUEL INJECTION (FUEL SYSTEMS) 2. Throttle Body 6) Disconnect the air by-pass hose from throttle body. (1.6 L model) A: REMOVAL 1) Disconnect the ground cable from battery. FU-00957 7) Disconnect the engine coolant hoses (A) from FU-00009 throttle body.

  • Page 18: Intake Manifold

    Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 3. Intake Manifold NOTE: Do not disconnect the power steering hose. A: REMOVAL 1) Release the fuel pressure. <Ref. to FU(H4SO)- 50, RELEASING OF FUEL PRESSURE, OPERA- TION, Fuel.> 2) Open the fuel flap lid, and then remove the fuel filler cap.
  • Page 19 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) (7) Place the power steering pump on the right 12) Remove the air cleaner case stay RH and en- side wheel apron. gine harness bracket, and then disconnect the en- gine harness connectors from the bulkhead harness connectors.
  • Page 20 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 16) Disconnect the connector from the oil pressure 19) Disconnect the fuel hoses from fuel pipes. switch. WARNING: • Do not spill fuel. • Catch fuel from hoses in a container or cloth. FU-00146 17) Disconnect the connector from the camshaft position sensor.
  • Page 21 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 2) Connect the fuel hoses. 5) Connect the connector to the oil pressure switch. FU-00259 FU-00146 6) Connect the connector to the crankshaft position (A) Fuel delivery hose sensor. (B) Return hose (C) Evaporation hose 3) Connect the EGR pipe to intake manifold.
  • Page 22 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 9) Install the air cleaner case stay RH and engine (1) Install the reservoir tank to bracket. harness bracket, and connect the engine harness connectors to bulkhead connectors. FU-00020 (2) Connect the connector to the power steering FU-00258 pump switch.
  • Page 23 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) (5) Install the front side V-belt. <Ref. to C: DISASSEMBLY ME(H4SO)-43, INSTALLATION, V-belt.> 1) Disconnect the engine ground terminal from in- (6) Install the resonator chamber. <Ref. to take manifold. IN(H4SO)-7, INSTALLATION, Resonator Chamber.> 15) Connect the accelerator cable (A).
  • Page 24 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 8) Remove the fuel pipe protector RH. 13) Remove the bolt which installs the fuel injector pipe on the intake manifold as shown in the figure. FU-00267 FU-00959 9) Disconnect the connectors from fuel injectors. •...
  • Page 25 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) • 2.0 L MODEL 17) Loosen the clamp which holds the fuel injector pipe LH to fuel hose, and then remove the pipe from fuel hose. FU-00170 15) Remove the fuel injectors. FU-00171 (1) Remove the fuel injector securing clip. 18) Loosen the clamp which holds the fuel injector pipe RH to fuel hose, and then remove the pipe from fuel hose.
  • Page 26 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) Tightening torque: NOTE: 5.0 N·m (0.51 kgf-m, 3.7 ft-lb) Replace the O-rings with new ones. FU-00518 FU-01112 3) Connect the fuel injector pipe RH to fuel hose, (A) O-ring and then tighten the clamp screw. (B) Fuel injector NOTE: Do not forget to install the fuel injector securing clip.
  • Page 27 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) • RH SIDE 10) Hold the engine harness by harness bands (A) and bolts (B). FU-00960 FU-00888 • LH SIDE 11) Connect the connector to fuel injector. FU-00961 FU-00268 8) Tighten the two bolts which install the fuel pipes on intake manifold.
  • Page 28 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 14) Install the purge control solenoid valve. <Ref. to EC(H4SO)-7, INSTALLATION, Purge Control Solenoid Valve.> 15) Connect the pressure regulator vacuum hose to intake manifold. FU-00265 16) Install the air assist injector solenoid valve. (1.6 L model) <Ref.

  • Page 29: Engine Coolant Temperature Sensor

    Engine Coolant Temperature Sensor FUEL INJECTION (FUEL SYSTEMS) 4. Engine Coolant Temperature Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the air intake duct and air cleaner case. <Ref. to IN(H4SO)-6, REMOVAL, Air Intake Duct.> and <Ref.

  • Page 30: Crankshaft Position Sensor

    Crankshaft Position Sensor FUEL INJECTION (FUEL SYSTEMS) 5. Crankshaft Position Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the bolt which installs the crankshaft position sensor to cylinder block. FU-00056 3) Remove the crankshaft position sensor, and then disconnect the connector from it.

  • Page 31: Camshaft Position Sensor

    Camshaft Position Sensor FUEL INJECTION (FUEL SYSTEMS) 6. Camshaft Position Sensor 5) Remove the camshaft position sensor and cam- shaft position sensor support as a unit. A: REMOVAL 6) Remove the camshaft position sensor itself. 1) Disconnect the ground cable from battery. FU-00179 FU-00009 B: INSTALLATION...

  • Page 32: Knock Sensor

    Knock Sensor FUEL INJECTION (FUEL SYSTEMS) 7. Knock Sensor • The extraction area of the knock sensor cord must be positioned at a 60° angle relative to engine A: REMOVAL rear. 1) Disconnect the ground cable from battery. FU-00413 FU-00009 (A) Front side 2) Remove the air cleaner case.

  • Page 33: Throttle Position Sensor

    Throttle Position Sensor FUEL INJECTION (FUEL SYSTEMS) 8. Throttle Position Sensor C: ADJUSTMENT 1) Turn the ignition switch to OFF. A: REMOVAL 2) Loosen the throttle position sensor holding 1) Disconnect the ground cable from battery. screws. FU-00009 FU-00291 2) Disconnect the connector from the throttle posi- 3) When using voltage meter;...
  • Page 34 FU-00293 (4) Connect the Subaru Select Monitor to the data link connector. ME-00325 5) Turn the ignition switch to ON, and the Subaru Select Monitor switch to ON. 6) Select the {2. Each System Check} in «Main Menu». 7) Select the {Engine Control System} in «Selec- tion Menu».

  • Page 35: Manifold Absolute Pressure Sensor

    Manifold Absolute Pressure Sensor FUEL INJECTION (FUEL SYSTEMS) 9. Manifold Absolute Pressure • Replace the O-ring with a new one. Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00296 FU-00009 2) Disconnect the connector from manifold abso- lute pressure sensor. FU-00294 3) Remove the manifold absolute pressure sensor.

  • Page 36: Intake Air Temperature Sensor

    Intake Air Temperature Sensor FUEL INJECTION (FUEL SYSTEMS) 10.Intake Air Temperature Sen- A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector from the intake air temperature sensor. 3) Remove the intake air temperature sensor from the air cleaner case.

  • Page 37: Idle Air Control Solenoid Valve

    Idle Air Control Solenoid Valve FUEL INJECTION (FUEL SYSTEMS) 11.Idle Air Control Solenoid Valve A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector from the idle air con- trol solenoid valve. FU-00298 3) Remove the idle air control solenoid valve from throttle body.

  • Page 38: Egr Valve

    EGR Valve FUEL INJECTION (FUEL SYSTEMS) 12.EGR Valve A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector from EGR valve. FU-00521 3) Remove the EGR valve from intake manifold. FU-00211 B: INSTALLATION Install in the reverse order of removal. NOTE: For tightening torque, refer to “COMPONENT”.

  • Page 39: Engine Section

    EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 40 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 41 FUEL INJECTION (FUEL SYSTEMS) FU(H4SO) Page General Description ..................2 Throttle Body.....................15 Intake Manifold..................16 Engine Coolant Temperature Sensor............27 Crankshaft Position Sensor...............28 Camshaft Position Sensor.................29 Knock Sensor....................30 Throttle Position Sensor................31 Manifold Absolute Pressure Sensor............33 Intake Air Temperature Sensor ..............34 Idle Air Control Solenoid Valve ..............35 EGR Valve ....................36 Air Assist Injector Solenoid Valve .............37 Fuel Injector ....................38...

  • Page 42: Air Assist Injector Solenoid Valve

    Air Assist Injector Solenoid Valve FUEL INJECTION (FUEL SYSTEMS) 13.Air Assist Injector Solenoid Valve A: REMOVAL NOTE: Air assist injector solenoid valve is equipped in 1.6 L model only. 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector (A) from the air assist injector solenoid valve, and then disconnect the air by-pass hoses (B).

  • Page 43: Fuel Injector

    Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 14.Fuel Injector (3) Remove the bolts which install the power steering pump to bracket. A: REMOVAL 1. RH SIDE 1) Release the fuel pressure. <Ref. to FU(H4SO)-50, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Open the fuel flap lid, and remove the fuel filler cap.
  • Page 44 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 7) Remove the fuel pipe protector RH. (1) Remove the fuel injector securing clip. FU-00267 FU-00305 8) Disconnect the connector from fuel injector. (2) Remove the fuel injector while lifting up the fuel injector pipe. FU-00303 FU-00306 9) Remove the bolts which hold the fuel injector...
  • Page 45 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 4) Remove the two bolts which install the washer 9) Remove the spark plug cords from spark plugs tank on body. (#2 and #4 cylinders). FU-00190 FU-00307 5) Disconnect the connector from the front window 10) Remove the fuel pipe protector LH.
  • Page 46 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) • 1.6 L MODEL B: INSTALLATION 1. RH SIDE Install in the reverse order of removal. NOTE: Replace O-rings with new ones. FU-00962 • 2.0 L MODEL FU-01112 (A) O-ring (B) Fuel injector Tightening torque: 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) FU-00170 14) Remove the fuel injector from intake manifold.
  • Page 47 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) Tightening torque: • 1.6 L MODEL 19 N·m (1.9 kgf-m, 13.7 ft-lb) FU-00962 FU-00267 • 2.0 L MODEL Tightening torque: 33 N·m (3.4 kgf-m, 24.3 ft-lb) FU-00170 Tightening torque: IN-00044 19 N·m (1.9 kgf-m, 13.7 ft-lb) 2.

  • Page 48: Front Oxygen (A/F) Sensor

    Front Oxygen (A/F) Sensor FUEL INJECTION (FUEL SYSTEMS) 15.Front Oxygen (A/F) Sensor Anti-seize compound: SS-30 by JET LUBE A: REMOVAL CAUTION: 1) Disconnect the ground cable from battery. Never apply anti-seize compound to protector of the front oxygen (A/F) sensor. FU-00009 2) Disconnect the connector from engine hanger, FU-00196...
  • Page 49 Front Oxygen (A/F) Sensor FUEL INJECTION (FUEL SYSTEMS) 5) Connect the battery ground cable to battery. FU-00009 FU(H4SO)-44...

  • Page 50: Rear Oxygen Sensor

    Rear Oxygen Sensor FUEL INJECTION (FUEL SYSTEMS) 16.Rear Oxygen Sensor CAUTION: Never apply anti-seize compound to protector A: REMOVAL of the rear oxygen sensor. 1) Disconnect the ground cable from battery. Anti-seize compound: SS-30 by JET LUBE FU-00009 2) Lift-up the vehicle. FU-00199 3) Disconnect the connector from the rear oxygen 2) Install the rear oxygen sensor.
  • Page 51 Rear Oxygen Sensor FUEL INJECTION (FUEL SYSTEMS) 5) Connect the battery ground cable to battery. FU-00009 FU(H4SO)-46...

  • Page 52: Engine Control Module (Ecm)

    Engine Control Module (ECM) FUEL INJECTION (FUEL SYSTEMS) 17.Engine Control Module (ECM) A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the lower inner trim of passenger side. <Ref. to EI-47, REMOVAL, Lower Inner Trim.> 3) Detach the floor mat of front passenger seat. 4) Remove the protect cover.

  • Page 53: Main Relay

    Main Relay FUEL INJECTION (FUEL SYSTEMS) 18.Main Relay A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the passenger’s side front side sill cov- 3) Remove the bolt which holds the main bracket on body. 4) Disconnect the connectors from main relay. FU-00317 B: INSTALLATION Install in the reverse order of removal.

  • Page 54: Fuel Pump Relay

    Fuel Pump Relay FUEL INJECTION (FUEL SYSTEMS) 19.Fuel Pump Relay A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the passenger’s side front side sill cov- 3) Remove the bolt which holds the fuel pump relay bracket on body. 4) Disconnect the connector from fuel pump.

  • Page 55: Fuel

    Fuel FUEL INJECTION (FUEL SYSTEMS) 20.Fuel 5) Drain fuel from the fuel tank. Set a container under the vehicle, and then remove A: OPERATION the drain plug from fuel tank. 1. RELEASING OF FUEL PRESSURE WARNING: • Place “NO FIRE” signs near working area. •...

  • Page 56: Fuel Tank

    Fuel Tank FUEL INJECTION (FUEL SYSTEMS) 21.Fuel Tank 9) Loosen the clamp, and then disconnect the fuel filler hose and air vent hose from the fuel filler pipe. A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel. 1) Set the vehicle on a lift.
  • Page 57 Fuel Tank FUEL INJECTION (FUEL SYSTEMS) 6) Tighten the band mounting bolts. WARNING: A helper is required to perform this work. Tightening torque: 33 N·m (3.4 kgf-m, 24.3 ft-lb) FU-00411 FU-00411 3) Connect the two-way valve hose (A) to two-way valve, and then connect the canister hose (B) to 7) Install the rear crossmember.

  • Page 58: Fuel Filler Pipe

    Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 22.Fuel Filler Pipe 9) Drain fuel from the fuel tank. Set a container un- der the vehicle, and then remove the drain plug A: REMOVAL from fuel tank. WARNING: • Place “NO FIRE” signs near working area. •...
  • Page 59 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 13) Disconnect the air vent hose from fuel filler 18) Remove the air vent pipe together with clip pipe. from body. FU-00099 FU-00102 14) Remove the bolts which hold the fuel filler pipe B: INSTALLATION bracket on body.
  • Page 60 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 5) Connect the air vent hose to the fuel filler pipe. Tightening torque: 7.4 N·m (0.75 kgf-m, 5.4 ft-lb) FU-00099 FU-00100 6) Insert the fuel filler hose (A) approx. 35 to 40 mm (1.38 to 1.57 in) over lower end of fuel filler pipe, 9) Hold the evaporation hoses onto clip of fuel filler and then tighten the clamp.
  • Page 61 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 14) Connect the connector to fuel pump relay. FU-00262 15) Connect the battery ground cable to battery. FU-00009 FU(H4SO)-56...

  • Page 62: Fuel Pump

    Fuel Pump FUEL INJECTION (FUEL SYSTEMS) 23.Fuel Pump 8) Remove the access hole lid. A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel. NOTE: Fuel pump assembly consists of fuel pump and fuel level sensor.
  • Page 63 Fuel Pump FUEL INJECTION (FUEL SYSTEMS) B: INSTALLATION Install in the reverse order of removal. Do the fol- lowing: NOTE: Replace the gasket with a new one. (1) Ensure the sealing portion is free from fuel or foreign particles before installation. (2) Tighten the nuts to specified torque in alpha- betical sequence as shown in the figure.

  • Page 64: Fuel Level Sensor

    Fuel Level Sensor FUEL INJECTION (FUEL SYSTEMS) 24.Fuel Level Sensor A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel. NOTE: Fuel level sensor is built in the fuel pump assembly. 1) Remove the fuel pump assembly. <Ref. to FU(H4SO)-57, REMOVAL, Fuel Pump.>...

  • Page 65: Fuel Filter

    Fuel Filter FUEL INJECTION (FUEL SYSTEMS) 25.Fuel Filter A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel. 1) Release the fuel pressure. <Ref. to FU(H4SO)- 50, RELEASING OF FUEL PRESSURE, OPERA- TION, Fuel.>...

  • Page 66: Fuel Cut Valve

    Fuel Cut Valve FUEL INJECTION (FUEL SYSTEMS) 26.Fuel Cut Valve A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel. 1) Remove the fuel tank. <Ref. to FU(H4SO)-51, REMOVAL, Fuel Tank.> 2) Move the clip and disconnect the evaporation hose from fuel cut valve.

  • Page 67: Fuel Damper Valve

    Fuel Damper Valve FUEL INJECTION (FUEL SYSTEMS) 27.Fuel Damper Valve A: REMOVAL 1) Release the fuel pressure. <Ref. to FU(H4SO)- 50, RELEASING OF FUEL PRESSURE, OPERA- TION, Fuel.> 2) Remove the fuel damper valve from the fuel re- turn line. FU-00121 B: INSTALLATION Install in the reverse order of removal.

  • Page 68: Fuel Delivery, Return And Evaporation Lines

    Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) 28.Fuel Delivery, Return and Evaporation Lines A: REMOVAL 1) Set the vehicle on a lift. 2) Release the fuel pressure. <Ref. to FU(H4SO)-50, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 3) Open the fuel filler flap lid, and then remove the fuel filler cap. 4) Remove the floor mat.
  • Page 69 Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) (2) Hold the connector (A), and then push the NOTE: retainer (B) down. At this time, two clicking sounds are heard. (3) Pull out the connector (A) from retainer (B). ( A ) ( B ) ( C )
  • Page 70 Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) 2: 2.5 ± ± ± ± 1.5 mm (0.098 ± ± ± ± 0.059 in) L: 22.5 ± ± ± ± 2.5 mm (0.886 ± ± ± ± 0.098 in) ( 1 ) ( 2 ) ( 3 )

  • Page 71: Fuel System Trouble In General

    Fuel System Trouble in General FUEL INJECTION (FUEL SYSTEMS) 29.Fuel System Trouble in General A: INSPECTION Trouble and possible cause Corrective action 1. Insufficient fuel supply to the injector Fuel pump will not operate. Inspect connections, especially ground, and tighten ❍...
  • Page 72 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 73 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 74 EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) EC(H4SO) Page General Description ..................2 Front Catalytic Converter ................3 Rear Catalytic Converter................4 EGR Valve ....................5 Canister.......................6 Purge Control Solenoid Valve ..............7 Two-way Valve....................8...

  • Page 75: General Description

    General Description EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 1. General Description A: CAUTION • Wear working clothing, including a cap, protec- tive goggles, and protective shoes during opera- tion. • Remove contamination including dirt and corro- sion before removal, installation or disassembly. •...

  • Page 76: Front Catalytic Converter

    Front Catalytic Converter EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 2. Front Catalytic Converter A: REMOVAL The front and rear catalytic converter and center exhaust pipe are integrated into one unit. There- fore, the removal procedures are the same as those for center exhaust pipe. <Ref.

  • Page 77: Rear Catalytic Converter

    Rear Catalytic Converter EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 3. Rear Catalytic Converter A: REMOVAL The front and rear catalytic converter and center exhaust pipe are integrated into one unit. There- fore, the removal procedures are the same as those for center exhaust pipe. <Ref.

  • Page 78: Egr Valve

    EGR Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 4. EGR Valve A: PROCEDURE For EGR valve removal and installation proce- dures, refer to FU section. <Ref. to FU(H4SO)-36, EGR Valve.> EC(H4SO)-5...

  • Page 79: Canister

    Canister EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 5. Canister A: REMOVAL 1) Lift-up the vehicle. 2) Loosen the two clamps which hold the two can- ister hoses, and then disconnect the three evapo- ration hoses from canister. EC-00012 3) Remove the canister from body. EC-00013 B: INSTALLATION Install in the reverse order of removal.

  • Page 80: Purge Control Solenoid Valve

    Purge Control Solenoid Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 6. Purge Control Solenoid Valve NOTE: Connect the evaporation hoses as shown in the fig- A: REMOVAL ure. 1) Disconnect the ground cable from battery. EC-00015 FU-00009 (A) To fuel pipe 2) Disconnect the connector and hoses from the purge control solenoid valve, and then remove the (B) To intake manifold...

  • Page 81: Two-Way Valve

    Two-way Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 7. Two-way Valve A: REMOVAL 1) Lift-up the vehicle. 2) Remove the canister from body. <Ref. to EC(H4SO)-6, REMOVAL, Canister.> 3) Remove the two-way valve with bracket as a sin- gle unit from body. EC-00016 4) Remove the two-way valve from bracket.
  • Page 82 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 83 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 84 INTAKE (INDUCTION) IN(H4SO) Page General Description ..................2 Air Cleaner Element ..................4 Air Cleaner Case..................5 Air Intake Duct.....................6 Resonator Chamber..................7...

  • Page 85: General Description

    General Description INTAKE (INDUCTION) 1. General Description A: COMPONENT (21) (21) (11) (11) (20) (19) (20) (13) (19) (11) (14) (12) (10) (16) (18) (17) (15) IN-00178 IN(H4SO)-2...
  • Page 86 General Description INTAKE (INDUCTION) Spacer (11) Clip (21) Clip Bush (12) Air cleaner element Resonator chamber (13) Air cleaner case B Tightening torque: N·m (kgf-m, ft-lb) Cushion (14) Stay LH (MT model) T1: 33 (3.4, 24.6) Air intake duct A (1.6 L and 2.0 L) (15) Stay LH (AT model) T2: 6.5 (0.66, 4.8)

  • Page 87: Air Cleaner Element

    Air Cleaner Element INTAKE (INDUCTION) 2. Air Cleaner Element A: REMOVAL 1) Remove the air intake duct from air cleaner case. 2) Remove the bolt (A) which secures the air clean- er case to stay. 3) Remove the clip (B) above the air cleaner case. IN-00039 4) Remove the air cleaner element.

  • Page 88: Air Cleaner Case

    Air Cleaner Case INTAKE (INDUCTION) 3. Air Cleaner Case A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector (A) of intake air tem- perature sensor. 3) Remove the bolt (B) which installs the air cleaner case to the stay.

  • Page 89: Air Intake Duct

    Air Intake Duct INTAKE (INDUCTION) 4. Air Intake Duct A: REMOVAL 1) Remove the bolt (A) which installs the air intake duct A on front side of body. 2) Remove the clip (B) which connects the air in- take duct A to resonator chamber. 3) Remove the air intake duct A.

  • Page 90: Resonator Chamber

    Resonator Chamber INTAKE (INDUCTION) 5. Resonator Chamber A: REMOVAL 1) Remove the air intake duct. <Ref. to IN(H4SO)- 6, REMOVAL, Air Intake Duct.> 2) Remove the resonator chamber. IN-00044 B: INSTALLATION Install in the reverse order of removal. NOTE: Refer to “COMPONENT” for tightening torque. <Ref.
  • Page 91 Resonator Chamber INTAKE (INDUCTION) IN(H4SO)-8...
  • Page 92 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 93 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 94 MECHANICAL ME(H4SO) Page General Description ..................2 Compression .....................26 Idle Speed ....................27 Ignition Timing...................28 Intake Manifold Vacuum................29 Engine Oil Pressure ..................30 Fuel Pressure....................31 Valve Clearance..................32 Engine Assembly ..................34 Engine Mounting ..................41 Preparation for Overhaul................42 V-belt......................43 Crankshaft Pulley ..................45 Timing Belt Cover..................47 Timing Belt Assembly................48 Camshaft Sprocket..................53 Crankshaft Sprocket..................55...

  • Page 95: General Description

    General Description MECHANICAL 1. General Description A: SPECIFICATIONS Model 1.6 L 2.0 L 2.5 L Horizontally opposed, liquid cooled, 4-cylinder, 4-stroke gasoline Type engine Valve arrangement Belt driven, single over-head camshaft, 4-valve/cylinder 87.9 × 65.8 99.5 × 79.0 Bore × Stroke 92 ×...
  • Page 96 General Description MECHANICAL Bend limit 0.025 mm (0.0010 in) 0.030 — 0.090 mm (0.0012 — 0.0035 in) Thrust clearance Limit 0.10 mm (0.0039 in) 39.378 — 39.478 mm (1.5503 — 1.5542 in) Intake Limit 39.278 mm (1.5464 in) 1.6 L 39.565 —...
  • Page 97 General Description MECHANICAL Surface warpage limit (mating with cylinder head) 0.05 mm (0.0020 in) Surface grinding limit 0.1 mm (0.004 in) Standard height 201.0 mm (7.91 in) 87.905 — 87.915 mm (3.4608 — 3.4612 in) 1.6 L 87.895 — 87.905 mm (3.4604 — 3.4608 in) 92.005 —...
  • Page 98 General Description MECHANICAL Bend twist per 100 mm (3.94 Limit 0.10 mm (0.0039 in) in) in length Connecting 0.070 — 0.330 mm (0.0028 — 0.0130 in) Side clearance Limit 0.4 mm (0.016 in) 0.010 — 0.038 mm (0.0004 — 0.0015 in) 1.6 L 2.0 L Limit...
  • Page 99 General Description MECHANICAL Bend limit 0.035 mm (0.0014 in) Out-of-roundness 0.020 mm (0.0008 in) or less Crank pin and crank journal Grinding limit 0.250 mm (0.0098 in) 47.984 — 48.000 mm (1.8891 — 1.8898 in) 0.03 mm (0.0012 in) 47.954 — 47.970 mm (1.8879 — 1.8886 in) 1.6 L 0.05 mm (0.0020 in) 47.934 —...
  • Page 100 General Description MECHANICAL 1.998 — 2.011 mm (0.0787 — 0.0792 in) 0.03 mm (0.0012 in) 2.017 — 2.020 mm (0.0794 — 0.0795 in) #1, #3 0.05 mm (0.0020 in) 2.027 — 2.030 mm (0.0798 — 0.0799 in) 0.25 mm (0.0098 in) 2.127 —...

  • Page 101: Timing Belt

    General Description MECHANICAL B: COMPONENT 1. TIMING BELT (12) (10) (13) (11) (15) (14) (16) ME-00376 Timing belt cover No. 2 (RH) (10) Belt idler No. 2 Tightening torque: N·m (kgf-m, ft-lb) Timing belt guide (MT model) (11) Camshaft sprocket No. 2 T1: 5 (0.5, 3.6) Crankshaft sprocket (12)
  • Page 102 General Description MECHANICAL 2. CYLINDER HEAD AND CAMSHAFT (10) (19) (14) (15) (16) (13) (10) (18) (17) (11) (19) (12) ME-00186 Rocker cover (RH) (11) Cylinder head (LH) Tightening torque: N·m (kgf-m, ft-lb) Intake valve rocker ASSY (12) Camshaft (LH) T1: <Ref.
  • Page 103 General Description MECHANICAL 3. VALVE ROCKER ASSEMBLY ME-00187 Intake valve rocker arm Rocker shaft support Tightening torque: N·m (kgf-m, ft-lb) Valve rocker nut Intake rocker shaft T1: 5 (0.5, 3.6) Valve rocker adjust screw Exhaust rocker shaft T2: 10 (1.0, 7.2) Spring Exhaust valve rocker arm T3: 25 (2.5, 18.1)
  • Page 104 General Description MECHANICAL 4. CYLINDER HEAD AND VALVE ASSEMBLY ME-00760 Exhaust valve Valve spring seat Retainer Intake valve Intake valve oil seal Retainer key Valve guide Valve spring Exhaust valve oil seal ME(H4SO)-11...
  • Page 105 General Description MECHANICAL 5. CYLINDER BLOCK (11) (10) (14) (10) (10) (10) (26) (15) (12) (17) (16) (22) (18) (24) (21) (23) (25) (13) (20) (19) FU-01016 Oil pressure switch (14) Baffle plate Tightening torque: N·m (kgf-m, ft-lb) Cylinder block (RH) (15) Oil filter connector T1: 5 (0.5, 3.6)
  • Page 106 General Description MECHANICAL 6. CRANKSHAFT AND PISTON (10) (11) (12) (14) (12) (13) (12) (11) (15) (18) (10) (9) (8) (17) (16) (17) (16) ME-00190 ME(H4SO)-13...
  • Page 107 General Description MECHANICAL Flywheel (MT model) Circlip (17) Crankshaft bearing #2, #4 Reinforcement (AT model) (10) Connecting rod bolt (18) Crankshaft bearing #5 Drive plate (AT model) (11) Connecting rod Top ring (12) Connecting rod bearing Tightening torque: N·m (kgf-m, ft-lb) Second ring (13) Connecting rod cap...
  • Page 108 General Description MECHANICAL 7. ENGINE MOUNTING ME-00413 Front cushion rubber Front engine mounting bracket Tightening torque: N·m (kgf-m, ft-lb) T1: 35 (3.6, 25.8) T2: 42 (4.3, 31.0) T3: 85 (8.7, 63) ME(H4SO)-15...
  • Page 109 General Description MECHANICAL C: CAUTION • Be careful not to let oil, grease or coolant contact the timing belt, clutch disc and flywheel. • Wear working clothing, including a cap, protec- • All removed parts, if to be reused, should be re- tive goggles and protective shoes during operation.
  • Page 110 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 22771AA030 SUBARU Troubleshooting for electrical systems. SELECT MONI- • English: 22771AA030 (Without printer) TOR KIT • German: 22771AA070 (Without printer) • French: 22771AA080 (Without printer) • Spanish: 22771AA090 (Without printer) ST22771AA030 498267800 CYLINDER •...
  • Page 111 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 498457100 ENGINE STAND Used with ENGINE STAND (499817000). ADAPTER LH ST-498457100 498497100 CRANKSHAFT Used for stopping rotation of flywheel when loos- STOPPER ening and tightening crankshaft pulley bolt, etc. ST-498497100 498547000 OIL FILTER •...
  • Page 112 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 498747000 PISTON GUIDE Used for installing piston in cylinder. (1.6 L model) ST-498747000 398744300 PISTON GUIDE Used for installing piston in cylinder. (2.0 L model) ST-398744300 498747300 PISTON GUIDE Used for installing piston in cylinder. (2.5 L model) ST-498747300 498857100...
  • Page 113 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499017100 PISTON PIN Used for installing piston pin, piston and connect- GUIDE ing rod. ST-499017100 499037100 CONNECTING Used for removing and installing connecting rod ROD BUSHING bushing. REMOVER & INSTALLER ST-499037100  499057000 Used for removing flywheel (Dual mass flywheel).
  • Page 114 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499587500 OIL SEAL • Used for installing camshaft oil seal. INSTALLER • Used with OIL SEAL GUIDE (499597000). ST-499587500 499587700 CAMSHAFT OIL Used for installing cylinder head plug. SEAL INSTALLER ST-499587700 499097700 PISTON PIN Used for removing piston pin.
  • Page 115 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS  499497000 Used for removing and installing camshaft cap. TORX PLUS ST-499497000 499587100 OIL SEAL Used for installing oil pump oil seal. INSTALLER ST-499587100 499597000 OIL SEAL GUIDE • Used for installing camshaft oil seal. •...
  • Page 116 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499718000 VALVE SPRING Used for removing and installing valve spring. REMOVER ST-499718000 499767200 VALVE GUIDE Used for removing valve guides. REMOVER ST-499767200 499767400 VALVE GUIDE Used for reaming valve guides. REAMER ST-499767400 499767700 VALVE GUIDE Used for installing valve guide.
  • Page 117 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499767800 VALVE GUIDE Used for installing valve guide. (Exhaust side) ADJUSTER ST-499767700 499817100 ENGINE STAND • Stand used for engine disassembly and assem- bly. • Used with ENGINE STAND ADAPTER RH (498457000) & LH (498457100). ST-499817100 499977400 CRANKSHAFT...
  • Page 118 General Description MECHANICAL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499987500 CRANKSHAFT Used for rotating crankshaft. SOCKET ST-499987500 499897200 PISTON CIR- Used for removing and installing piston pin circlip. CLIP PLIERS ST-499897200 2. GENERAL PURPOSE TOOLS TOOL NAME REMARKS Compression Gauge Used for measuring compression. Tachometer (Secondary pick-up type) Used for measuring idle speed.

  • Page 119: Compression

    Compression MECHANICAL 2. Compression A: INSPECTION CAUTION: After warming up, engine becomes very hot. Be careful not to burn yourself during measure- ment. 1) After warming up the engine, turn the ignition switch to OFF. 2) Make sure that the battery is fully charged. 3) Lower the fuel pressure.

  • Page 120: Idle Speed

    2) Warm up the engine. 3) Stop the engine, and then turn the ignition switch to OFF. ME-00193 4) When using the Subaru Select Monitor, refer to NOTE: the following. <Ref. to ME(H4SO)-16, SPECIAL • When using the OBD-II general scan tool, care- TOOLS, PREPARATION TOOL, General Descrip- fully read its operation manual.

  • Page 121: Ignition Timing

    Ignition Timing MECHANICAL 4. Ignition Timing A: INSPECTION CAUTION: After warming up, engine becomes very hot. Be careful not to burn yourself during measure- ment. 1) Warm up the engine. 2) To check the ignition timing, connect a timing light to #1 cylinder spark plug cord, and illuminate the timing mark with timing light.

  • Page 122: Intake Manifold Vacuum

    Intake Manifold Vacuum MECHANICAL 5. Intake Manifold Vacuum A: INSPECTION 1) Warm up the engine. 2) Disconnect the brake vacuum hose, and then install the vacuum gauge to hose fitting on manifold. 3) Keep the engine at idle speed, and then read the vacuum gauge indication. By observing the gauge needle movement, the internal condition of engine can be diagnosed as described below.

  • Page 123: Engine Oil Pressure

    Engine Oil Pressure MECHANICAL 6. Engine Oil Pressure CAUTION: • If the oil pressure is out of specification, A: INSPECTION check the oil pump, oil filter and lubrication 1) Disconnect the ground cable from battery. line. <Ref. to LU(H4SO)-21, INSPECTION, En- gine Lubrication System Trouble in General.>...

  • Page 124: Fuel Pressure

    Fuel Pressure MECHANICAL 7. Fuel Pressure NOTE: The fuel pressure gauge registers 10 to 20 kPa (0.1 A: INSPECTION to 0.2 kg/cm , 1 to 3 psi) higher than standard val- ues during high-altitude operations. WARNING: Before removing the fuel pressure gauge, lower the fuel pressure.

  • Page 125: Valve Clearance

    Valve Clearance MECHANICAL 8. Valve Clearance NOTE: When arrow mark (A) on the camshaft sprocket A: INSPECTION (LH) comes exactly to the top, #1 cylinder piston is brought to the top dead center of compression NOTE: stroke. Inspection and adjustment of the valve clearance should be performed while engine is cold.
  • Page 126 Valve Clearance MECHANICAL • To set each cylinder piston to its top dead center Valve clearance: on compression stroke in the following sequence: Intake; 0.20 ± ± ± ± 0.02 mm (0.0079 ± ± ± ± 0.0008 in) #3, #2 and #4 cylinder, turn the crankshaft pulley clockwise by every 180°...

  • Page 127: Engine Assembly

    Engine Assembly MECHANICAL 9. Engine Assembly • AT MODEL A: REMOVAL 1) Set the vehicle on a lift. 2) Open the front hood fully, and then support with the hood stay. 3) Using the refrigerant recovery system, dis- charge refrigerant. <Ref. to AC-21, OPERATION, Refrigerant Recovery Procedure.>...
  • Page 128 Engine Assembly MECHANICAL (4) Engine harness connectors 13) Disconnect the following hoses. (1) Brake booster vacuum hose FU-00826 FU-00879 (5) Generator connector, terminal and A/C compressor connector (2) Heater inlet outlet hose ( B ) ( A ) ME-00208 ME-00330 14) Remove the power steering pump from brack- (A) Generator connector and terminal (B) A/C compressor connector...
  • Page 129 Engine Assembly MECHANICAL (4) Remove the bolts which install the power 17) Remove the nuts which install the front cushion steering pump bracket. rubber onto front crossmember. FU-00139 ME-00211 18) Separate the torque converter clutch from drive (5) Remove the power steering tank from bracket by pulling it upward.
  • Page 130 Engine Assembly MECHANICAL • Catch fuel from the hose into container. (2) Remove the bolts which hold the upper side of transmission to engine. ( A) (B ) FU-00149 ME-00216 21) Support the engine with a lifting device and 24) Install the ST to torque converter clutch case. wire ropes.
  • Page 131 Engine Assembly MECHANICAL 2) Install the engine onto transmission. Tightening torque: (1) Position the engine in engine compartment T1: 50 N·m (5.1 kgf-m, 37 ft-lb) and align it with transmission. T2: 58 N·m (5.9 kgf-m, 43 ft-lb) NOTE: Be careful not to damage the adjacent parts or body panels with crank pulley, oil level gauge, etc.
  • Page 132 Engine Assembly MECHANICAL 10) Install the power steering pump on bracket. (5) Install the front side V-belt, and adjust it. <Ref. to ME(H4SO)-43, FRONT SIDE BELT, IN- (1) Install the power steering tank on bracket. STALLATION, V-belt.> (6) Install the resonator chamber. Tightening torque: 33 N·m (3.4 kgf-m, 24.6 ft-lb) FU-00020...
  • Page 133 Engine Assembly MECHANICAL 14) Connect the following hoses. (1) Fuel delivery hose, return hose and evapo- ration hose (2) Heater inlet and outlet hoses (3) Brake booster vacuum hose 15) Connect the following connectors. (1) Engine ground cables Tightening torque: 14 N·m (1.4 kgf-m, 10.1 ft-lb) (2) Engine harness connectors (3) Generator connector and terminal...

  • Page 134: Engine Mounting

    Engine Mounting MECHANICAL 10.Engine Mounting A: REMOVAL 1) Remove engine assembly. <Ref. ME(H4SO)-34, REMOVAL, Engine Assembly.> 2) Remove the engine mounting from engine as- sembly. B: INSTALLATION Install in the reverse order of removal. Tightening torque: Engine mounting; 35 N·m (3.6 kgf-m, 25.8 ft-lb) C: INSPECTION Make sure there are no cracks or other damage.

  • Page 135: Preparation For Overhaul

    Preparation for Overhaul MECHANICAL 11.Preparation for Overhaul A: PROCEDURE 1) After removing the engine from body, secure it in the ST shown below. ST1 498457000 ENGINE STAND ADAPTER ST2 498457100 ENGINE STAND ADAPTER ST3 499817100 ENGINE STAND ME-00221 2) In this section the procedures described under each index are all connected and stated in order.

  • Page 136: V-Belt

    V-belt MECHANICAL 12.V-belt 4) Remove the belt tensioner. A: REMOVAL 1. FRONT SIDE BELT NOTE: Perform the following procedures 1) to 4) with the engine installed to body. 1) Remove the V-belt cover. ME-00225 B: INSTALLATION NOTE: Wipe off any oil or water on the belt and pulley. 1.
  • Page 137 V-belt MECHANICAL 3) Tighten the lock nut (A). Belt tension (without belt tension gauge) Tightening torque: Lock nut (A): When installing new parts: 22.6 N·m (2.3 kgf-m, 16.6 ft-lb) 7 — 9 mm (0.276 — 0.354 in) At inspection: 9 — 11 mm (0.354 — 0.433 in) When installing new parts: 7.5 —...
  • Page 138 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 139 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 140 MECHANICAL ME(H4SO) Page General Description ..................2 Compression .....................26 Idle Speed ....................27 Ignition Timing...................28 Intake Manifold Vacuum................29 Engine Oil Pressure ..................30 Fuel Pressure....................31 Valve Clearance..................32 Engine Assembly ..................34 Engine Mounting ..................41 Preparation for Overhaul................42 V-belt......................43 Crankshaft Pulley ..................45 Timing Belt Cover..................47 Timing Belt Assembly................48 Camshaft Sprocket..................53 Crankshaft Sprocket..................55...

  • Page 141: Crankshaft Pulley

    Crankshaft Pulley MECHANICAL 13.Crankshaft Pulley 3) Confirm that the tightening angle of crankshaft pulley bolt is 45 degrees or more. If the tightening A: REMOVAL angle of crankshaft pulley bolt is less than 45 de- grees, conduct the following procedures. 1) Remove the V-belt.
  • Page 142 Crankshaft Pulley MECHANICAL Tightening torque: 177 N·m (18.0 kgf-m, 130.2 ft-lb) ME-00227 3) Confirm that the tightening angle of crankshaft pulley bolt is 65 degrees or more. If the tightening angle of crankshaft pulley bolt is less than 65 de- grees, conduct the following procedures.

  • Page 143: Timing Belt Cover

    Timing Belt Cover MECHANICAL 14.Timing Belt Cover A: REMOVAL 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- MOVAL, V-belt.> 2) Remove crankshaft pulley. <Ref. ME(H4SO)-45, REMOVAL, Crankshaft Pulley.> 3) Remove the timing belt cover (LH). 4) Remove the front timing belt cover. ME-00229 (A) Timing belt cover (LH) (B) Front timing belt cover...

  • Page 144: Timing Belt Assembly

    Timing Belt Assembly MECHANICAL 15.Timing Belt Assembly A: REMOVAL 1. TIMING BELT 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- MOVAL, V-belt.> 2) Remove crankshaft pulley. <Ref. ME(H4SO)-45, REMOVAL, Crankshaft Pulley.> 3) Remove the timing belt cover. <Ref. to ME(H4SO)-47, REMOVAL, Timing Belt Cover.> 4) Remove the timing belt guide.
  • Page 145 Timing Belt Assembly MECHANICAL 7) Remove the belt idler No. 2. B: INSTALLATION 1. AUTOMATIC BELT TENSION ADJUST- ER ASSEMBLY AND BELT IDLER 1) Preparation for installation of automatic belt ten- sion adjuster assembly; CAUTION: • Always use a vertical type pressing tool to move the adjuster rod down.
  • Page 146 Timing Belt Assembly MECHANICAL Tightening torque: ST2 499207400 CAMSHAFT SPROCKET WRENCH 39 N·m (4.0 kgf-m, 28.9 ft-lb) ME-00243 ME-00241 (2) While aligning alignment marks (B) on the 3) Install the belt idler (No. 1). timing belt with marks (A) on sprockets, position Tightening torque: the timing belt properly.
  • Page 147 Timing Belt Assembly MECHANICAL 5) After ensuring that the marks on timing belt and Tightening torque: camshaft sprockets are aligned, remove the stop- 10 N·m (1.0 kgf-m, 7.2 ft-lb) per pin from belt tension adjuster. ME-00247 ME-00245 7) Install the timing belt cover. <Ref. to ME(H4SO)- 6) Install the timing belt guide.
  • Page 148 Timing Belt Assembly MECHANICAL 3) If the adjuster rod is not stiff and moves freely 2) Check the belt outer contacting surfaces of idler when applying 294 N (30 kgf, 66 lb), check it using pulley for abnormal wear and scratches. the following procedures: 3) Check the belt idler for grease leakage.

  • Page 149: Camshaft Sprocket

    Camshaft Sprocket MECHANICAL 16.Camshaft Sprocket Tightening torque: 78 N·m (8.0 kgf-m, 57.9 ft-lb) A: REMOVAL NOTE: Do not confuse the right and left side camshaft 1. REMOVAL sprockets during installation. The camshaft sprock- 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- et No.
  • Page 150 Camshaft Sprocket MECHANICAL 2) Make sure there is no free play between sprock- et and key. 3) Check the camshaft sprocket notch for sensor for damage and contamination of foreign matter. ME(H4SO)-54...

  • Page 151: Crankshaft Sprocket

    Crankshaft Sprocket MECHANICAL 17.Crankshaft Sprocket 2) Make sure there is no free play between sprock- et and key. A: REMOVAL 3) Check the crankshaft sprocket notch for sensor 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- for damage and contamination of foreign matter. MOVAL, V-belt.>...

  • Page 152: Valve Rocker Assembly

    Valve Rocker Assembly MECHANICAL 18.Valve Rocker Assembly (3) Tighten the bolts (a) through (d) to specified torque. A: REMOVAL Tightening torque: 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- 25 N·m (2.5 kgf-m, 18.1 ft-lb) MOVAL, V-belt.> 2) Remove crankshaft pulley.
  • Page 153 Valve Rocker Assembly MECHANICAL 3) Install the valve rocker shaft securing bolts. E: INSPECTION 1. VALVE ROCKER ARM AND ROCKER SHAFT 1) Measure the inside diameter of valve rocker arm and outside diameter of valve rocker shaft, and de- termine the difference between the two (= oil clear- ance).

  • Page 154: Camshaft

    Camshaft MECHANICAL 19.Camshaft 13) Remove the camshaft cap. (1) Remove the bolts (a) through (b) in alpha- A: REMOVAL betical sequence. 1) Remove the V-belt. <Ref. to ME(H4SO)-43, IN- STALLATION, V-belt.> 2) Remove crankshaft pulley. <Ref. ME(H4SO)-45, REMOVAL, Crankshaft Pulley.> ( a ) 3) Remove the timing belt cover.
  • Page 155 Camshaft MECHANICAL 16) Remove the plug from rear side of camshaft. (3) Install the valve rocker assembly. CAUTION: • Do not remove the oil seal unless necessary. • Do not scratch the journal surface when re- moving oil seal. B: INSTALLATION 1) Apply a coat of engine oil to the camshaft jour- nals, and then install the camshaft.
  • Page 156 Camshaft MECHANICAL Tightening torque: 8) Install the camshaft position sensor support. (LH side only) 10 N·m (1.0 kgf-m, 7.2 ft-lb) 9) Install the tensioner bracket. ( q ) ( o ) Tightening torque: 25 N·m (2.5 kgf-m, 18.1 ft-lb) ( u ) ( s ) ( t ) ( v )
  • Page 157 Camshaft MECHANICAL C: INSPECTION Model Item Unit: mm (in) 39.485 — 39.585 1. CAMSHAFT (1.5545 — 1.5585) Intake 1) Measure the bend, and repair or replace if nec- Limit 39.385 (1.5506) 2.5 L essary. 39.257 — 39.357 (1.5455 — 1.5495) Exhaust Limit: Limit...

  • Page 158: Cylinder Head Assembly

    Cylinder Head Assembly MECHANICAL 20.Cylinder Head Assembly 13) Remove the cylinder head gasket. CAUTION: A: REMOVAL Do not scratch the mating surface of cylinder 1) Remove the V-belt. <Ref. to ME(H4SO)-43, RE- head and cylinder block. MOVAL, V-belt.> 14) Similarly, remove the right side cylinder head. 2) Remove crankshaft pulley.
  • Page 159 Cylinder Head Assembly MECHANICAL 6) Install the intake manifold. <Ref. to FU(H4SO)- 2) Set the ST on valve spring. Compress the valve 18, INSTALLATION, Intake Manifold.> or <Ref. to spring, and then remove the valve spring retainer FU(H4SOw/oOBD)-18, INSTALLATION, Intake key.
  • Page 160 Cylinder Head Assembly MECHANICAL 1) Installation of valve spring and valve Free length 54.30 mm (2.1378 in) (1) Place the cylinder head on ST. Squareness 2.5°, 2.4 mm (0.094 in) ST 498267800 CYLINDER HEAD TABLE 214 — 246 N (2) Coat the stem of each valve with engine oil (22 —...
  • Page 161 Cylinder Head Assembly MECHANICAL Color of spring part: 2. VALVE SEAT Intake [Silver] Inspect the intake and exhaust valve seats, and Exhaust [Silver] then correct the contact surfaces with valve seat cutter if they are defective or when valve guides are replaced.
  • Page 162 Cylinder Head Assembly MECHANICAL Limit (3) Turn the cylinder head upside down and place ST as shown in the figure. 0.15 mm (0.0059 in) Intake side: ST 499767700 VALVE GUIDE ADJUSTER Exhaust side: ST 499767800 VALVE GUIDE ADJUSTER Valve guide ME-00288 ME-00291 (A) Valve guide...
  • Page 163 Cylinder Head Assembly MECHANICAL Valve guide protrusion: L Intake Intake 20.0 — 20.5 mm (0.787 — 0.807 in) Standard 1.0 mm (0.039 in) Exhaust Limit 0.6 mm (0.024 in) 16.5 — 17.0 mm (0.650 — 0.669 in) Exhaust Standard 1.2 mm (0.047 in) Limit 0.6 mm (0.024 in) Valve overall length: Intake...

  • Page 164: Cylinder Block

    Cylinder Block MECHANICAL 21.Cylinder Block 12) Remove the bolts (a) and (c) to remove cylinder head. A: REMOVAL NOTE: Before conducting this procedure, drain the engine oil completely if applicable. 1) Remove intake manifold. <Ref. FU(H4SO)-16, REMOVAL, Intake Manifold.> or <Ref.
  • Page 165 Cylinder Block MECHANICAL ST1 498497100 CRANKSHAFT STOPPER (3) Insert a oil pan cutter blade between cylin-  der block-to-oil pan clearance, and then remove ST2 499057000 TORX PLUS the oil pan. NOTE: Do not use a screwdriver or similar tool in place of oil pan cutter.
  • Page 166 Cylinder Block MECHANICAL ME-00139 Service hole plug Circlip Service hole cover Gasket Piston pin O-ring 27) Remove the service hole cover and service ST 499897200 PISTON CIRCLIP PLIER hole plugs using hexagon wrench [14 mm (0.55 in)]. ME-00141 29) Draw out the piston pin from #1 and #2 pistons ME-00140 using ST.
  • Page 167 Cylinder Block MECHANICAL NOTE: Be careful not to confuse the original combination of piston, piston pin and cylinder. ME-00142 30) Similarly remove the piston pins from #3 and #4 pistons. 31) Remove the bolts which connect the cylinder block on the side of #2 and #4 cylinders. 32) Back off the bolts which connect the cylinder block on the side of #1 and #3 cylinders two or three turns.
  • Page 168 Cylinder Block MECHANICAL NOTE: When separating the cylinder block, do not allow the connecting rod to fall and damage the cylinder block. ME-00143 Cylinder block Crankshaft Piston Rear oil seal Crankshaft bearing 35) Remove the rear oil seal. 36) Remove the crankshaft together with connect- ing rod.
  • Page 169 Cylinder Block MECHANICAL B: INSTALLATION ME-00144 Crankshaft bearing Cylinder block Rear oil seal Crankshaft NOTE: NOTE: Remove oil in the mating surface of bearing and Do not allow fluid packing to jut into O-ring grooves, cylinder block before installation. Also apply a coat oil passages, bearing grooves, etc.
  • Page 170 Cylinder Block MECHANICAL Tightening torque: 7) Tighten the 8 mm and 6 mm cylinder block con- necting bolts in alphabetical sequence shown in the 15 N·m (1.5 kgf-m, 10.8 ft-lb) figure. Tightening torque: (A) — (G): 25 N·m (2.5 kgf-m, 18.1 ft-lb) (H): 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) ME-00398 4) Tighten the 10 mm cylinder block connecting...
  • Page 171 Cylinder Block MECHANICAL 11) Position the expander gap at (C) in the figure. • Ensure ring gaps are not within the piston skirt area. 14) Install the circlip. Install circlips in the piston holes located opposite service holes in cylinder block, when positioning all pistons in the corresponding cylinders.
  • Page 172 Cylinder Block MECHANICAL ME-00155 Piston Gasket Tightening torque: N·m (kgf-m, ft-lb) Piston pin Service hole plug T: 70 (7.0, 50.6) Circlip 15) Installing piston ST3 499017100 PISTON PIN GUIDE (1) Turn the cylinder block to face the #1 and #2 piston side upward.
  • Page 173 Cylinder Block MECHANICAL Fluid packing: (6) Install the service hole plug and gasket. Part No. 004403007 NOTE: THREE BOND 1215 or equivalent Use a new gasket. ME-00160 ME-00140 ME-00161 Piston Service hole plug Tightening torque: N·m (kgf-m, ft-lb) Piston pin Service hole cover T1: 6.4 (0.65, 4.7) Circlip...
  • Page 174 Cylinder Block MECHANICAL 17) Install the water pipe. 23) Install the flywheel or drive plate. To lock the crankshaft, use ST. ST 498497100 CRANKSHAFT STOPPER Tightening torque: 72 N·m (7.3 kgf-m, 52.8 ft-lb) • MT MODEL ME-00300 18) Install the baffle plate. Tightening torque: 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) 19) Install the oil strainer and O-ring.
  • Page 175 Cylinder Block MECHANICAL ST 499587100 OIL SEAL INSTALLER 26) Install the water pump and gasket. Tightening torque: First; 12 N·m (1.2 kgf-m, 8.7 ft-lb) Second; 12 N·m (1.2 kgf-m, 8.7 ft-lb) CAUTION: • Be sure to use a new gasket. •...
  • Page 176 Cylinder Block MECHANICAL 33) Install camshaft sprocket. <Ref. CAUTION: ME(H4SO)-53, INSTALLATION, Camshaft Ensure that the total “re-tightening angle” [in the former two steps], do not exceed 180° ° ° ° . Sprocket.> 34) Install the timing belt assembly. <Ref. to ME(H4SO)-49, INSTALLATION, Timing Belt As- sembly.>...
  • Page 177 Cylinder Block MECHANICAL D: ASSEMBLY ME-00392 Connecting rod bearing Second ring Tightening torque: N·m (kgf-m, ft-lb) Connecting rod Top ring T: 45 (4.6, 33) Connecting rod cap Circlip Oil ring Side mark 1) Apply oil to the surfaces of the connecting rod Warping limit: bearings.
  • Page 178 Cylinder Block MECHANICAL Standard diameter: Out-of-roundness: 1.6 L model Standard A: 87.905 — 87.915 mm (3.4608 — 3.4612 in) 0.010 mm (0.0004 in) B: 87.895 — 87.905 mm (3.4604 — 3.4608 in) Limit 2.0 L model 0.050 mm (0.0020 in) A: 92.005 —...
  • Page 179 Cylinder Block MECHANICAL Piston outer diameter: 6) Boring and honing 1.6 L model (1) If the value of taper, out-of-roundness, or cylinder-to-piston clearance measured exceeds Standard the specified limit or if there is any damage on A: 87.885 — 87.895 mm (3.4600 — 3.4604 the cylinder wall, reboring it to use an oversize piston.
  • Page 180 Cylinder Block MECHANICAL Standard clearance between piston pin and • Oil ring is composed of upper rail, expander hole in piston: and lower rail. Be careful of the rail direction Standard when installing oil ring to the piston. 0.004 — 0.008 mm (0.0002 — 0.0003 in) Limit 0.020 mm (0.0008 in) ME-00173...
  • Page 181 Cylinder Block MECHANICAL 3) Squarely place the piston ring and oil ring in cyl- 5. CONNECTING ROD inder, and then measure the piston ring gap with a 1) Replace the connecting rod, if the large or small thickness gauge. end thrust surface is damaged. 2) Check for bend or twist using a connecting rod Unit: mm (in) aligner.
  • Page 182 Cylinder Block MECHANICAL 4) Inspect the connecting rod bearing for scar, 2.5 L model peeling, seizure, melting, wear, etc. Standard 5) Measure the oil clearance on individual connect- 0.020 — 0.046 mm (0.0008 — 0.0018 in) ing rod bearings by means of plastigauge. If any oil Limit clearance is not within specification, replace the 0.05 mm (0.0020 in)
  • Page 183 Cylinder Block MECHANICAL 7) Replacement procedure is as follows. 3) Inspect the crank journal and crank pin for wear. If they are not within the specifications, replace the (1) Remove the bushing from connecting rod with ST and press. bearing with a suitable (undersize) one, and then replace or recondition the crankshaft as necessary.
  • Page 184 Cylinder Block MECHANICAL Unit: mm (in) Crank journal diameter Crank pin diameter #1, #3 #2, #4, #5 1.6 L 2.0 L 2.5 L Journal 59.992 — 60.008 59.992 — 60.008 47.984 — 48.000 51.984 — 52.000 51.984 — 52.000 O.D. (2.3619 —...

  • Page 185: Engine Trouble In General

    Engine Trouble in General MECHANICAL 22.Engine Trouble in General A: INSPECTION NOTE: “RANK” shown in the chart refer to the possibility of reason for the trouble in order (“Very often” to “Rarely”) A — Very often B — Sometimes C — Rarely TROUBLE PROBLEM PARTS, ETC.
  • Page 186 Engine Trouble in General MECHANICAL TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK 3) Initial combustion occurs. Engine control system <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Procedure.> or <Ref. to EN(H4SOw/oOBD)(diag)-2, Basic Diagnostic Procedure.> Intake system Defective intake manifold gasket Defective throttle body gasket Fuel line Defective fuel pump and relay Clogged fuel line...
  • Page 187 Engine Trouble in General MECHANICAL TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK 2. Rough idle and engine Engine control system <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Procedure.> or stall <Ref. to EN(H4SOw/oOBD)(diag)-2, Basic Diagnostic Procedure.> Intake system Loosened or cracked intake duct Loosened or cracked PCV hose Loosened or cracked vacuum hose Defective intake manifold gasket...
  • Page 188 Engine Trouble in General MECHANICAL TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK 3. Low output, hesitation and Engine control system <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Procedure.> or poor acceleration <Ref. to EN(H4SOw/oOBD)(diag)-2, Basic Diagnostic Procedure.> Intake system Loosened or cracked intake duct Loosened or cracked PCV hose Loosened or cracked vacuum hose Defective intake manifold gasket...
  • Page 189 Engine Trouble in General MECHANICAL TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK 5. Engine does not return to Engine control system <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Procedure.> or idle. <Ref. to EN(H4SOw/oOBD)(diag)-2, Basic Diagnostic Procedure.> Intake system Loosened or cracked vacuum hose Others Stuck or damaged throttle valve Accelerator cable out of adjustment...
  • Page 190 Engine Trouble in General MECHANICAL TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK 10. Excessive fuel consump- Engine control system <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Procedure.> or tion <Ref. to EN(H4SOw/oOBD)(diag)-2, Basic Diagnostic Procedure.> Intake system Dirty air cleaner element Belt Defective timing Compression Incorrect valve clearance...
  • Page 191 Engine Noise MECHANICAL 23.Engine Noise A: INSPECTION Type of sound Condition Possible cause • Valve mechanism is defective. • Incorrect valve clearance Sound increases as engine Regular clicking sound • Worn valve rocker speed increases. • Worn camshaft • Broken valve spring •...
  • Page 192 Engine Noise MECHANICAL ME(H4SO)-96...
  • Page 193 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 194 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 195 EXHAUST EX(H4SO) Page General Description ..................2 Front Exhaust Pipe..................6 Center Exhaust Pipe ...................9 Rear Exhaust Pipe ..................10 Muffler .......................12...

  • Page 196: General Description

    General Description EXHAUST 1. General Description A: COMPONENT 1. 1.6 L (16) (15) (13) (14) (16) (11) (10) (12) (16) (27) (26) (17) (28) (22) (18) (25) (24) (23) (31) (30) (19) (29) (21) (20) (31) EX-00123 EX(H4SO)-2...
  • Page 197 General Description EXHAUST Front exhaust pipe upper cover (15) Muffler (28) Rear catalytic converter upper Front exhaust pipe lower cover (16) Cushion rubber cover Clamp (17) Clamp (29) Rear catalytic converter lower Front exhaust pipe upper cover LH (18) Center exhaust pipe upper cover cover Front exhaust pipe lower cover LH (19)
  • Page 198 General Description EXHAUST 2. 2.0 L (16) (15) (13) (14) (16) (11) (10) (17) (16) (28) (27) (18) (29) (23) (19) (26) (25) (24) (12) (31) (20) (30) (22) (21) (12) EX-00124 EX(H4SO)-4...
  • Page 199 General Description EXHAUST Front exhaust pipe upper cover (16) Cushion rubber (29) Rear catalytic converter upper Front exhaust pipe lower cover (17) Rear exhaust pipe cover Clamp (18) Clamp (30) Rear catalytic converter lower cover Front exhaust pipe upper cover LH (19) Center exhaust pipe upper cover Front exhaust pipe lower cover LH...

  • Page 200: Front Exhaust Pipe

    Front Exhaust Pipe EXHAUST 2. Front Exhaust Pipe • 1.6 L A: REMOVAL 1) Disconnect the ground cable from battery. EX-00125 • 2.0 L FU-00009 2) Disconnect the front oxygen (A/F) sensor con- nector. EX-00031 6) Remove the under cover. 7) Remove the nuts which hold the front exhaust pipe onto cylinder heads.
  • Page 201 Front Exhaust Pipe EXHAUST 9) Remove the front and center exhaust pipe as- 4) Temporarily tighten the bolt which installs the sembly from vehicle. front and center exhaust pipe assembly to hanger bracket. CAUTION: • Be careful not to let the front and center ex- haust pipe assembly fall off when removing as it is quite heavy.
  • Page 202 Front Exhaust Pipe EXHAUST • 2.0 L 12) Connect the battery ground cable to battery. EX-00031 FU-00009 8) Tighten the bolt which holds the front and center C: INSPECTION exhaust pipe assembly to hanger bracket. 1) Make sure there are no exhaust leaks from con- nections and welds.

  • Page 203: Center Exhaust Pipe

    Center Exhaust Pipe EXHAUST 3. Center Exhaust Pipe A: REMOVAL After removing the center and front exhaust pipes as one unit, separate them. Refer to the procedure for removing the front exhaust pipe. <Ref. to EX(H4SO)-6, REMOVAL, Front Exhaust Pipe.> B: INSTALLATION Install the center exhaust pipe and front exhaust pipe as one unit.

  • Page 204: Rear Exhaust Pipe

    Rear Exhaust Pipe EXHAUST 4. Rear Exhaust Pipe 4) Remove the rear exhaust pipe bracket from cushion rubber. A: REMOVAL 1) Separate the rear exhaust pipe from center ex- haust pipe. CAUTION: Be careful, the exhaust pipe is hot. • 1.6 L EX-00126 B: INSTALLATION 1) Apply a coat of spray type lubricant to the mating...
  • Page 205 Rear Exhaust Pipe EXHAUST • 1.6 L EX-00125 • 2.0 L EX-00031 C: INSPECTION 1) Make sure there are no exhaust leaks from con- nections and welds. 2) Make sure there are no holes or rusting. 3) Make sure the cushion rubber is not worn or cracked.

  • Page 206: Muffler

    Muffler EXHAUST 5. Muffler 3) Make sure the cushion rubber is not worn or cracked. A: REMOVAL 1) Separate the muffler from rear exhaust pipe. CAUTION: Be careful, the exhaust pipe is hot. EX-00024 2) Apply a coat of spray type lubricant to the mating area of cushion rubbers in advance.
  • Page 207 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 208 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 209 COOLING CO(H4SO) Page General Description ..................2 Radiator Main Fan System................6 Radiator Sub Fan System ................9 Engine Coolant..................13 Water Pump ....................15 Thermostat ....................18 Radiator.....................19 Radiator Cap .....................22 Radiator Main Fan and Fan Motor ............23 Radiator Sub Fan and Fan Motor..............24 Reservoir Tank..................25 Engine Cooling System Trouble in General ..........26...

  • Page 210: General Description

    General Description COOLING 1. General Description A: SPECIFICATIONS Cooling system Electric fan + Forced engine coolant circulation system 1.6 L AT model: Approx. 7.3 (7.71, 6.42) 1.6 L MT model: Approx. 7.4 (7.82, 6.51) 2 (US qt, Imp qt) Total engine coolant capacity 2.0 L and 2.5 L AT model: Approx.
  • Page 211 General Description COOLING B: COMPONENT 1. WATER PUMP CO-00001 Water pump ASSY Gasket Tightening torque: N·m (kgf-m, ft-lb) Gasket Thermostat cover T1: First 12 (1.2, 8.7) Second 12 (1.2, 8.7) Heater by-pass hose Thermostat T2: 6.5 (0.66, 4.8) CO(H4SO)-3...
  • Page 212 General Description COOLING 2. RADIATOR AND RADIATOR FAN (12) (10) (15) (11) (13) (24) (16) (17) (16) (14) (18) (21) (16) (16) (16) (23) (19) (20) (16) (22) CO-00221 (1) Radiator lower cushion (12) Radiator sub fan motor (23) Radiator lower bracket (2) Radiator (13) Radiator main fan shroud (24) Radiator drain plug...
  • Page 213 General Description COOLING C: CAUTION • Be careful not to burn your hands, because each part in the vehicle is hot after running. • Wear working clothing, including a cap, protec- • Be sure to tighten fasteners including bolts and tive goggles, and protective shoes during opera- nuts to the specified torque.
  • Page 214 Radiator Main Fan System COOLING 2. Radiator Main Fan System A: WIRING DIAGRAM BATTERY SBF-1 IGNITION SWITCH SBF-4 No.17 No.18 AIR CONDITIONING AIR CONDITIONING RELAY HOLDER RELAY HOLDER MAIN RELAY RELAY MAIN FAN SUB FAN MOTOR MOTOR B225 WITH OBD MODEL : 14 WITUOUT OBD MODEL : 3 WITH OBD MODEL : 13 WITUOUT OBD MODEL : 12...

  • Page 215: Radiator Main Fan System

    Radiator Main Fan System COOLING B: INSPECTION DETECTING CONDITION: • Engine coolant temperature is above 96°C (205°F). • Vehicle speed is below 19 km/h (12 MPH). TROUBLE SYMPTOM: Radiator main fan does not rotate under the above conditions. Step Check CHECK POWER SUPPLY TO MAIN FAN MO- Is the voltage more than 10 V? Go to step 2.
  • Page 216 Radiator Main Fan System COOLING Step Check CHECK POWER SUPPLY TO A/C RELAY Is the voltage more than 10 V? Repair the open Repair the open HOLDER 20 A FUSE TERMINAL. circuit in harness circuit in harness Measure the voltage of harness between A/C between 20 A fuse between main fuse relay holder 20 A fuse terminal and chassis...
  • Page 217 Radiator Sub Fan System COOLING 3. Radiator Sub Fan System A: WIRING DIAGRAM BATTERY SBF-1 IGNITION SWITCH SBF-4 No.17 AIR CONDITIONING No.18 AIR CONDITIONING RELAY HOLDER RELAY HOLDER MAIN RELAY RELAY MAIN FAN SUB FAN MOTOR MOTOR B225 WITH OBD MODEL : 14 WITUOUT OBD MODEL : 3 WITH OBD MODEL : 13 WITUOUT OBD MODEL : 12...

  • Page 218: Radiator Sub Fan System

    Radiator Sub Fan System COOLING B: INSPECTION NOTE: System for A/C equipped models only. DETECTING CONDITION: Condition (1): • Engine coolant temperature is below 95°C (203°F). • A/C switch is turned ON. • Vehicle speed is below 19 km/h (12 MPH). Condition (2): •...
  • Page 219 Radiator Sub Fan System COOLING Step Check CHECK POWER SUPPLY TO SUB FAN RE- Is the voltage more than 10 V? Go to step 10. Go to step 9. LAY. 1)Turn the ignition switch to ON. 2)Measure the voltage between sub fan relay terminal and chassis ground.
  • Page 220 Radiator Sub Fan System COOLING Step Check CHECK POOR CONTACT. Is there poor contact in con- Repair the poor Verify the DTC. Check poor contact in connector between sub nector between sub fan motor contact connector. Repair the trouble fan and ECM. and ECM? cause.

  • Page 221: Engine Coolant

    Approx. 7.0 2 (7.4 US qt, 6.2 Imp qt) NOTE: The SUBARU Genuine Coolant containing anti- freeze and anti-rust agents is especially made for SUBARU engine, which has an aluminum crank- case. Always use SUBARU Genuine Coolant, since other coolant may cause corrosion. CO(H4SO)-13...
  • Page 222 The concentration and safe operating temperature necessary amount of coolant with an undiluted so- of the SUBARU coolant is shown in the diagram. lution of SUBARU genuine coolant (concentration Measuring the temperature and specific gravity of 50%).

  • Page 223: Water Pump

    Water Pump COOLING 5. Water Pump 7) Remove the belt cover No. 2 (LH). A: REMOVAL 1) Remove the radiator. <Ref. to CO(H4SO)-19, REMOVAL, Radiator.> 2) Remove the V-belts. <Ref. to ME(H4SO)-43, REMOVAL, V-belt.> 3) Remove the timing belt. <Ref. to ME(H4SO)-48, TIMING BELT, REMOV- AL, Timing Belt Assembly.>...
  • Page 224 Water Pump COOLING Tightening torque: Tightening torque: First: 78 N·m (8.0 kgf-m, 57.9 ft-lb) 12 N·m (1.2 kgf-m, 8.7 ft-lb) Second: 12 N·m (1.2 kgf-m, 8.7 ft-lb) CO-00018 6) Install the belt idler No. 2. Tightening torque: CO-00026 39 N·m (4.0 kgf-m, 28.9 ft-lb) 2) Connect the hose to water pump.
  • Page 225 Water Pump COOLING “Thrust” runout limit: 0.5 mm (0.020 in) CO-00028 4) Check the clearance between impeller and pump case. Clearance between impeller and pump case: Standard 0.5 — 0.7 mm (0.020 — 0.028 in) Limit 1.0 mm (0.039 in) CO-00029 5) After water pump installation, check the pulley shaft for engine coolant leaks.

  • Page 226: Thermostat

    Thermostat COOLING 6. Thermostat Tightening torque: 6.5 N·m (0.65 kgf-m, 4.7 ft-lb) A: REMOVAL 1) Set the vehicle on a lift. 2) Lift-up the vehicle. 3) Remove the under cover. 4) Drain the engine coolant completely. <Ref. to CO(H4SO)-13, DRAINING OF ENGINE COOL- ANT, REPLACEMENT, Engine Coolant.>...

  • Page 227: Radiator

    Radiator COOLING 7. Radiator 7) Disconnect the radiator outlet hose from water pump. A: REMOVAL 1) Set the vehicle on a lift. 2) Disconnect the ground cable from battery. CO-00076 8) Disconnect the ATF cooler hoses from ATF pipe. (AT model) FU-00009 Plug the openings in the hose and radiator with caps in order to prevent ATF from leaking.
  • Page 228 Radiator COOLING 14) Remove the radiator upper brackets. Tightening torque: 18 N·m (1.8 kgf-m, 13.0 ft-lb) CO-00090 CO-00090 15) Detach the power steering hose from clip on ra- diator. 4) Attach the power steering hose to radiator. CO-00037 CO-00037 16) Lift the radiator up and away from the vehicle. 5) Connect the radiator inlet hose.
  • Page 229 Radiator COOLING 11) Connect the radiator outlet hose. C: INSPECTION 1) Remove the radiator cap, top off radiator, and then attach the tester to radiator in place of cap. CO-00076 12) Connect the connectors to radiator main fan CO-00094 motor (A) and sub fan motor (B). 2) Apply a pressure of 157 kPa (1.6 kg/cm , 23 psi) to the radiator to check if:...

  • Page 230: Radiator Cap

    Radiator Cap COOLING 8. Radiator Cap A: INSPECTION 1) Attach the radiator cap to tester. CO-00044 2) Increase the pressure until tester gauge pointer stops. Radiator cap is functioning properly if it holds the service limit pressure for 5 to 6 seconds. Standard pressure: 93 —...

  • Page 231: Radiator Main Fan And Fan Motor

    Radiator Main Fan and Fan Motor COOLING 9. Radiator Main Fan and Fan B: INSTALLATION Install in the reverse order of removal. Motor NOTE: A: REMOVAL • If it is difficult to install the radiator main fan motor 1) Set the vehicle on a lift. assembly, first loosen the bolts which hold the radi- 2) Disconnect the ground cable from battery.

  • Page 232: Radiator Sub Fan And Fan Motor

    Radiator Sub Fan and Fan Motor COOLING 10.Radiator Sub Fan and Fan B: INSTALLATION Install in the reverse order of removal. Motor NOTE: A: REMOVAL Refer to COMPONENT for tightening torque. <Ref. 1) Set the vehicle on a lift. to CO(H4SO)-3, COMPONENT, General Descrip- 2) Disconnect the ground cable from battery.

  • Page 233: Reservoir Tank

    Reservoir Tank COOLING 11.Reservoir Tank A: REMOVAL 1) Disconnect the overflow hose from the radiator filler neck position. 2) Pressing the pawl (A), remove the reservoir tank by pulling in the direction indicated by the arrow. CO-00226 B: INSTALLATION Install in the reverse order of removal. C: INSPECTION Make sure the engine coolant level is between full and low.

  • Page 234: Engine Cooling System Trouble In General

    Engine Cooling System Trouble in General COOLING 12.Engine Cooling System Trouble in General A: INSPECTION Trouble Possible cause Corrective action Replenish the engine coolant, inspect for leakage, and a. Insufficient engine coolant repair. b. Loose timing belt Repair or replace the timing belt tensioner. c.
  • Page 235 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 236 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 237 LUBRICATION LU(H4SO) Page General Description ..................2 Oil Pressure System ...................7 Engine Oil....................9 Oil Pump ....................11 Oil Pan and Strainer..................15 Oil Pressure Switch...................19 Engine Oil Filter..................20 Engine Lubrication System Trouble in General.........21...

  • Page 238: General Description

    General Description LUBRICATION 1. General Description A: SPECIFICATIONS Lubrication method Forced lubrication Pump type Trochoid type Inner rotor Number of teeth Outer rotor Outer rotor diameter × thickness 78 × 7 mm (3.07 × 0.28 in) STANDARD 0.04 — 0.14 mm (0.0016 — 0.0055 in) Tip clearance between inner and outer rotor LIMIT 0.18 mm (0.0071 in)
  • Page 239 General Description LUBRICATION B: COMPONENT (13) (16) (15) (14) (12) (17) (11) (10) (18) (24) (19) (27) (20) (21) (22) (26) (25) (23) LU-00106 Plug (13) Oil pressure switch (25) Drain plug Gasket (14) Oil filler duct (26) Metal gasket Relief valve spring (15) O-ring...
  • Page 240 General Description LUBRICATION C: CAUTION • Wear working clothing, including a cap, protec- tive goggles, and protective shoes during opera- tion. • Remove contamination including dirt and corro- sion before removal, installation or disassembly. • Keep the disassembled parts in order and pro- tect them from dust or dirt.

  • Page 241: Special Tools

    General Description LUBRICATION D: PREPARATION TOOL 1. SPECIAL TOOLS ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499977400 CRANKSHAFT • Used for stopping rotation of crankshaft pulley PULLEY when loosening and tightening crankshaft pulley WRENCH bolt. • For 1.6 L and 2.0 L models. ST-499977400 499977100 CRANKSHAFT...
  • Page 242 General Description LUBRICATION ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 18332AA010 OIL FILTER • Used for removing and installing oil filter. WRENCH • For oil filter (Outer diameter: 65 mm (2.56 in)) ST18332AA010 499587100 OIL SEAL Used for installing oil pump oil seal. INSTALLER ST-499587100 LU(H4SO)-6...

  • Page 243: Oil Pressure System

    Oil Pressure System LUBRICATION 2. Oil Pressure System A: WIRING DIAGRAM BATTERY No.13 SBF-4 SBF-1 IGNITION SWITCH COMBINATION METER : 14 : 31 OIL PRESSURE SWITCH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5 6 7 8 9 10 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 9 10...
  • Page 244 Oil Pressure System LUBRICATION B: INSPECTION Step Check CHECK COMBINATION METER. Does the warning lights go on? Go to step 2. Repair or replace 1)Turn the ignition switch to ON. (engine OFF) the combination 2)Check other warning lights. meter. <Ref. to IDI-3, INSPEC- TION, Combina- tion Meter...

  • Page 245: Engine Oil

    Engine Oil LUBRICATION 3. Engine Oil NOTE: Prepare the container for draining of engine oil. A: INSPECTION 1) Park the vehicle on a level surface. 2) Remove the oil level gauge and wipe it clean. 3) Reinsert the level gauge all the way. Be sure that the level gauge is correctly inserted and in the proper orientation.
  • Page 246 API classification and SAE viscosity No. designat- ed by SUBARU. NOTE: If the vehicle is used in areas with very high temper-...

  • Page 247: Oil Pump

    Oil Pump LUBRICATION 4. Oil Pump ST 499977100 CRANKSHAFT PULLEY WRENCH (2.5 L model) A: REMOVAL 1) Disconnect the ground cable from battery. LU-00012 10) Remove the water pump. <Ref. to CO(H4SO)- FU-00009 15, REMOVAL, Water Pump.> 2) Lift-up the vehicle. 11) Remove the timing belt guide.
  • Page 248 Oil Pump LUBRICATION 3) Apply a coat of engine oil to the inside of oil seal. NOTE: If disassembling or inspecting the oil pump, loosen the plug of relief valve before removing the oil pump. LU-00018 4) Be careful not to scratch the oil seal when install- ing oil pump on cylinder block.
  • Page 249 Oil Pump LUBRICATION 3) Install the inner and outer rotors in their original CAUTION: positions. Before disassembling the oil pump, remove the 4) Install the oil relief valve and relief valve spring relief valve. and plug. NOTE: Use a new gasket. 5) Install the oil pump cover.
  • Page 250 Oil Pump LUBRICATION 2. CASE CLEARANCE 5. OIL PUMP CASE Measure the clearance between the outer rotor and Check the oil pump case for worn shaft hole, oil pump rotor housing. If clearance exceeds the clogged oil passage, worn rotor chamber, cracks, limit, replace the rotor.

  • Page 251: Oil Pan And Strainer

    Oil Pan and Strainer LUBRICATION 5. Oil Pan and Strainer 8) Support the engine with a lifting device and wire ropes. A: REMOVAL 1) Set the vehicle on a lift. 2) Remove the front wheels. 3) Disconnect the ground cable from battery. LU-00028 9) Lift-up the vehicle.
  • Page 252 Oil Pan and Strainer LUBRICATION 15) Insert the oil pan cutter blade between the cyl- Tightening torque: inder block to oil pan clearance. 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) CAUTION: Do not use a screwdriver or similar tool in place of oil pan cutter.
  • Page 253 Oil Pan and Strainer LUBRICATION Tightening torque: 10) Remove the lifting device and steel cables. 5 N·m (0.5 kgf-m, 3.6 ft-lb) LU-00028 LU-00031 11) Install the pitching stopper. 5) Lower the engine onto front crossmember. Tightening torque: 6) Tighten the nuts which install the front cushion T1: 50 N·m (5.1 kgf-m, 36.9 ft-lb) rubber onto front crossmember.
  • Page 254 Oil Pan and Strainer LUBRICATION 16) Connect the battery ground cable to battery. FU-00009 17) Fill engine oil. <Ref. to LU(H4SO)-9, INSPEC- TION, Engine Oil.> C: INSPECTION By visual check make sure the oil pan, oil strainer, oil strainer stay and baffle plate are not damaged. LU(H4SO)-18...

  • Page 255: Oil Pressure Switch

    Oil Pressure Switch LUBRICATION 6. Oil Pressure Switch Tightening torque: 25 N·m (2.5 kgf-m, 18.1 ft-lb) A: REMOVAL 1) Remove the generator from bracket. <Ref. to SC(H4SO)-13, REMOVAL, Generator.> 2) Disconnect the terminal from oil pressure switch. LU-00037 3) Connect the terminal of oil pressure switch. LU-00036 3) Remove the oil pressure switch.

  • Page 256: Engine Oil Filter

    Engine Oil Filter LUBRICATION 7. Engine Oil Filter A: REMOVAL 1) Lift up the vehicle. 2) Remove the under cover. 3) Remove the oil filter with ST. ST 498547000 OIL FILTER WRENCH (Outer diameter: 80 mm (3.15 in)) ST 18332AA000 OIL FILTER WRENCH (Outer diameter: 68 mm (2.68 in)) ST 18332AA010 OIL FILTER WRENCH (Outer diameter: 65 mm (2.56 in))

  • Page 257: Engine Lubrication System Trouble In General

    Engine Lubrication System Trouble in General LUBRICATION 8. Engine Lubrication System Trouble in General A: INSPECTION Before performing diagnostics, make sure the engine oil level is correct and no oil leakage exists. Trouble Possible cause Corrective action Cracked diaphragm or oil leakage within switch Replace.
  • Page 258 Engine Lubrication System Trouble in General LUBRICATION LU(H4SO)-22...
  • Page 259 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 260 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 261 SPEED CONTROL SYSTEMS SP(H4SO) Page General Description ..................2 Accelerator Pedal..................4 Accelerator Control Cable ................9...
  • Page 262 General Description SPEED CONTROL SYSTEMS 1. General Description A: SPECIFICATION Free play At pedal pad 0 — 4 mm (0 — 0.16 in) Accelerator pedal Stroke At pedal pad 52 — 57 mm (2.05 — 2.24 in) B: COMPONENT 1. LHD MODEL (13) (11) (10)
  • Page 263 General Description SPEED CONTROL SYSTEMS 2. RHD MODEL (11) (10) SP-00022 Accelerator bracket Spring pin (11) Kick-down switch (AT model) Stopper Accelerator spring Accelerator pedal lever Bushing Tightening torque: N·m (kgf-m, ft-lb) Accelerator pedal spring Clip T1: 12 (1.2, 9.0) Accelerator pedal (10) Accelerator stopper...
  • Page 264 Accelerator Pedal SPEED CONTROL SYSTEMS 2. Accelerator Pedal • RHD SOHC MODEL A: REMOVAL 1) Disconnect the ground cable from battery. 2) Remove the lock nut from accelerator cable bracket. 3) Separate the accelerator cable from bracket. 4) Remove the accelerator cable end from throttle cam.
  • Page 265 Accelerator Pedal SPEED CONTROL SYSTEMS • LHD MODEL 12) Disconnect the accelerator cable stopper (A) from bracket. SP-00018 SP-00010 • RHD MODEL 13) Separate the accelerator cable and bracket. B: INSTALLATION Install in the reverse order of removal. NOTE: • If the cable clamp is damaged, replace it with a new one.
  • Page 266 Accelerator Pedal SPEED CONTROL SYSTEMS • LHD MODEL • RHD MODEL SP-00024 SP-00025 (A) Accelerator bracket (A) Accelerator bracket (B) Stopper (B) Stopper (C) Bushing (C) Bushing (D) Clip (D) Clip (E) Accelerator spring (E) Accelerator spring (F) Accelerator pedal spring (F) Accelerator pedal spring (G) Accelerator pedal lever (G) Accelerator pedal lever...
  • Page 267 Accelerator Pedal SPEED CONTROL SYSTEMS Deflection of accelerator pedal: Stroke at pedal pad: A Service limit 52 — 57 mm (2.05 — 2.24 in) ±2.0 mm (±0.079 in) or less SP-00013 2. KICK-DOWN SWITCH If the kick-down switch does not operate properly (or if it does not stop at the specified position), re- place with a new one.
  • Page 268 Accelerator Pedal SPEED CONTROL SYSTEMS Kick-down switch tightening torque: 12 N·m (1.2 kgf-m, 9 ft-lb) SP-00028 (A) Kick down switch SP(H4SO)-8...
  • Page 269 Accelerator Control Cable SPEED CONTROL SYSTEMS 3. Accelerator Control Cable A: REMOVAL 1) Remove the accelerator pedal. <Ref. to SP(H4SO)-4, REMOVAL, Accelerator Pedal.> 2) Separate the accelerator cable and accelerator pedal. B: INSTALLATION 1) Install in the reverse order of removal. NOTE: •...
  • Page 270 Accelerator Control Cable SPEED CONTROL SYSTEMS SP(H4SO)-10...
  • Page 271 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 272 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 273 IGNITION IG(H4SO) Page General Description ..................2 Spark Plug....................5 Ignition Coil & Ignitor ASSY ................8 Spark Plug Cord..................10...

  • Page 274: General Description

    General Description IGNITION 1. General Description A: SPECIFICATIONS Item Designation 1.6 L CM12 — 100C Model 2.0 L FH0137 2.5 L 1.6 L HITACHI Manufacturer 2.0 L DIAMOND 2.5 L 0.7 Ω±10% Ignition coil & ignitor 1.6 L ASSY Primary coil resistance 2.0 L 0.73 Ω±10% 2.5 L...
  • Page 275 General Description IGNITION B: COMPONENT 1. 1.6 L MODEL IG-00016 (1) Spark plug (4) Spark plug cord (#2, #4) Tightening torque: N·m (kgf-m, ft-lb) (2) Spark plug cord (#1, #3) T1: 6.4 (0.65, 4.7) (3) Ignition coil & ignitor ASSY T2: 21 (2.1, 15.5) IG(H4SO)-3...
  • Page 276 General Description IGNITION 2. 2.0 L AND 2.5 L MODEL IG-00088 (1) Spark plug (4) Spark plug cord (#2, #4) Tightening torque: N·m (kgf-m, ft-lb) (2) Spark plug cord (#1, #3) T1: 6.4 (0.65, 4.7) (3) Ignition coil & ignitor ASSY T2: 21 (2.1, 15.5) C: CAUTION •...

  • Page 277: Spark Plug

    Spark Plug IGNITION 2. Spark Plug 4) Remove the spark plugs using spark plug sock- ets. A: REMOVAL CAUTION: All spark plugs installed on an engine, must be of the same heat range. Spark plug NGK: BKR6E* 1.6 L CHAMPION: RC8YC4** NGK: BKR6E-11** (Alternate) 2.0 L NGK: BKR6E*...
  • Page 278 Spark Plug IGNITION 5) Remove the spark plug cords by pulling the boot, C: INSPECTION not cord itself. Check the electrodes and inner and outer ceramic insulator of plugs, noting the type of deposits and the degree of electrode erosion. IG-00021 6) Remove the spark plugs with spark plug sock- IG-00023...
  • Page 279 Spark Plug IGNITION 3) Oil fouled: Spark plug gap: L Wet black deposits show excessive oil entrance With catalyst: into combustion chamber through worn rings and 1.0 — 1.1 mm (0.039 — 0.043 in) pistons or excessive clearance between valve Without catalyst: guides and stems.

  • Page 280: Ignition Coil & Ignitor Assy

    Ignition Coil & Ignitor ASSY IGNITION 3. Ignition Coil & Ignitor ASSY • 1.6 L MODEL A: REMOVAL 1) Disconnect the ground cable from battery. IG-00083 • 2.0 L and 2.5 L MODEL FU-00009 2) Disconnect the spark plug cords from ignition coil and ignitor ASSY.
  • Page 281 Ignition Coil & Ignitor ASSY IGNITION Specified resistance: (1.6 L model) [Secondary side] Between (A) and (B) 18.0 k Ω± Ω± 20% Ω± Ω± Between (C) and (D) 18.0 k Ω± Ω± Ω± 20% Ω± IG-00030 Specified resistance: (2.0 L and 2.5 L model) [Secondary side] Between (A) and (B) 12.8 k Ω±...

  • Page 282: Spark Plug Cord

    Spark Plug Cord IGNITION 4. Spark Plug Cord A: INSPECTION Check for: 1) Damage to cords, deformation, burning or rust formation of terminals 2) Resistance values of cords Resistance value: #1 cord: 6.1 — 10.5 k Ω Ω Ω Ω #2 cord: 8.0 —...
  • Page 283 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 284 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 285 STARTING/CHARGING SYSTEMS SC(H4SO) Page General Description ..................2 Starter ......................7 Generator ....................13 Battery.......................19...

  • Page 286: General Description

    General Description STARTING/CHARGING SYSTEMS 1. General Description A: SPECIFICATIONS 1. NON-TURBO MODEL Item Designation Type Reduction type Vehicle type 1.6 L AT 2.0 L AT, 2.5 L AT Model M000T30471 M000T30571 M000T20171 Manufacturer Mitsubishi Electric Voltage and output 12 V — 1.0 kW 12 V —...
  • Page 287 General Description STARTING/CHARGING SYSTEMS 2. TURBO MODEL Item Designation Type Reduction type Vehicle type Model 228000 — 9270 M001T20171 Manufacturer DENSO Mitsubishi Electric Voltage and output 12 V — 1.0 kW 12 V — 1.4 kW Direction of rotation Counterclockwise (when observed from pinion) Number of pinion teeth Voltage 11.5 V...
  • Page 288 General Description STARTING/CHARGING SYSTEMS B: COMPONENT 1. STARTER • EXCEPT FOR DOHC TURBO MT MODEL (10) (16) (12) (11) (14) (15) (13) SC-02009 Front bracket Internal gear ASSY (13) Brush holder ASSY Sleeve bearing Shaft ASSY (14) Sleeve bearing Lever set Gear ASSY (15) Rear cover...
  • Page 289 General Description STARTING/CHARGING SYSTEMS • DOHC TURBO MT MODEL (11) (10) (17) (16) (15) (14) (13) (12) SC-00168 Sleeve bearing Internal gear ASSY (13) Armature Front bracket Shaft ASSY (14) Brush holder ASSY Lever set Gear ASSY (15) Brush Magnet switch ASSY (10) Ball (16)
  • Page 290 General Description STARTING/CHARGING SYSTEMS 2. GENERATOR (12) (11) (10) SC-00144 Pulley Rotor Brush Front cover Bearing (10) Rectifier Ball bearing Stator coil (11) Rear cover Bearing retainer IC regulator with brush (12) Terminal C: CAUTION • Be careful not to burn your hands, because each part on the vehicle is hot after running.

  • Page 291: Starter

    Starter STARTING/CHARGING SYSTEMS 2. Starter 5) Disconnect the connector and terminal from starter. A: REMOVAL 1) Disconnect the ground cable from battery. SC-00006 (A) Terminal FU-00009 (B) Connector 2) Remove the air cleaner case. (Non-turbo model) <Ref. to IN(H4SO)-5, REMOVAL, Air Cleaner 6) Remove the starter from transmission.
  • Page 292 Starter STARTING/CHARGING SYSTEMS NOTE: NOTE: Be careful because the pinion gap adjustment Before removal of the yoke, put alignment marks washer may sometimes be used on the mounting on the yoke and front bracket. surface of switch assembly. SC-00171 SC-00169 (A) Front bracket (A) Switch ASSY (B) Yoke...
  • Page 293 Starter STARTING/CHARGING SYSTEMS 2. BRUSH HOLDER NOTE: Note the direction of the lever before removing. NOTE: Only the brush holder of turbo MT model starter can be disassembled. Slightly open the metal fitting while holding the in- sulating plate against the brush holder. Remove the insulating plate.
  • Page 294 Starter STARTING/CHARGING SYSTEMS Commutator run-out: 4) Armature short-circuit test Standard Check the armature for short-circuit by placing it on a growler tester. Hold an iron sheet against the ar- 0.05 mm (0.0020 in) mature core while slowly rotating armature. A Service limit short-circuited armature will cause the iron sheet to Less than 0.10 mm (0.0039 in)
  • Page 295 Starter STARTING/CHARGING SYSTEMS 4. BRUSH AND BRUSH HOLDER Terminal/Specified resistance: S — M/Less than 1 Ω Ω Ω Ω 1) Brush length S — Ground/Less than 1 Ω Ω Ω Ω Measure the brush length, and then replace if it is M —...
  • Page 296 Starter STARTING/CHARGING SYSTEMS 7. PERFORMANCE TEST 2) Load test Apply the specified braking torque to starter. The The starter should be submitted to performance condition is satisfactory if the current draw and tests whenever it has been overhauled, to assure starter speed are within the specifications.

  • Page 297: Generator

    Generator STARTING/CHARGING SYSTEMS 3. Generator 5) Remove the bolts which install generator onto bracket. A: REMOVAL 1) Disconnect the ground cable from battery. SC-00032 B: INSTALLATION FU-00009 Install in the reverse order of removal. 2) Disconnect the connector and terminal from Tightening torque: generator.
  • Page 298 Generator STARTING/CHARGING SYSTEMS 2) Heat portion (A) of rear cover to 50°C (122°F) CAUTION: with a heater drier. When holding the rotor with a vise, place alumi- num plates or wooden pieces on the vise jaws to prevent rotor from damage. ( A ) ( B ) SC-00079...
  • Page 299 Generator STARTING/CHARGING SYSTEMS 6) Remove the bearing from rotor using a bearing (2) Unsolder the connection between IC regula- puller. tor and rectifier to remove the IC regulator. SC-00046 SC-00085 7) Unsolder connection between rectifier and stator 9) Remove the brush as follows. coil to remove the stator coil.
  • Page 300 Generator STARTING/CHARGING SYSTEMS 10) Remove the rectifier as follows. CAUTION: (1) Remove the bolts which secure the rectifier. Be sure to remove the wire after reassembly. SC-00089 SC-00092 (2) Remove the cover of terminal B. (A) Wire 2) Install the ball bearing. (1) Set the ball bearing on the front cover, and then securely install an appropriate tool (such as a fit socket wrench) to the bearing outer race.
  • Page 301 Generator STARTING/CHARGING SYSTEMS 1) Checking positive diode If the resistance is not within the specified range, replace the rotor assembly. Check for continuity between the diode lead and positive side heat sink. The positive diode is in Specified resistance: good condition if resistance is 1 Ω or less only in the Approx.
  • Page 302 Generator STARTING/CHARGING SYSTEMS 2) Insulation test 2) Checking brush spring for proper pressure Inspect the stator coil for continuity between stator Using a spring pressure indicator, push the brush core and each end of lead wire. If resistance is 1 Ω into the brush holder until its tip protrudes 2 mm or less, the stator coil is grounded, and so replace (0.08 in).

  • Page 303: Battery

    Battery STARTING/CHARGING SYSTEMS 4. Battery 1. EXTERNAL PARTS: Check for the existence of dirt or cracks on battery A: REMOVAL case, top cover, vent plugs, and terminal posts. If 1) Disconnect the positive (+) cable after discon- necessary, clean with water and wipe with a dry necting the ground (−) cable of battery.
  • Page 304 Battery STARTING/CHARGING SYSTEMS • Be careful since the battery electrolyte over- flows while charging the battery. • Observe the instructions when handling bat- tery charger. • Before charging the battery on vehicle, dis- connect battery ground terminal to prevent damage of generator diodes or other electrical units.
  • Page 305 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 306 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 307 Engine Control Module (ECM) I/O Signal ..........23 Engine Condition Data ................26 Transmission Control Module (TCM) I/O Signal ........27 Data Link Connector .................28 OBD-II General Scan Tool ................29 Subaru Select Monitor................32 Read Diagnostic Trouble Code (DTC) ............39 Inspection Mode..................40 Drive Cycle....................45 Clear Memory Mode..................47 Compulsory Valve Operation Check Mode ..........48...

  • Page 308: Basic Diagnostic Procedure

    Select Monitor or OBD-II general scan tool Code (DTC).> Go function indicator switch to ON. to step 4. light illuminates, 4)Read the DTC on the Subaru Select Monitor perform diagnos- or OBD-II general scan tool. tics of malfunction indicator light cir- cuit or combination meter.
  • Page 309 Basic Diagnostic Procedure ENGINE (DIAGNOSTICS) 2. AUTOMATIC TRANSMISSION When the DTC about automatic transmission is shown on display, carry out the following basic check. After that, carry out the replacement or re- pair work. 1) ATF level check <Ref. to 4AT-31, Automatic Transmission Fluid.>...

  • Page 310: Check List For Interview

    Check List for Interview ENGINE (DIAGNOSTICS) 2. Check List for Interview A: CHECK 1. CHECK LIST No. 1 Check the following items when problem has occurred. NOTE: Use copies of this page for interviewing customers. Customer’s name Engine No. Date of sale Fuel brand Date of repair Odometer reading...
  • Page 311 Check List for Interview ENGINE (DIAGNOSTICS) 2. CHECK LIST No. 2 Check the following items about the vehicle’s state when malfunction indicator light turns on. NOTE: Use copies of this page for interviewing customers. a) Other warning lights or indicators turn on. ❏ Yes / ❏ No ❏...

  • Page 312: General Description

    General Description ENGINE (DIAGNOSTICS) 3. General Description 8) Use ECM mounting stud bolts at the body side grounding point when measuring voltage and resis- A: CAUTION tance inside the passenger compartment. 1) Airbag system wiring harness is routed near the ECM, main relay and fuel pump relay.
  • Page 313 General Description ENGINE (DIAGNOSTICS) 12) Observe the following cautions when installing 2) Check the condition of the main and other fuses, a radio in MFI equipped models. and harnesses and connectors. Also check for proper grounding. CAUTION: • The antenna must be kept as far apart as pos- 2.
  • Page 314 TOOL NUMBER DESCRIPTION REMARKS 24082AA230 CARTRIDGE Troubleshooting for electrical systems. ST24082AA230 22771AA030 SUBARU SELECT Troubleshooting for electrical systems. MONITOR KIT • English: 22771AA030 (Without printer) • German: 22771AA070 (Without printer) • French: 22771AA080 (Without printer) • Spanish: 22771AA090 (Without printer) ST22771AA030...

  • Page 315: Electrical Components Location

    Electrical Components Location ENGINE (DIAGNOSTICS) 4. Electrical Components Location A: LOCATION 1. ENGINE • MODULE EN-01397 EN-01398 Engine control module (ECM) Test mode connector Data link connector Malfunction indicator light EN(H4SO)(diag)-9...
  • Page 316 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01399 EN-00156 EN-01149 EN-01150 EN(H4SO)(diag)-10...
  • Page 317 Electrical Components Location ENGINE (DIAGNOSTICS) • SENSOR EN-01400 Intake air temperature sensor Engine coolant temperature sen- Knock sensor Manifold absolute pressure sen- Camshaft position sensor Throttle position sensor Crankshaft position sensor EN(H4SO)(diag)-11...
  • Page 318 Electrical Components Location ENGINE (DIAGNOSTICS) ( 2) EN-00160 EN-00006 EN-00008 EN-00161 EN-00010 EN-00011 EN-00012 EN(H4SO)(diag)-12...
  • Page 319 Electrical Components Location ENGINE (DIAGNOSTICS) EN-00162 Front oxygen (A/F) sensor Front catalytic converter Rear catalytic converter Rear oxygen sensor EN-00014 EN-00163 EN-00016 EN-00164 EN(H4SO)(diag)-13...
  • Page 320 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01401 EN-01402 Fuel level sensor EN-01403 EN(H4SO)(diag)-14...
  • Page 321 Electrical Components Location ENGINE (DIAGNOSTICS) • SOLENOID VALVE, EMISSION CONTROL SYSTEM PARTS AND IGNITION SYSTEM PARTS EN-01404 Idle air control solenoid valve Air assisted injector solenoid valve EGR valve (1.6 L model) Purge control solenoid valve Ignition coil & ignitor ASSY EN(H4SO)(diag)-15...
  • Page 322 Electrical Components Location ENGINE (DIAGNOSTICS) (1 ) EN-00249 EN-00250 EN-01595 EN-00251 EN-01590 EN(H4SO)(diag)-16...
  • Page 323 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01405 EN-01406 Inhibitor switch Fuel pump relay Starter Fuel pump Radiator main fan relay Main relay Radiator sub fan relay EN(H4SO)(diag)-17...
  • Page 324 Electrical Components Location ENGINE (DIAGNOSTICS) EN-00178 EN-01407 EN-01408 EN-01409 EN-00180 EN-00181 EN(H4SO)(diag)-18...
  • Page 325 Electrical Components Location ENGINE (DIAGNOSTICS) 2. TRANSMISSION • MODULE EN-01410 EN-01411 Transmission control module AT diagnostic indicator light (AT (TCM) (AT model) model) EN(H4SO)(diag)-19...
  • Page 326 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01413 EN-01412 EN-01414 EN(H4SO)(diag)-20...
  • Page 327 Electrical Components Location ENGINE (DIAGNOSTICS) • SENSOR EN-00184 EN-00107 EN-00186 EN-00187 EN-00188 Rear vehicle speed sensor (AT Front vehicle speed sensor (AT ATF temperature sensor (AT model) model) model) Front vehicle speed sensor (MT Torque converter turbine speed Brake light switch model) sensor EN(H4SO)(diag)-21...
  • Page 328 Electrical Components Location ENGINE (DIAGNOSTICS) • SOLENOID VALVE AND SWITCH (AT MODELS) AT-00334 AT-00335 EN-01415 Shift solenoid valve 1 Low clutch timing solenoid 2-4 brake timing solenoid Shift solenoid valve 2 Lock up duty solenoid Transfer duty solenoid Line pressure duty solenoid 2-4 brake duty solenoid Inhibitor switch •...
  • Page 329 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) 5. Engine Control Module (ECM) I/O Signal A: ELECTRICAL SPECIFICATION B134 B135 B137 B136 EN-00258 Signal (V) Connector Terminal Content Note Ignition SW ON Engine ON (Idling) (Engine OFF) −7 to +7 Signal (+) B135 Sensor output waveform...
  • Page 330 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) Signal (V) Connector Terminal Content Note Ignition SW ON Engine ON (Idling) (Engine OFF) ON: 10 — 13 ON: 12 — 14 A/C switch B136 — OFF: 0 OFF: 0 Ignition switch B136 10 —...
  • Page 331 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) Signal (V) Connector Terminal Content Note Ignition SW ON Engine ON (Idling) (Engine OFF) ON: 0 ON: 0 Small light switch B137 — OFF: 10 — 13 OFF: 12 — 14 ON: 0 ON: 0 Blower fan switch B137...

  • Page 332: Engine Condition Data

    Engine Condition Data ENGINE (DIAGNOSTICS) 6. Engine Condition Data A: ELECTRICAL SPECIFICATION Content Specified data 1.6 — 2.9 (%): Idling Engine load 6.4 — 12.8 (%): 2,500 rpm racing Measuring condition: • After the engine is warmed-up. • Gear position is in “N” or “P” range. •...

  • Page 333: Transmission Control Module (Tcm) I/O Signal

    Transmission Control Module (TCM) I/O Signal ENGINE (DIAGNOSTICS) 7. Transmission Control Mod- ule (TCM) I/O Signal A: ELECTRICAL SPECIFICATION For electrical specification of TCM I/O signal, refer to 4AT section. <Ref. to 4AT(diag)-13, ELECTRI- CAL SPECIFICATION, Transmission Control Mod- ule (TCM) I/O Signal.> EN(H4SO)(diag)-27...
  • Page 334 This connector is used both for OBD-II general scan tools and the Subaru Select Monitor. CAUTION: Do not connect any scan tools other than the OBD-II general scan tools and the Subaru Select Mon- itor, because the circuit for the Subaru Select Monitor may be damaged.

  • Page 335: Obd-Ii General Scan Tool

    OBD-II General Scan Tool ENGINE (DIAGNOSTICS) 9. OBD-II General Scan Tool A: OPERATION 1. HOW TO USE OBD-II GENERAL SCAN TOOL 1) Prepare a general scan tool (OBD-II general scan tool) required by SAE J1978. 2) Connect the OBD-II general scan tool to data link connector located in the lower portion of the in- strument panel (on driver’s side).
  • Page 336 OBD-II General Scan Tool ENGINE (DIAGNOSTICS) 2. MODE $01 (CURRENT POWERTRAIN DIAGNOSTIC DATA) Refers to data denoting the current operating condition of analog input/output, digital input/output or the pow- ertrain system. A list of the support data and PID (Parameter Identification) codes are shown in the following table. Data Unit of measure Number of emission-related powertrain DTC and malfunction indicator light status...
  • Page 337 OBD-II General Scan Tool ENGINE (DIAGNOSTICS) 4. MODE $03 (EMISSION-RELATED POWERTRAIN DIAGNOSTIC TROUBLE CODE (DTC)) Refer to Read Diagnostic Trouble Code (DTC) for information about data denoting emission-related power- train DTC. <Ref. to EN(H4SO)(diag)-39, Read Diagnostic Trouble Code (DTC).> 5. MODE $04 (CLEAR/RESET EMISSION-RELATED DIAGNOSTIC INFORMATION) Refers to mode used to clear or reset emission-related diagnostic information (OBD-II trouble diagnostic in- formation).

  • Page 338: Subaru Select Monitor

    Select Monitor and OBD-II general scan tool. 5) Turn the ignition switch to ON (engine OFF) and 1. HOW TO USE SUBARU SELECT MONI- Subaru Select Monitor switch to ON. 1) Prepare the Subaru Select Monitor kit. <Ref. to EN(H4SO)(diag)-8, PREPARATION TOOL, Gen- eral Description.> EN-00040...
  • Page 339 Subaru Select Monitor ENGINE (DIAGNOSTICS) 4. READ CURRENT DATA FOR ENGINE (NORMAL MODE) 1) On «Main Menu» display screen, select the {Each System Check} and press the [YES] key. 2) On «System Selection Menu» display screen, select the {Engine Control System} and press the [YES] key.
  • Page 340 Torque Control Signal #1 — Engine torque control signal #2 Torque Control Signal #2 — Torque Permission Sig- Engine torque control permission signal — ON or OFF NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SO)(diag)-34...
  • Page 341 Short term fuel trim #12 On-board diagnostic system OBD System — A/F sensor check A/F sensor — A/F sensor #11 A/F sensor #11 A/F sensor #11 A/F sensor #11 — NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SO)(diag)-35...
  • Page 342 Intake manifold absolute pressure signal Mani. Absolute Pressure mmHg, kPa, inHg or psi Engine speed signal Engine Speed Vehicle speed signal Vehicle Speed km/h or MPH NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SO)(diag)-36...
  • Page 343 ON or OFF signal 2 is entered. Engine torque control permis- When engine torque control Torque Control Permit ON or OFF sion signal permission signal is entered. NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SO)(diag)-37...
  • Page 344 ON or OFF Low clutch timing control solenoid valve Low Clutch Timing Sol. ON or OFF Automatic transmission diagnosis indicator light AT Diagnosis light ON or OFF NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SO)(diag)-38...

  • Page 345: Read Diagnostic Trouble Code (Dtc)

    For details concerning DTC, refer to the List of Di- agnostic Trouble Code (DTC). <Ref. 1. SUBARU SELECT MONITOR (NORMAL EN(H4SO)(diag)-74, List of Diagnostic Trouble MODE) Code (DTC).> 1) On «Main Menu» display screen, select the NOTE: {Each System Check} and press the [YES] key.

  • Page 346: Inspection Mode

    Inspection Mode ENGINE (DIAGNOSTICS) 12.Inspection Mode A: OPERATION Carry out trouble diagnosis shown in the following DTC table. When performing trouble diagnosis which is not shown in the DTC table, refer to the next item Drive cycle. <Ref. to EN(H4SO)(diag)-45, Drive Cycle.> Item P0031 HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
  • Page 347 Inspection Mode ENGINE (DIAGNOSTICS) Item P0732 Gear 2 Incorrect Ratio P0733 Gear 3 Incorrect Ratio P0734 Gear 4 Incorrect Ratio P0741 Torque Converter Clutch Circuit Performance or Stuck Off P0743 Torque Converter Clutch Circuit Electrical P0748 Pressure Control Solenoid “A” Electrical P0753 Shift Solenoid “A”...
  • Page 348 12 V or more. 2) Raise the vehicle using a garage jack and place 3) Prepare the Subaru Select Monitor kit. <Ref. to EN(H4SO)(diag)-8, PREPARATION TOOL, Gen- on safety stands or drive the vehicle onto free roll- eral Description.>...
  • Page 349 (on the driver’s side). ru Select Monitor and OBD-II general scan tool. 8) Turn the ignition switch to ON (engine OFF) and Subaru Select Monitor switch to ON. EN-01164 4) Connect the OBD-II general scan tool to its data...
  • Page 350 Inspection Mode ENGINE (DIAGNOSTICS) 7) Depress the brake pedal to turn brake switch ON. (AT models) 8) Keep the engine speed in 2,500 — 3,000 rpm range for 40 seconds. 9) Place the selector lever or shift lever in “D” posi- tion (AT models) or “1st”...

  • Page 351: Drive Cycle

    Drive Cycle ENGINE (DIAGNOSTICS) 13.Drive Cycle A: OPERATION There are three drive patterns for the trouble diagnosis. Driving in the specified pattern allows to diagnose malfunctioning items listed below. After the malfunctioning items listed below are repaired, always check whether they correctly resume their functions by driving in the required drive pattern. 1.
  • Page 352 Drive Cycle ENGINE (DIAGNOSTICS) 4. DRIVE ACCORDING TO THE FOLLOWING DRIVE PATTERN Vehicle speed km/h (MPH) 96 (60) 65 (40) (Seconds) EN-00195 Idle engine for 1 minute. Decelerate with fully closed throt- Accelerate to 96 km/h (60 MPH) tle to 65 km/h (40 MPH). within 10 seconds.
  • Page 353 {Clear Memory} and press the [YES] key. 5) When the ‘Done’ and ‘Turn Ignition Switch OFF’ are shown on display screen, turn the ignition switch to OFF, and then turn the Subaru Select Monitor to OFF. NOTE: • After the memory has been cleared, the idle air control solenoid valve must be initialized.

  • Page 354: Compulsory Valve Operation Check Mode

    (1) Data link connector is located in the lower portion of instrument panel (on driver’s side). Check Mode A: OPERATION 1) Prepare the Subaru Select Monitor kit. <Ref. to EN(H4SO)(diag)-8, PREPARATION TOOL, Gen- eral Description.> IM-00072 (2) Connect the diagnosis cable to data link connector.
  • Page 355 Compulsory Valve Operation Check Mode ENGINE (DIAGNOSTICS) 13) Pressing the [NO] key completes the compul- sory operation check mode. The display will then return to the «Actuator ON/OFF Operation» screen. • A list of support data is shown in the following ta- ble.

  • Page 356: Malfunction Indicator Light

    Malfunction Indicator Light ENGINE (DIAGNOSTICS) 16.Malfunction Indicator Light A: PROCEDURE 1. Activation of malfunction indicator light. <Ref. to EN(H4SO)(diag)-51, ACTIVATION OF MALFUNCTION INDICATOR LIGHT, Malfunction Indicator Light.> ↓ 2. Malfunction indicator light does not come on. <Ref. to EN(H4SO)(diag)-52, MALFUNCTION INDICATOR LIGHT DOES NOT COME ON., Malfunction Indicator Light.>...
  • Page 357 Malfunction Indicator Light ENGINE (DIAGNOSTICS) B: ACTIVATION OF MALFUNCTION 4) When the ignition switch is turned to ON (engine off) or to “START” with test mode connector con- INDICATOR LIGHT nected, the malfunction indicator light blinks at a 1) When the ignition switch is turned to ON (engine cycle of 3 Hz.
  • Page 358 Malfunction Indicator Light ENGINE (DIAGNOSTICS) C: MALFUNCTION INDICATOR LIGHT DOES NOT COME ON. • DIAGNOSIS: • The malfunction indicator light circuit is open or shorted. • TROUBLE SYMPTOM: • When the ignition switch is turned ON (engine OFF), malfunction indicator light does not come on. •...
  • Page 359 Malfunction Indicator Light ENGINE (DIAGNOSTICS) Step Check CHECK ECM CONNECTOR. Is the ECM connector correctly Replace the ECM. Repair connection Check the ECM connector connection. connected? <Ref. to of ECM connector. FU(H4SO)-47, Engine Control Module (ECM).> CHECK HARNESS BETWEEN COMBINA- Is the resistance less than 1 Go to step 5.
  • Page 360 • The malfunction indicator light circuit is shorted. • TROUBLE SYMPTOM: • Although malfunction indicator light comes on when the engine runs, DTC is not shown on Subaru se- lect monitor or OBD-II general scan tool display. • WIRING DIAGRAM:...
  • Page 361 Malfunction Indicator Light ENGINE (DIAGNOSTICS) E: MALFUNCTION INDICATOR LIGHT DOES NOT BLINK AT A CYCLE OF 3 HZ. • DIAGNOSIS: • The malfunction indicator light circuit is open or shorted. • Test mode connector circuit is in open. • TROUBLE SYMPTOM: •...
  • Page 362 Malfunction Indicator Light ENGINE (DIAGNOSTICS) Step Check CHECK STATUS OF MALFUNCTION INDI- Dose the malfunction indicator Go to step 2. Repair the mal- CATOR LIGHT. light illuminate? function indicator 1)Turn the ignition switch to OFF. light circuit. <Ref. 2)Disconnect the test mode connector. 3)Turn the ignition switch to ON.
  • Page 363 Malfunction Indicator Light ENGINE (DIAGNOSTICS) F: MALFUNCTION INDICATOR LIGHT REMAINS BLINKING AT A CYCLE OF 3 • DIAGNOSIS: • Test mode connector circuit is shorted. • TROUBLE SYMPTOM: • Malfunction indicator light blinks at a cycle of 3 Hz when the ignition switch is turned to ON. •...
  • Page 364 Malfunction Indicator Light ENGINE (DIAGNOSTICS) Step Check CHECK TEST MODE CONNECTOR. Dose the malfunction indicator Go to step 2. System is in good 1)Disconnect the test mode connector. light blink? order. 2)Turn the ignition switch to ON. NOTE: Malfunction indica- tor light blinks at a cycle of 3 Hz when test mode connec-...
  • Page 365 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) 17.Diagnostics for Engine Starting Failure A: PROCEDURE 1. Check for fuel amount. ↓ 2. Inspection of starter motor circuit. <Ref. to EN(H4SO)(diag)-60, STARTER MOTOR CIRCUIT, Diagnostics for Engine Start- ing Failure.> ↓ 3. Inspection of ECM power supply and ground line. <Ref. to EN(H4SO)(diag)-63, CONTROL MODULE POWER SUPPLY AND GROUND LINE, Diagnostics for Engine Starting Failure.>...

  • Page 366: Diagnostics For Engine Starting Failure

    Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) B: STARTER MOTOR CIRCUIT CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>. • WIRING DIAGRAM: IGNITION SWITCH BATTERY...
  • Page 367 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK BATTERY. Is the voltage more than 12 V? Go to step 2. Charge or replace Check the battery voltage. the battery. CHECK INPUT SIGNAL FOR STARTER MO- Is the voltage more than 10 V? Go to step 3. Go to step 4.
  • Page 368 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK INHIBITOR SWITCH. Is the resistance less than 1 Repair open or Replace the inhibi- Ω? 1)Place the select lever in the “P” or “N” range. ground short cir- tor switch. <Ref. to 2)Measure the resistance between inhibitor cuit in harness 4AT-52, Inhibitor...
  • Page 369 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) C: CONTROL MODULE POWER SUPPLY AND GROUND LINE CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>.
  • Page 370 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK GROUND CIRCUIT OF ECM. Is the resistance less than 5 Go to step 3. Repair open circuit Ω? 1)Disconnect the connector from ECM. in harness 2)Measure the resistance of harness between between ECM ECM and chassis ground.
  • Page 371 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK INPUT VOLTAGE OF ECM. Is the voltage more than 10 V? Check ignition Repair open or 1)Connect the main relay connector. control system. ground short cir- 2)Turn the ignition switch to ON. <Ref.
  • Page 372 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) D: IGNITION CONTROL SYSTEM CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>. • WIRING DIAGRAM: B136 B134 IGNITION...
  • Page 373 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK IGNITION SYSTEM FOR SPARKS. Does spark occur at each cyl- Check fuel pump Go to step 2. 1)Remove the plug cord cap from each spark inder? system. <Ref. to plug. EN(H4SO)(diag)- 2)Install the new spark plug on plug cord cap.
  • Page 374 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND IG- Is the resistance less than 1 Go to step 7. Repair harness Ω? NITION COIL & IGNITOR ASSY CONNEC- and connector. TOR. NOTE: 1)Turn the ignition switch to OFF. In this case, repair 2)Disconnect the connector from ECM.
  • Page 375 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) E: FUEL PUMP CIRCUIT CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>. • WIRING DIAGRAM: SBF-5 IGNITION BATTERY...
  • Page 376 Diagnostics for NOTE: Engine Starting Fuel pump operation can also be executed us- Failure.> ing Subaru Select Monitor. For the procedure, refer to “Compulsory Valve Operation Check Mode”. <Ref. to EN(H4SO)(diag)-48, Compulsory Valve Oper- ation Check Mode.> CHECK GROUND CIRCUIT OF FUEL PUMP.
  • Page 377 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK FUEL PUMP RELAY. Is the resistance less than 10 Go to step 7. Replace the fuel Ω? 1)Disconnect the connectors from fuel pump pump relay. <Ref. relay and main relay. to FU(H4SO)-49, 2)Remove the fuel pump relay and main relay Fuel Pump...
  • Page 378 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) F: FUEL INJECTOR CIRCUIT CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>. • WIRING DIAGRAM: MAIN RELAY BATTERY SBF-5...
  • Page 379 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO EACH FUEL Is the voltage more than 10 V? Go to step 3. Repair harness INJECTOR. and connector. 1)Turn the ignition switch to OFF. NOTE: 2)Disconnect the connector from #1 cylinder In this case, repair fuel injector.

  • Page 380: List Of Diagnostic Trouble Code (Dtc)

    List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) 18.List of Diagnostic Trouble Code (DTC) A: LIST Item Index P0030 HO2S Heater Control Circuit (Bank 1 <Ref. to EN(H4SO)(diag)-80, DTC P0030 HO2S HEATER CONTROL CIR- Sensor 1) CUIT (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>...

  • Page 381: Diagnostic Procedure With Diagnostic Trouble Code (Dtc)

    List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Index P0129 Atmospheric Pressure Sensor Circuit <Ref. to EN(H4SO)(diag)-122, DTC P0129 ATMOSPHERIC PRESSURE Range/Performance SENSOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> P0130 O2 Sensor Circuit (Bank 1 Sensor 1) <Ref.
  • Page 382 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Index P0400 Exhaust Gas Recirculation Flow <Ref. to EN(H4SO)(diag)-165, DTC P0400 EXHAUST GAS RECIRCULA- TION FLOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> P0420 Catalyst System Efficiency Below <Ref. to EN(H4SO)(diag)-168, DTC P0420 CATALYST SYSTEM EFFI- Threshold (Bank 1) CIENCY BELOW THRESHOLD (BANK 1), Diagnostic Procedure with Diag- nostic Trouble Code (DTC).>...
  • Page 383 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Index P0705 Transmission Range Sensor Circuit <Ref. to 4AT(diag)-107, CHECK INHIBITOR SWITCH, Diagnostic Procedure (PRNDL Input) without Diagnostic Trouble Code (DTC).> P0710 Transmission Fluid Temperature Sen- <Ref. to 4AT(diag)-44, DTC 27 ATF TEMPERATURE SENSOR, Diagnostic sor Circuit Procedure with Diagnostic Trouble Code (DTC).>...
  • Page 384 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Index P1111 Atmospheric Pressure Sensor Circuit <Ref. to EN(H4SO)(diag)-232, DTC P1111 ATMOSPHERIC PRESSURE Malfunction (High Input) SENSOR CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with Diagnostic Trouble Code (DTC).> P1134 A/F Sensor Micro-computer Problem <Ref.
  • Page 385 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Index P1518 Starter Switch Circuit Low input <Ref. to EN(H4SO)(diag)-247, DTC P1518 STARTER SWITCH CIRCUIT LOW INPUT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> P1560 Back-up Voltage Circuit Malfunction <Ref. to EN(H4SO)(diag)-250, DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>...
  • Page 386 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) 19.Diagnostic Procedure with Diagnostic Trouble Code (DTC) A: DTC P0030 HO2S HEATER CONTROL CIRCUIT (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 387 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 388 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 389 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) 19.Diagnostic Procedure with Diagnostic Trouble Code (DTC) A: DTC P0030 HO2S HEATER CONTROL CIRCUIT (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 390 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 1 Go to step 2. Repair the open Ω? FRONT OXYGEN (A/F) SENSOR CONNEC- circuit in harness TOR. between ECM and 1)Start the engine and warm-up engine.
  • Page 391 13 14 15 16 EN-01421 Step Check CHECK ANY OTHER DTC ON DISPLAY. Does the Subaru Select Moni- Go to step 2. Go to step 5. tor or OBD-II general scan tool display DTC P0031 and P0037 at the same time?
  • Page 392 Go to step 5. 1)Start the engine. tact in connector. 2)Read the data of front oxygen (A/F) sensor NOTE: heater current using Subaru Select Monitor or In this case, repair OBD-II general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 393 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK FRONT OXYGEN (A/F) SENSOR. Is the resistance less than 10 Repair harness Replace the front Ω? 1)Turn the ignition switch to OFF. and connector. oxygen (A/F) sen- 2)Measure the resistance between front oxy- sor.
  • Page 394 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) C: DTC P0032 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 395 Module (ECM).> connector. 3)Turn the ignition switch to ON. 4)Read the data of front oxygen (A/F) sensor heater current using Subaru Select Monitor or the OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 396 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) D: DTC P0037 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 397 Is the current more than 0.2 A? Repair the con- Go to step 3. 1)Start the engine. nector. 2)Read the data of rear oxygen sensor heater NOTE: current using Subaru Select Monitor or OBD-II In this case, repair general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 398 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO REAR OXY- Is the voltage more than 10 V? Go to step 7. Repair power sup- GEN SENSOR. ply line. 1)Turn the ignition switch to OFF. NOTE: 2)Disconnect the connector from rear oxygen In this case, repair...
  • Page 399 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) E: DTC P0038 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 2) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 400 Engine Control tor. Module (ECM).> 3)Turn the ignition switch to ON. 4)Read the data of rear oxygen sensor heater current using Subaru Select Monitor or the OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 401 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) F: DTC P0066 AIR ASSISTED INJECTOR CONTROL CIRCUIT OR CIRCUIT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 402 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OUTPUT SIGNAL FROM ECM. Is the voltage more than 10 V? Repair poor con- Go to step 2. 1)Turn ignition switch to ON. tact in ECM con- 2)Measure voltage between ECM and chassis nector.
  • Page 403 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) G: DTC P0067 AIR ASSISTED INJECTOR CONTROL CIRCUIT HIGH • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 404 CHECK OUTPUT SIGNAL FROM ECM. Does the voltage change by Repair battery Contact with your Measure voltage between ECM and chassis shaking the ECM harness and short circuit in har- Subaru distributor ground. connector? ness between service. Connector & terminal ECM and air assist NOTE: (B134) No.
  • Page 405 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) H: DTC P0107 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 406 Go to step 2. 1)Start the engine. than 13.3 kPa (100 mmHg, 2)Read the data of intake manifold absolute 3.94 inHg)? pressure signal using Subaru Select Monitor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 407 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN MANIFOLD Is the voltage more than 4.5 V? Go to step 8. Repair open circuit ABSOLUTE PRESSURE SENSOR AND ECM in harness CONNECTOR. between ECM and 1)Turn the ignition switch to OFF.
  • Page 408 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) I: DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 409 Go to step 2. 1)Start the engine. than 119.5 kPa (896.5 mmHg, 2)Read the data of intake manifold absolute 35.29 inHg)? pressure signal using Subaru Select Monitor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 410 CONNECTOR. 35.29 inHg)? ness between sure sensor. <Ref. 1)Turn the ignition switch to OFF and Subaru ECM and manifold to FU(H4SO)-33, Select Monitor or the OBD-II general scan tool absolute pressure Manifold Absolute switch to OFF.
  • Page 411 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) J: DTC P0111 INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFORMANCE • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 412 1)Start the engine and warm it up completely. (203°F)? sensor. <Ref. to of Diagnostic 2)Measure the engine coolant temperature FU(H4SO)-34, Trouble Code using Subaru Select Monitor or OBD-II general Intake Air Temper- (DTC)”. <Ref. to scan tool. ature Sensor.> EN(H4SO)(diag)- 74, List of Diag-...
  • Page 413 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) K: DTC P0112 INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 414 1)Start the engine. more than 120°C (248°F)? tact. 2)Read the data of intake air temperature sen- NOTE: sor signal using Subaru Select Monitor or the In this case, repair OBD-II general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 415 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) L: DTC P0113 INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 416 −40°C (−40°F)? 1)Start the engine. tact. 2)Read the data of intake air temperature sen- NOTE: sor signal using Subaru Select Monitor or the In this case, repair OBD-II general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 417 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN INTAKE AIR Is the resistance less than 5 Replace the intake Repair harness Ω? TEMPERATURE SENSOR AND ECM CON- air temperature and connector. NECTOR. sensor. <Ref. to NOTE: 1)Turn the ignition switch to OFF.
  • Page 418 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) M: DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Hard to start • Erroneous idling • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 419 Repair poor con- 1)Start the engine. ture more than 150°C (302°F)? tact. 2)Read the data of engine coolant temperature NOTE: sensor signal using Subaru Select Monitor or In this case, repair OBD-II general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 420 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) N: DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Hard to start • Erroneous idling • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 421 Repair poor con- ture less than −40°C (−40°F)? 1)Start the engine. tact. 2)Read the data of engine coolant temperature NOTE: sensor signal using Subaru Select Monitor or In this case, repair OBD-II general scan tool. the following: • Poor contact in NOTE: •Subaru Select Monitor...
  • Page 422 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ENGINE Is the resistance less than 5 Replace the Repair harness Ω? COOLANT TEMPERATURE SENSOR AND engine coolant and connector. ECM CONNECTOR. temperature sen- NOTE: 1)Turn the ignition switch to OFF. sor.
  • Page 423 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) O: DTC P0121 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT RANGE/PERFORMANCE • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 424 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC Replace the throt- P0122 or P0123 tle position sen- using “List of Diag- sor. <Ref. to nostic Trouble FU(H4SO)-31, Code (DTC)”.
  • Page 425 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) P: DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 426 Even if malfunction 1)Start the engine. indicator light 2)Read the data of throttle position sensor sig- lights up, the cir- nal using Subaru Select Monitor or OBD-II cuit has returned general scan tool. to a normal condi- tion at this time. A...
  • Page 427 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the voltage more than 4.5 V? Go to step 7. Repair harness THROTTLE POSITION SENSOR CONNEC- and connector. TOR. NOTE: 1)Turn the ignition switch to OFF. In this case, repair 2)Disconnect the connectors from throttle posi- the following:...
  • Page 428 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Q: DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 429 Even if malfunction 1)Start the engine. indicator light 2)Read the data of throttle position sensor sig- lights up, the cir- nal using Subaru Select Monitor or OBD-II cuit has returned general scan tool. to a normal condi- tion at this time. A...
  • Page 430 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) R: DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Engine would not return to idling. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 431 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 432 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) T: DTC P0130 O2 SENSOR CIRCUIT (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 433 70°C (160°F). If the engine is already warmed-up, operate at idle speed for at least 1 minute. 3)Read the data of front oxygen (A/F) sensor signal using Subaru Select Monitor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 434 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK EXHAUST SYSTEM. Is there a fault in exhaust sys- Repair or replace Replace the front Check exhaust system parts. tem? faulty parts. oxygen (A/F) sen- sor. <Ref. to NOTE: FU(H4SO)-43, Check the following items.
  • Page 435 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) U: DTC P0131 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 436 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance more than 1 Replace the front Repair ground FRONT OXYGEN (A/F) SENSOR CONNEC- MΩ? oxygen (A/F) sen- short circuit in har- TOR.
  • Page 437 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) V: DTC P0132 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 438 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the voltage more than 8 V? Replace the front Repair battery FRONT OXYGEN (A/F) SENSOR CONNEC- oxygen (A/F) sen- short circuit in har- TOR.
  • Page 439 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) W: DTC P0133 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 1) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 440 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 441 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) X: DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SEN- SOR 1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 442 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 1 Go to step 2. Repair harness Ω? FRONT OXYGEN (A/F) SENSOR CONNEC- and connector. TOR. NOTE: 1)Turn the ignition switch to OFF. In this case, repair 2)Disconnect the connectors from ECM and the following:...
  • Page 443 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Y: DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 444 1)Warm-up the engine until engine coolant temperature is above 70°C (158°F), and keep the engine speed at 5,000 rpm for two minutes. 2)Read the data of rear oxygen sensor signal using Subaru Select Monitor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA SHOWN ON DIS-...
  • Page 445 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK EXHAUST SYSTEM. Is there a fault in exhaust sys- Repair or replace Replace the rear Check exhaust system parts. tem? faulty parts. oxygen sensor. <Ref. to NOTE: FU(H4SO)-43, Check the following items.
  • Page 446 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Z: DTC P0138 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 2) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 447 70°C (158°F), and imme- diately decrease the engine speed from 5,000 rpm. 2)Read the data of rear oxygen sensor signal using Subaru Select Monitor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA SHOWN ON DIS-...
  • Page 448 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK EXHAUST SYSTEM. Is there a fault in exhaust sys- Repair or replace Replace the rear Check exhaust system parts. tem? faulty parts. oxygen sensor. <Ref. to NOTE: FU(H4SO)-43, Check the following items.
  • Page 449 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AA:DTC P0139 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 2) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 450 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using Replace the rear “List of Diagnostic oxygen sensor. Trouble Code <Ref. to (DTC)”. <Ref. to FU(H4SO)-43, EN(H4SO)(diag)- Front Oxygen (A/...
  • Page 451 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AC:DTC P0172 SYSTEM TOO RICH (BANK 1) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 452 70 — 100°C (158 — engine coolant 1)Start the engine and warm-up completely. 212°F)? temperature sen- 2)Read the data of engine coolant temperature sor. <Ref. to sensor signal using Subaru Select Monitor or FU(H4SO)-27, OBD-II general scan tool. Engine Coolant Temperature Sen- NOTE: sor.>...
  • Page 453 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AD:DTC P0301 CYLINDER 1 MISFIRE DETECTED NOTE: For the diagnostic procedure, refer to DTC P0304. <Ref. to EN(H4SO)(diag)-145, DTC P0304 CYLINDER 4 MISFIRE DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> AE:DTC P0302 CYLINDER 2 MISFIRE DETECTED NOTE: For the diagnostic procedure, refer to DTC P0304.
  • Page 454 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AG:DTC P0304 CYLINDER 4 MISFIRE DETECTED • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • Immediately at fault recognition (A misfire which could damage catalyst occurs.) • TROUBLE SYMPTOM: •...
  • Page 455 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 456 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY LINE. Is the voltage more than 10 V? Repair poor con- Repair harness 1)Turn the ignition switch to ON. tact in all connec- and connector. 2)Measure the voltage between fuel injector tors in fuel injector NOTE: and engine ground on faulty cylinders.
  • Page 457 Does the malfunction indicator Go to step 15. Go to step 14. CATOR LIGHT. light illuminate or blink? 1)Clear the memory using Subaru Select Mon- itor. <Ref. to EN(H4SO)(diag)-47, Clear Memory Mode.> 2)Start the engine, and drive the vehicle more than 10 minutes.
  • Page 458 • Are there cracks or any disconnec- tion of hoses? CHECK MISFIRE SYMPTOM. Does the Subaru Select Moni- Go to step 21. Go to step 17. 1)Turn the ignition switch to ON. tor or OBD-II general scan tool 2)Read the DTC.
  • Page 459 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check GROUP OF #1 AND #2 CYLINDERS Are there faults in #1 and #2 Repair or replace Go to DTC P0171. cylinders? faulty parts. <Ref. to EN(H4SO)(diag)- NOTE: 141, DTC P0171 •...
  • Page 460 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check GROUP OF #2 AND #4 CYLINDERS Are there faults in #2 and #4 Repair or replace Go to DTC P0171. cylinders? faulty parts. <Ref. to EN(H4SO)(diag)- NOTE: 141, DTC P0171 Check the follow- SYSTEM TOO ing items.
  • Page 461 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AH:DTC P0327 KNOCK SENSOR 1 CIRCUIT LOW INPUT (BANK 1 OR SINGLE SENSOR) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Poor driving performance • Knocking occurs. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 462 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN KNOCK SEN- Is the resistance more than Go to step 2. Repair harness SOR AND ECM CONNECTOR. 700 kΩ? and connector. 1)Turn the ignition switch to OFF. NOTE: 2)Disconnect the connector from ECM.
  • Page 463 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AI: DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH INPUT (BANK 1 OR SINGLE SENSOR) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Poor driving performance • Knocking occurs. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 464 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN KNOCK SEN- Is the resistance less than 400 Go to step 2. Go to step 3. SOR AND ECM CONNECTOR. kΩ? Measure the resistance of harness between ECM connector and chassis ground.
  • Page 465 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AJ:DTC P0335 CRANKSHAFT POSITION SENSOR “A” CIRCUIT • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine stalls. • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 466 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN CRANK- Is the resistance more than Repair harness Go to step 2. SHAFT POSITION SENSOR AND ECM CON- 100 kΩ? and connector. NECTOR. NOTE: 1)Turn the ignition switch to OFF. In this case, repair 2)Disconnect the connector from crankshaft the following:...
  • Page 467 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AK:DTC P0336 CRANKSHAFT POSITION SENSOR “A” CIRCUIT RANGE/PER- FORMANCE • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine stalls. • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 468 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 469 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AL:DTC P0340 CAMSHAFT POSITION SENSOR “A” CIRCUIT (BANK 1 OR SIN- GLE SENSOR) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine stalls. • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 470 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN CAMSHAFT Is the resistance more than Repair harness Go to step 2. POSITION SENSOR AND ECM CONNEC- 100 kΩ? and connector. TOR. NOTE: 1)Turn the ignition switch to OFF. In this case, repair 2)Disconnect the connector from camshaft the following:...
  • Page 471 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AM:DTC P0341 CAMSHAFT POSITION SENSOR “A” CIRCUIT RANGE/PERFOR- MANCE (BANK 1 OR SINGLE SENSOR) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine stalls. • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 472 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 473 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK CONDITION OF CAMSHAFT POSI- Is the camshaft position sensor Go to step 8. Tighten camshaft TION SENSOR. installation bolt tightened position sensor Turn the ignition switch to OFF. securely? installation bolt securely.
  • Page 474 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AN:DTC P0400 EXHAUST GAS RECIRCULATION FLOW • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Poor driving performance on low engine speed • Erroneous idling •...
  • Page 475 1)Start engine. than 53.3 kPa (400 mmHg, valve, intake mani- 2)Rear the data of intake manifold absolute 15.75 inHg)? fold pressure sen- pressure signal using Subaru Select Monitor or sor and throttle OBD-II general scan tool. body are securely installed. NOTE: •Subaru Select Monitor...
  • Page 476 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN EGR SOLE- Is the resistance less than 1 Go to step 7. Repair the open Ω? NOID VALVE AND ECM CONNECTOR. circuit in harness 1)Turn the ignition switch to OFF. between ECM and 2)Disconnect the connectors from EGR sole- EGR solenoid...
  • Page 477 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AO:DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Engine stalls. • Idle mixture is out of specifications. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 478 2)Measure the resistance between rear oxy- sor. gen sensor connector and ECM connector. Connector & terminal (B19) No. 3 — (B135) No. 19: CHECK SHIELD HARNESS. Is the shield harness opened? Repair the shield Contact with your harness. Subaru distributor service. EN(H4SO)(diag)-169...
  • Page 479 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AP:DTC P0458 EVAPORATIVE EMISSION CONTROL SYSTEM PURGE CON- TROL VALVE CIRCUIT LOW • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 480 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OUTPUT SIGNAL FROM ECM. Is the voltage more than 10 V? Even if malfunction Go to step 2. 1)Turn the ignition switch to ON. indicator light 2)Measure the voltage between ECM and lights up, the cir- chassis ground.
  • Page 481 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POOR CONTACT. Is there poor contact in purge Repair poor con- Contact with SUB- Check poor contact in purge control solenoid control solenoid valve connec- tact in purge con- ARU distributor valve connector.
  • Page 482 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AQ:DTC P0459 EVAPORATIVE EMISSION CONTROL SYSTEM PURGE CON- TROL VALVE CIRCUIT HIGH • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 483 ECM chassis ground. connector. NOTE: Purge control solenoid valve operation can be executed using Subaru Select Monitor. For pro- cedure, refer to “Compulsory Valve Operation Check Mode”. <Ref. to EN(H4SO)(diag)-48, Compulsory Valve Operation Check Mode.> Connector & terminal (B134) No.
  • Page 484 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AR:DTC P0462 FUEL LEVEL SENSOR CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 485 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BATTERY No.13 SBF-4 SBF-1 IGNITION SWITCH 1 2 3 COMBINATION METER 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 B135 ECM 1 2 3...
  • Page 486 •Subaru Select Monitor temporary poor For detailed operation procedure, refer to the contact of the con- “READ CURRENT DATA FOR ENGINE”. nector may be the <Ref. to EN(H4SO)(diag)-32, Subaru Select cause. Monitor.> NOTE: In this case, repair the following: • Poor contact in...
  • Page 487 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check Is the resistance 0.5 — 2.5 Ω? Repair poor con- CHECK FUEL LEVEL SENSOR. Replace the fuel 1)Remove the fuel pump assembly. <Ref. to tact in harness level sensor. FU(H4SO)-57, Fuel Pump.>...
  • Page 488 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AS:DTC P0463 FUEL LEVEL SENSOR CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 489 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BATTERY No.13 SBF-4 SBF-1 IGNITION SWITCH 1 2 3 COMBINATION METER 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 B135 ECM 1 2 3...
  • Page 490 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 4.75 Go to step 3. Even if malfunction 1)Turn the ignition switch to ON. (Engine OFF) indicator light 2)Measure the voltage between ECM connec- lights up, the cir- tor and chassis ground.
  • Page 491 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK FUEL LEVEL SENSOR. Is the resistance more than Replace the fuel Replace the com- 54.5 Ω? 1)Remove the fuel pump assembly. <Ref. to level sensor. <Ref. bination meter. FU(H4SO)-57, Fuel Pump.>...
  • Page 492 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AT:DTC P0483 COOLING FAN RATIONALITY CHECK • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Occurrence of noise • Overheating CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 493 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) • WIRING DIAGRAM: BATTERY SBF-1 IGNITION SWITCH No.17 SBF-4 No.18 AIR CONDITIONING AIR CONDITIONING RELAY HOLDER RELAY HOLDER MAIN RELAY RELAY MAIN FAN SUB FAN MOTOR MOTOR B225 B134 ECM 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 B134 5 6 7...
  • Page 494 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect the rele- Check the radiator vant DTC using fan motor connec- “List of Diagnostic tor for connecting Trouble Code condition.
  • Page 495 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AV:DTC P0503 VEHICLE SPEED SENSOR INTERMITTENT/ERRATIC/HIGH • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>.
  • Page 496 CHECK TRANSMISSION TYPE. Is the target AT model? Go to step 2. Go to step 3. CHECK DTC P0720 ON DISPLAY. Does the Subaru Select Moni- Check front vehi- Go to step 3. tor or OBD-II general scan tool cle speed sensor indicate DTC P0720? signal circuit.
  • Page 497 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AW:DTC P0506 IDLE CONTROL SYSTEM RPM LOWER THAN EXPECTED • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Engine is difficult to start. • Engine does not start. •...
  • Page 498 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 499 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AX:DTC P0507 IDLE CONTROL SYSTEM RPM HIGHER THAN EXPECTED • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Engine keeps running at higher revolution than specified idling revolution. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 500 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 501 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AY:DTC P0512 STARTER REQUEST CIRCUIT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 502 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) • WIRING DIAGRAM: IGNITION SWITCH BATTERY SBF-4 SBF-1 : AT MODEL : MT MODEL : WITH SECURITY EXCEPT FOR AUSTRALIA MODEL : WITH SECURITY FOR AUSTRALIA MODEL AND WITHOUT SECURITY B323 INHIBITOR SWITCH STARTER MOTOR...
  • Page 503 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OPERATION OF STARTER MOTOR. Dose the starter motor oper- Repair battery Check starter Turn the ignition switch to ON. ate? short circuit in motor circuit. <Ref. starter motor cir- NOTE: cuit.
  • Page 504 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) AZ:DTC P0519 IDLE CONTROL SYSTEM MALFUNCTION (FAIL-SAFE) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine keeps running at higher revolution than specified idling revolution. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 505 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 506 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BB:DTC P0559 GENERATOR CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, Inspection Mode.>.
  • Page 507 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN GENERATOR Is the resistance more than 1 Go to step 2. Repair the ground AND ECM CONNECTOR. MΩ? short circuit in har- 1)Turn the ignition switch to OFF. ness between 2)Disconnect the connectors from generator ECM and purge...
  • Page 508 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BC:DTC P0562 SYSTEM VOLTAGE LOW • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Charge warning light comes on. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 509 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK GENERATOR. Is the voltage more than 10.8 Go to step 2. Repair the genera- 1)Start the engine. tor. <Ref. to 2)Idle after warm-up. SC(H4SO)-13, 3)Measure the voltage between generator B Generator.>...
  • Page 510 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BD:DTC P0563 SYSTEM VOLTAGE HIGH • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Charge warning light comes on. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 511 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK GENERATOR. Is the voltage less than 16.2 Go to step 2. Repair the genera- 1)Start the engine. tor. <Ref. to 2)Idle after warm-up. SC(H4SO)-13, 3)Measure the voltage between generator B Generator.>...
  • Page 512 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BE:DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY (RAM) ERROR • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Engine does not start. • Engine stalls. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 513 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check the rele- A temporary poor vant DTC using contact occurs. the List of Diag- nostic Trouble Code (DTC). <Ref. EN(H4SO)(diag)- 74, List of Diag- nostic Trouble...
  • Page 514 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BF:DTC P0691 COOLING FAN 1 CONTROL CIRCUIT LOW • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Radiator fan does not operate properly. • Overheating CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 515 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) • WIRING DIAGRAM: BATTERY SBF-1 IGNITION SWITCH No.17 SBF-4 No.18 AIR CONDITIONING AIR CONDITIONING RELAY HOLDER RELAY HOLDER MAIN RELAY RELAY MAIN FAN SUB FAN MOTOR MOTOR B225 B134 ECM 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 B134 5 6 7...
  • Page 516 4)While operating the radiator fan relay, mea- sure voltage between ECM terminal and ground. NOTE: Radiator fan relay operation can be executed using Subaru Select Monitor. For procedure, refer to “Compulsory Valve Operation Check Mode”. <Ref. to EN(H4SO)(diag)-32, Subaru Select Monitor.> Connector & terminal (B134) No.
  • Page 517 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BG:DTC P0692 COOLING FAN 1 CONTROL CIRCUIT HIGH • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Radiator fan does not operate properly. • Overheating CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 518 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) • WIRING DIAGRAM: BATTERY SBF-1 IGNITION SWITCH No.17 SBF-4 No.18 AIR CONDITIONING AIR CONDITIONING RELAY HOLDER RELAY HOLDER MAIN RELAY RELAY MAIN FAN SUB FAN MOTOR MOTOR B225 B134 ECM 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 B134 5 6 7...
  • Page 519 ECM connector. NOTE: Radiator fan relay operation can be executed using Subaru Select Monitor. For procedure, refer to “Compulsory Valve Operation Check Mode”. <Ref. to EN(H4SO)(diag)-48, Compul- sory Valve Operation Check Mode.> Connector & terminal (B134) No. 14 (+) — Chassis ground ( − − − − ): (B134) No.
  • Page 520 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BH:DTC P0703 TORQUE CONVERTER/BRAKE SWITCH “B” CIRCUIT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 521 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN TCM AND Is the resistance less than 1 Go to step 3. Repair or replace Ω? BRAKE LIGHT SWITCH CONNECTOR. the harness and 1)Disconnect the connectors from TCM and connector.
  • Page 522 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BI: DTC P0731 GEAR 1 INCORRECT RATIO NOTE: For the diagnostic procedure, refer to DTC P0734. <Ref. to EN(H4SO)(diag)-214, DTC P0734 GEAR 4 IN- CORRECT RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> BJ:DTC P0732 GEAR 2 INCORRECT RATIO NOTE: For the diagnostic procedure, refer to DTC P0734.
  • Page 523 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BL:DTC P0734 GEAR 4 INCORRECT RATIO • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Shift point too high or too low; engine brake not effected in “3” range; excessive shift shock; excessive tight corner “braking”...
  • Page 524 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BM:DTC P0741 TORQUE CONVERTER CLUTCH CIRCUIT PERFORMANCE OR STUCK OFF • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • No lock-up (after engine warm-up) • No shift or excessive tight corner “braking” CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 525 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ATF TEMPERATURE SENSOR CIR- Is there any trouble in ATF tem- Repair or replace Go to step 9. CUIT. perature sensor circuit? the ATF tempera- Check ATF temperature sensor circuit. <Ref. ture sensor circuit.
  • Page 526 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BN:DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 527 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC Go to step 2. P0705 using “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 528 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BO:DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW (AT VEHICLES) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 529 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 10 V? Go to step 2. Go to step 4. 1)Turn the ignition switch to ON. 2)Place the shift lever in neutral. 3)Measure the voltage between ECM and chassis ground.
  • Page 530 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BP:DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (AT MODEL) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 531 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OTHER DTC ON DISPLAY. Is any other DTC displayed? Inspect DTC using Go to step 2. “List of Diagnostic Trouble Code (DTC)”. <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble Code (DTC).>...
  • Page 532 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INHIBITOR SWITCH GROUND LINE. Is the resistance less than 5 Go to step 8. Repair open circuit Ω? Measure the resistance of harness between in harness inhibitor switch connector and engine ground. between inhibitor Connector &...
  • Page 533 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BQ:DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL) • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Erroneous idling CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 534 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage less than 1 V? Go to step 2. Go to step 4. 1)Turn the ignition switch to ON. 2)Set the shift lever to except neutral position. 3)Measure the voltage between ECM and chassis ground.
  • Page 535 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BR:DTC P0864 TCM COMMUNICATION CIRCUIT RANGE/PERFORMANCE • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 536 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ACCESSORY. Are car phone and/or CB Repair grounding Replace the TCM. installed on vehicle? line of car phone <Ref. to 4AT-74, or CB system. Transmission Con- trol Module (TCM).>...
  • Page 537 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BS:DTC P0865 TCM COMMUNICATION CIRCUIT LOW • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 538 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the voltage less than 1 V? Go to step 2. Even if malfunction TCM CONNECTOR. indicator light 1)Turn the ignition switch to ON. lights up, the cir- 2)Measure the voltage between ECM and cuit has returned...
  • Page 539 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BT:DTC P0866 TCM COMMUNICATION CIRCUIT HIGH • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 540 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the voltage more than 4 V? Go to step 5. Go to step 3. TCM CONNECTOR. Measure the voltage between ECM connector and chassis ground. Connector &...
  • Page 541 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BU:DTC P1110 ATMOSPHERIC PRESSURE SENSOR CIRCUIT MALFUNCTION (LOW INPUT) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 542 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BW:DTC P1134 A/F SENSOR MICRO-COMPUTER PROBLEM • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 543 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using Replace the ECM. the List of Diag- <Ref. to nostic Trouble FU(H4SO)-47, Code (DTC). <Ref. Engine Control Module (ECM).>...
  • Page 544 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BX:DTC P1137 O2 SENSOR CIRCUIT (LAMDA=1) (BANK1 SENSOR1) • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 545 If the engine is already warmed-up, operate at idle speed for at least 1 minute. 3)Read the data of front oxygen (A/F) sensor signal during idling using Subaru Select Moni- tor or OBD-II general scan tool. NOTE: •Subaru Select Monitor For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.
  • Page 546 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) BY:DTC P1492 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT) NOTE: For the diagnostic procedure, refer to DTC P1498. <Ref. to EN(H4SO)(diag)-238, DTC P1498 EGR SOLE- NOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>...
  • Page 547 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CE:DTC P1498 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Poor driving performance. • Engine breathing CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 548 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO EGR SOLE- Is the voltage more than 10 V? Go to step 2. Repair harness NOID VALVE. and connector. 1)Turn the ignition switch to OFF. NOTE: 2)Disconnect the connector from EGR sole- In this case, repair...
  • Page 549 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CF:DTC P1499 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Poor driving performance. • Engine breathing CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 550 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check the DTC Go to step 2. using the List of Diagnostic Trou- ble Code (DTC). <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble...
  • Page 551 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CG:DTC P1510 ISC SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT) NOTE: For the diagnostic procedure, refer to DTC P1516. <Ref. to EN(H4SO)(diag)-243, DTC P1516 ISC SOLE- NOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>...
  • Page 552 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CM:DTC P1516 ISC SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Engine breathing CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 553 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO IDLE AIR CON- Is the voltage more than 10 V? Go to step 2. Repair harness TROL SOLENOID VALVE. and connector. 1)Turn the ignition switch to OFF. NOTE: 2)Disconnect the connector from idle air con- In this case, repair...
  • Page 554 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CN:DTC P1517 ISC SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT) • DTC DETECTING CONDITION: • Immediately at fault recognition • TROUBLE SYMPTOM: • Erroneous idling • Engine stalls. • Engine breathing CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref.
  • Page 555 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check the DTC Go to step 2. using the List of Diagnostic Trou- ble Code (DTC). <Ref. to EN(H4SO)(diag)- 74, List of Diag- nostic Trouble...
  • Page 556 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CO:DTC P1518 STARTER SWITCH CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 557 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) • WIRING DIAGRAM: IGNITION SWITCH BATTERY SBF-4 SBF-1 : AT MODEL : MT MODEL : WITH SECURITY EXCEPT FOR AUSTRALIA MODEL : WITH SECURITY FOR AUSTRALIA MODEL AND WITHOUT SECURITY B323 INHIBITOR SWITCH STARTER MOTOR...
  • Page 558 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OPERATION OF STARTER MOTOR. Does the starter motor operate Repair harness Check starter Place the inhibitor switch in the “P” or “N” when ignition switch is turned and connector. motor circuit.
  • Page 559 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CP:DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION • DTC DETECTING CONDITION: • Immediately at fault recognition CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION, Inspection Mode.>.
  • Page 560 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 10 Repair ground Go to step 3. Ω? MAIN FUSE BOX CONNECTOR. short circuit in har- 1)Disconnect the negative terminal from bat- ness between tery, and then disconnect the positive terminal.
  • Page 561 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CQ:DTC P1698 ENGINE TORQUE CONTROL CUT SIGNAL CIRCUIT LOW INPUT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 562 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OUTPUT SIGNAL FROM ECM. Is the voltage more than 3 V? Repair poor con- Go to step 2. 1)Start the engine, and warm-up the engine. tact in ECM con- 2)Turn the ignition switch to OFF.
  • Page 563 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CR:DTC P1699 ENGINE TORQUE CONTROL CUT SIGNAL CIRCUIT HIGH INPUT • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 564 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OUTPUT SIGNAL FROM ECM. Is the voltage less than 3 V? Go to step 2. Repair battery 1)Start the engine, and warm-up the engine. short circuit in har- 2)Turn the ignition switch to OFF.
  • Page 565 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CS:DTC P1711 ENGINE TORQUE CONTROL SIGNAL 1 CIRCUIT MALFUNC- TION • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Excessive shift shock CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 566 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 4.5 V? Go to step 2. Go to step 4. 1)Turn the ignition switch to ON. 2)Measure the voltage between ECM and chassis ground.
  • Page 567 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) CT:DTC P1712 ENGINE TORQUE CONTROL SIGNAL 2 CIRCUIT MALFUNCTION • DTC DETECTING CONDITION: • Two consecutive driving cycles with fault • TROUBLE SYMPTOM: • Excessive shift shock CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47, OPERATION, Clear Memory Mode.>...
  • Page 568 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 4.5 V? Go to step 2. Go to step 4. 1)Turn the ignition switch to ON. 2)Measure the voltage between ECM and chassis ground.
  • Page 569 General Diagnostic Table ENGINE (DIAGNOSTICS) 20.General Diagnostic Table A: INSPECTION 1. ENGINE NOTE: Malfunction of parts other than those listed is also possible. <Ref. to ME(H4SO)-89, Engine Trouble in Gen- eral.> Symptom Problem parts 1) Idle air control solenoid valve 2) Manifold absolute pressure sensor 3) Intake air temperature sensor 4) Ignition parts (*1)

  • Page 570: Automatic Transmission

    General Diagnostic Table ENGINE (DIAGNOSTICS) Symptom Problem parts 1) Intake manifold pressure sensor 2) Intake air temperature sensor 3) Manifold absolute pressure sensor 4) Engine coolant temperature sensor (*2) 6. Surge 5) Crankshaft position sensor (*3) 6) Camshaft position sensor (*3) 7) Fuel injection parts (*4) 8) Throttle position sensor 9) Fuel pump and fuel pump relay...
  • Page 571 General Diagnostic Table ENGINE (DIAGNOSTICS) EN(H4SO)(diag)-262...
  • Page 572 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 573 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 574 FUEL INJECTION (FUEL SYSTEMS) FU(H4SOw/oOBD) Page General Description ..................2 Throttle Body.....................15 Intake Manifold..................16 Engine Coolant Temperature Sensor............28 Crankshaft Position Sensor...............29 Camshaft Position Sensor.................30 Knock Sensor....................31 Throttle Position Sensor................32 Intake Air Temperature and Manifold Absolute Pressure Sensor .....34 Idle Air Control Solenoid Valve ..............35 Fuel Injector ....................36 Oxygen Sensor ..................41 Engine Control Module (ECM) ..............43...
  • Page 575 General Description FUEL INJECTION (FUEL SYSTEMS) 1. General Description A: SPECIFICATIONS Model 1.6 L and 2.0 L 2.5 L 50 2 (13.2 US gal, 11.0 Imp gal) 60 2 (15.9 US gal, 13.2 Imp gal) Capacity Fuel tank Location Under rear seat Type Impeller Shutoff discharge pressure...
  • Page 576 General Description FUEL INJECTION (FUEL SYSTEMS) B: COMPONENT 1. INTAKE MANIFOLD (20) (23) (22) (13) (20) (14) (16) (10) (21) (15) (19) (18) (21) (11) (18) (12) (19) (17) (19) (18) FU-00906 FU(H4SOw/oOBD)-3...
  • Page 577 General Description FUEL INJECTION (FUEL SYSTEMS) Intake manifold gasket RH (12) Fuel pipe protector LH (22) Plug cord holder RH Fuel injector pipe (13) Intake air temperature and mani- (23) Accelerator cable bracket fold absolute pressure sensor Fuel injector O-ring (14) O-ring Tightening torque: N·m (kgf-m, ft-lb)
  • Page 578 General Description FUEL INJECTION (FUEL SYSTEMS) 2. AIR INTAKE SYSTEM FU-00907 Gasket Throttle body Tightening torque: N·m (kgf-m, ft-lb) Throttle position sensor T1: 1.6 (0.16, 1.2) Idle air control solenoid valve T2: 22 (2.2, 16.2) FU(H4SOw/oOBD)-5...
  • Page 579 General Description FUEL INJECTION (FUEL SYSTEMS) 3. CRANKSHAFT POSITION, CAMSHAFT POSITION AND KNOCK SENSORS FU-00414 Crankshaft position sensor Camshaft position sensor Tightening torque: N·m (kgf-m, ft-lb) Knock sensor Camshaft position sensor support T1: 6.4 (0.65, 4.7) T2: 24 (2.4, 17.4) FU(H4SOw/oOBD)-6...
  • Page 580 General Description FUEL INJECTION (FUEL SYSTEMS) 4. FUEL TANK • 1.6 L and 2.0 L MODEL (25) (16) (10) (11) (11) (11) (14) (13) (24) (24) (12) (11) (11) (15) (11) (17) (19) (18) (20) (11) (21) (11) (22) (18) (19) (11) (23)
  • Page 581 General Description FUEL INJECTION (FUEL SYSTEMS) Heat shield cover (11) Clip (21) Fuel pipe ASSY Fuel tank band (12) Evaporation hose B (22) Fuel return hose B Protector RH (13) Joint pipe (23) Evaporation hose E Fuel tank (14) Evaporation hose C (24) Evaporation hose F Fuel pump gasket...
  • Page 582 General Description FUEL INJECTION (FUEL SYSTEMS) • 2.5 L MODEL (30) (17) (10) (11) (12) (12) (12) (15) (14) (29) (13) (29) (12) (10) (12) (28) (16) (12) (12) (18) (21) (20) (22) (19) (27) (12) (12) (26) (23) (12) (24) (20) (12)
  • Page 583 General Description FUEL INJECTION (FUEL SYSTEMS) Heat shield cover (13) Evaporation hose B (25) Evaporation hose E Fuel tank band (14) Joint pipe (26) Fuel sub level sensor gasket Protector LH (15) Evaporation hose C (27) Jet pump filter Protector RH (16) Evaporation pipe ASSY (28)
  • Page 584 General Description FUEL INJECTION (FUEL SYSTEMS) 5. FUEL LINE (19) (18) (17) (24) (20) (16) (25) (15) (24) (22) (13) (21) (23) (14) (12) (1) (1) (10) (10) (11) FU-00910 FU(H4SOw/oOBD)-11...
  • Page 585 General Description FUEL INJECTION (FUEL SYSTEMS) Clip (11) Fuel pipe ASSY (21) Two-way valve drain hose A Fuel delivery hose A (12) Grommet (22) Connector Fuel filter bracket (13) Canister hose A (23) Two-way valve drain hose B Fuel filter holder (14) Canister (24)
  • Page 586 General Description FUEL INJECTION (FUEL SYSTEMS) 6. FUEL FILLER PIPE (11) (10) (12) FU-00956 Fuel filler pipe ASSY Air vent pipe holder Tightening torque: N·m (kgf-m, ft-lb) Evaporation hose holder Filler pipe packing T: 7.5 (0.76, 5.5) Clip Filler ring Clamp (10) Filler cap...
  • Page 587 TOOL NUMBER DESCRIPTION REMARKS 24082AA230 CARTRIDGE Troubleshooting for electrical system. ST24082AA230 22771AA030 SUBARU SELECT Troubleshooting for electrical systems. MONITOR KIT • English: 22771AA030 (Without printer) • German: 22771AA070 (Without printer) • French: 22771AA080 (Without printer) • Spanish: 22771AA090 (Without printer) ST22771AA030...
  • Page 588 Throttle Body FUEL INJECTION (FUEL SYSTEMS) 2. Throttle Body 7) Disconnect the engine coolant hoses from throt- tle body. A: REMOVAL 1) Disconnect the ground cable from battery. FU-00914 8) Remove the bolts which install the throttle body FU-00009 to intake manifold. 2) Remove the air cleaner case.
  • Page 589 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 3. Intake Manifold NOTE: Do not disconnect the power steering hose. A: REMOVAL 1) Release the fuel pressure. <Ref. to FU(H4SOw/ oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Open the fuel flap lid and remove the fuel filler cap.
  • Page 590 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) (7) Place the power steering pump and tank on 12) Remove the air cleaner case stay RH and en- right side wheel apron. gine harness bracket, and then disconnect the en- gine harness connectors from bulkhead harness connectors.
  • Page 591 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 16) Disconnect the connector from oil pressure 19) Remove the bolts which hold the intake mani- switch. fold onto cylinder heads. FU-00146 FU-00260 17) Disconnect the connector from camshaft posi- 20) Remove the intake manifold. tion sensor.
  • Page 592 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 3) Connect the connector to camshaft position sen- 7) Connect the connectors to engine coolant tem- sor. perature sensor. FU-00147 FU-00145 4) Connect the connector to oil pressure switch. 8) Install the air cleaner case stay RH and engine harness bracket, and then connect the engine har- ness connectors to bulkhead connectors.
  • Page 593 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 11) Connect the PCV hose to intake manifold. (3) Tighten the bolts which install the power steering pump on bracket. Tightening torque: 22 N·m (2.2 kgf-m, 16.2 ft-lb) FU-00141 12) Connect the spark plug cords to the spark plugs.
  • Page 594 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 17) Connect the connector to the fuel pump relay. 3) Remove the ignition coil & ignitor ASSY. FU-00916 FU-00918 18) Connect the battery ground cable to battery. 4) Disconnect the connector from intake air tem- perature and manifold absolute pressure sensor.
  • Page 595 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 8) Disconnect the pressure regulator vacuum hose 12) Disconnect the connector from purge control from intake manifold. solenoid valve. FU-00265 FU-00269 9) Remove the fuel pipe protector LH. 13) Disconnect the air by-pass hose from purge control solenoid valve.
  • Page 596 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 17) Remove the bolt which installs the fuel injector (2) Remove the fuel injector while lifting up the pipe on intake manifold as shown in the figure. fuel injector pipe. FU-00272 FU-00276 18) Remove the bolt which installs the fuel injector 21) Loosen the clamp which holds the fuel injector pipe LH on intake manifold.
  • Page 597 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 24) Remove the bolt which installs the fuel pipes on 2) Tighten the bolt which installs the fuel pipes on intake manifold. intake manifold. Tightening torque: 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) FU-00929 25) Remove the fuel pipe assembly (B) and pres- sure regulator (A) from intake manifold.
  • Page 598 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 6) Install the fuel injectors. 8) Tighten the two bolts which install the fuel pipes on intake manifold. NOTE: Always use new O-rings. Tightening torque: 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) ( A ) ( B ) ( A ) FU-00931...
  • Page 599 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 11) Connect the hoses to the purge control sole- 15) Install the fuel pipe protector RH. noid valve. Tightening torque: NOTE: 19 N·m (1.9 kgf-m, 14.0 ft-lb) Carefully connect the evaporation hoses. FU-00267 FU-00285 16) Install the fuel pipe protector LH.
  • Page 600 Intake Manifold FUEL INJECTION (FUEL SYSTEMS) 18) Install the throttle body to intake manifold. 23) Install the ignition coil & ignitor ASSY. NOTE: Replace the gasket with a new one. Tightening torque: 22 N·m (2.2 kgf-m, 16.2 ft-lb) FU-00918 24) Connect the connector to ignition coil & ignitor ASSY.

  • Page 601: Engine Coolant Temperature

    Engine Coolant Temperature Sensor FUEL INJECTION (FUEL SYSTEMS) 4. Engine Coolant Temperature Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the air intake duct and air cleaner case. <Ref. to IN(H4SO)-6, REMOVAL, Air Intake Duct.> and <Ref.
  • Page 602 Crankshaft Position Sensor FUEL INJECTION (FUEL SYSTEMS) 5. Crankshaft Position Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the bolt which installs the crankshaft position sensor to cylinder block. FU-00056 3) Remove the crankshaft position sensor, and then disconnect the connector from it.
  • Page 603 Camshaft Position Sensor FUEL INJECTION (FUEL SYSTEMS) 6. Camshaft Position Sensor 5) Remove the camshaft position sensor and cam- shaft position sensor support as a unit. A: REMOVAL 6) Remove the camshaft position sensor itself. 1) Disconnect the ground cable from battery. FU-00179 FU-00009 B: INSTALLATION...
  • Page 604 Knock Sensor FUEL INJECTION (FUEL SYSTEMS) 7. Knock Sensor B: INSTALLATION 1) Install the knock sensor to cylinder block. A: REMOVAL NOTE: 1) Disconnect the ground cable from battery. • For tightening torque, refer to “COMPONENT”. <Ref. to FU(H4SOw/oOBD)-3, COMPONENT, General Description.>...
  • Page 605 For tightening torque, refer to “COMPONENT”. FU-00290 <Ref. to FU(H4SOw/oOBD)-3, COMPONENT, B: INSTALLATION General Description.> 4) When using the Subaru Select Monitor; Install in the reverse order of removal. (1) Turn the ignition switch to OFF. NOTE: (2) Loosen the throttle position sensor holding For tightening torque, refer to “COMPONENT”.
  • Page 606 FU-00293 (4) Connect the Subaru Select Monitor to data link connector. FU-00933 5) Turn the ignition switch to ON, and Subaru Se- lect Monitor switch to ON. 6) Select the {2. Each System Check} in Main Menu. 7) Select the {Engine Control System} in Selection Menu.
  • Page 607 Intake Air Temperature and Manifold Absolute Pressure Sensor FUEL INJECTION (FUEL SYSTEMS) 9. Intake Air Temperature and 4) Remove the intake air temperature and manifold absolute pressure sensor. Manifold Absolute Pressure Sensor A: REMOVAL 1) Disconnect the ground cable from battery. FU-00936 B: INSTALLATION Install in the reverse order of removal.
  • Page 608 Idle Air Control Solenoid Valve FUEL INJECTION (FUEL SYSTEMS) 10.Idle Air Control Solenoid Valve A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Disconnect the connector from idle air control solenoid valve. FU-00937 3) Remove the idle air control solenoid valve from throttle body.
  • Page 609 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 610 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 611 FUEL INJECTION (FUEL SYSTEMS) FU(H4SOw/oOBD) Page General Description ..................2 Throttle Body.....................15 Intake Manifold..................16 Engine Coolant Temperature Sensor............28 Crankshaft Position Sensor...............29 Camshaft Position Sensor.................30 Knock Sensor....................31 Throttle Position Sensor................32 Intake Air Temperature and Manifold Absolute Pressure Sensor .....34 Idle Air Control Solenoid Valve ..............35 Fuel Injector ....................36 Oxygen Sensor ..................41 Engine Control Module (ECM) ..............43...
  • Page 612 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 11.Fuel Injector (3) Remove the bolts which install the power steering pump to bracket. A: REMOVAL 1. RH SIDE 1) Release the fuel pressure. <Ref. to FU(H4SOw/oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Open the fuel filler flap lid and remove the fuel filler cap.
  • Page 613 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 7) Remove the fuel pipe protector RH. (1) Remove the fuel injector securing clip. FU-00267 FU-00939 8) Disconnect the connector from fuel injector. (2) Remove the fuel injector while lifting up the fuel injector pipe. FU-00303 FU-00940 9) Remove the bolts which hold the fuel injector...
  • Page 614 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 2. LH SIDE 8) Move the washer tank, and secure it away from working area. 1) Release the fuel pressure. <Ref. to FU(H4SOw/ oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Open the fuel filler flap lid and remove the fuel filler cap.
  • Page 615 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) 12) Remove the bolt which installs the fuel injector (2) Remove the fuel injector while lifting up the pipe to intake manifold. fuel injector pipe. FU-00309 FU-00945 B: INSTALLATION 1. RH SIDE Install in the reverse order of removal. NOTE: Replace the O-rings with new ones.
  • Page 616 Fuel Injector FUEL INJECTION (FUEL SYSTEMS) Tightening torque: Tightening torque: 19 N·m (1.9 kgf-m, 14.0 ft-lb) 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) FU-00942 FU-00284 Tightening torque: Tightening torque: 19 N·m (1.9 kgf-m, 14.0 ft-lb) 6.4 N·m (0.65 kgf-m, 4.7 ft-lb) FU-00267 FU-00943 Tightening torque:...
  • Page 617 Oxygen Sensor FUEL INJECTION (FUEL SYSTEMS) 12.Oxygen Sensor B: INSTALLATION 1) Before installing the oxygen sensor, apply anti- A: REMOVAL seize compound only to the threaded portion of ox- 1) Disconnect the ground cable from battery. ygen sensor to make the next removal easier. Anti-seize compound: SS-30 by JET LUBE CAUTION:...
  • Page 618 Oxygen Sensor FUEL INJECTION (FUEL SYSTEMS) 5) Connect the battery ground cable to battery. FU-00009 FU(H4SOw/oOBD)-42...
  • Page 619 Engine Control Module (ECM) FUEL INJECTION (FUEL SYSTEMS) 13.Engine Control Module (ECM) B: INSTALLATION Install in the reverse order of removal. A: REMOVAL CAUTION: 1) Disconnect the ground cable from battery. When replacing the ECM, be careful not to use the wrong spec.
  • Page 620 Main Relay FUEL INJECTION (FUEL SYSTEMS) 14.Main Relay A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the front side sill cover of passenger side. 3) Remove the bolt which holds the main relay bracket on body. 4) Disconnect the connectors from main relay.
  • Page 621 Fuel Pump Relay FUEL INJECTION (FUEL SYSTEMS) 15.Fuel Pump Relay A: REMOVAL 1) Disconnect the ground cable from battery. FU-00009 2) Remove the front side sill cover of passenger side. 3) Remove the bolt which holds the fuel pump relay bracket on body.
  • Page 622 Fuel FUEL INJECTION (FUEL SYSTEMS) 16.Fuel 5) Drain fuel from fuel tank. Set a container under the vehicle and remove the A: OPERATION drain plug from fuel tank. • 1.6 L and 2.0 L MODEL 1. RELEASING OF FUEL PRESSURE WARNING: •...
  • Page 623 Fuel Tank FUEL INJECTION (FUEL SYSTEMS) 17.Fuel Tank 9) Loosen the clamp and disconnect the fuel filler hose and air vent hose from fuel filler pipe. A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel on floor. 1) Set the vehicle on a lift.
  • Page 624 Fuel Tank FUEL INJECTION (FUEL SYSTEMS) B: INSTALLATION 5) Connect the fuel hoses, and then secure them with clips quick connector. <Ref. 1) Support the fuel tank with transmission jack and FU(H4SOw/oOBD)-63, INSTALLATION, Fuel De- push the fuel tank harness into access hole with livery, Return and Evaporation Lines.>...
  • Page 625 Fuel Tank FUEL INJECTION (FUEL SYSTEMS) 10) Connect the connector to the fuel pump relay. FU-00916 C: INSPECTION 1) Make sure there are no cracks, holes or other damage on fuel tank. 2) Make sure the fuel hoses and fuel pipes are not cracked and the connections are tightened firmly.
  • Page 626 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 18.Fuel Filler Pipe 9) Drain fuel from the fuel tank. Set a container un- der the vehicle and remove the drain plug from fuel A: REMOVAL tank. • 1.6 L and 2.0 L MODEL WARNING: •...
  • Page 627 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 12) Separate the evaporation hoses from clip of 17) Remove the fuel filler pipe to under side of ve- fuel filler pipe. hicle. 18) Remove the air vent pipe together with clip from body. FU-00098 13) Disconnect the air vent hose from fuel filler FU-00102...
  • Page 628 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 5) Connect the air vent hose to the fuel filler pipe. 8) Tighten the bolt which holds the fuel filler pipe bracket on body. Tightening torque: 7.4 N·m (0.75 kgf-m, 5.4 ft-lb) FU-00099 6) Insert the fuel filler hose (A) approx.
  • Page 629 Fuel Filler Pipe FUEL INJECTION (FUEL SYSTEMS) 12) Lower the vehicle. 13) Tighten the wheel nuts. 14) Connect the connector to the fuel pump relay. FU-00916 15) Connect the battery ground cable to battery. FU-00009 FU(H4SOw/oOBD)-53...
  • Page 630 Fuel Pump FUEL INJECTION (FUEL SYSTEMS) 19.Fuel Pump 8) Remove the access hole lid. A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel on floor. NOTE: Fuel pump assembly consists of fuel pump and fuel level sensor.
  • Page 631 Fuel Pump FUEL INJECTION (FUEL SYSTEMS) • 2.5 L MODEL 9) Disconnect the connector from fuel pump. 1) Release the fuel pressure. <Ref. to FU(H4SOw/ oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Open the fuel filler flap lid and remove the fuel filler cap.
  • Page 632 Fuel Pump FUEL INJECTION (FUEL SYSTEMS) B: INSTALLATION C: INSPECTION Install in the reverse order of removal. Do the fol- Connect the lead harness to connector terminal of lowing: fuel pump and apply battery power supply to check whether the pump operates. NOTE: WARNING: Always use new gaskets.
  • Page 633 Fuel Level Sensor FUEL INJECTION (FUEL SYSTEMS) 20.Fuel Level Sensor 3) Remove the bolt which installs the fuel level sen- sor on mounting bracket. A: REMOVAL • 1.6 L and 2.0 L MODEL WARNING: • Place “NO FIRE” signs near working area. •...
  • Page 634 Fuel Sub Level Sensor FUEL INJECTION (FUEL SYSTEMS) 21.Fuel Sub Level Sensor 8) Disconnect the fuel jet pump hose. A: REMOVAL NOTE: Fuel sub level sensor is equipped to only 2.5 L model. WARNING: • Place “NO FIRE” signs near working area. •...
  • Page 635 Fuel Filter FUEL INJECTION (FUEL SYSTEMS) 22.Fuel Filter A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel on floor. 1) Release the fuel pressure. <Ref. to FU(H4SOw/ oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.>...
  • Page 636 Fuel Cut Valve FUEL INJECTION (FUEL SYSTEMS) 23.Fuel Cut Valve A: REMOVAL WARNING: • Place “NO FIRE” signs near working area. • Be careful not to spill fuel on floor. 1) Remove the fuel tank. <Ref. to FU(H4SOw/ oOBD)-47, REMOVAL, Fuel Tank.> 2) Move the clip and disconnect the evaporation hose from fuel cut valve.
  • Page 637 Fuel Damper Valve FUEL INJECTION (FUEL SYSTEMS) 24.Fuel Damper Valve A: REMOVAL 1) Release the fuel pressure. <Ref. to FU(H4SOw/ oOBD)-46, RELEASING OF FUEL PRESSURE, OPERATION, Fuel.> 2) Remove the fuel damper valve from fuel return line. FU-00121 B: INSTALLATION Install in the reverse order of removal.
  • Page 638 Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) 25.Fuel Delivery, Return and Evaporation Lines A: REMOVAL 1) Set the vehicle on a lift. 2) Release the fuel pressure. <Ref. to FU(H4SOw/oOBD)-46, RELEASING OF FUEL PRESSURE, OPER- ATION, Fuel.> 3) Open the fuel filler flap lid and remove the fuel filler cap.
  • Page 639 Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) 9) Separate the quick connector on fuel delivery (1) Set the new retainer (B) to connector (A). line. (2) Push the pipe into connector completely. (1) Clean the pipe and connector, if they are NOTE: covered with dust.
  • Page 640 Fuel Delivery, Return and Evaporation Lines FUEL INJECTION (FUEL SYSTEMS) 2) Connect the fuel delivery hose to pipe with an overlap of 20 to 25 mm (0.79 to 0.98 in). Type A: When the fitting length is specified. Type B: When the fitting length is not specified. 2: 2.5 ±...
  • Page 641 Fuel System Trouble in General FUEL INJECTION (FUEL SYSTEMS) 26.Fuel System Trouble in General A: INSPECTION Trouble and possible cause Corrective action 1. Insufficient fuel supply to injector Fuel pump will not operate. Inspect connections, especially ground, and tighten ❍ Defective terminal contact. securely.
  • Page 642 Fuel System Trouble in General FUEL INJECTION (FUEL SYSTEMS) FU(H4SOw/oOBD)-66...
  • Page 643 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 644 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 645 EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) EC(H4SOw/oOBD) Page General Description ..................2 Front Catalytic Converter ................3 Rear Catalytic Converter................4 Canister.......................5 Purge Control Solenoid Valve ..............6 Two-way Valve....................7...
  • Page 646 General Description EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 1. General Description A: CAUTION • Wear working clothing, including a cap, protec- tive goggles, and protective shoes during opera- tion. • Remove contamination including dirt and corro- sion before removal, installation or disassembly. •...
  • Page 647 Front Catalytic Converter EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 2. Front Catalytic Converter A: REMOVAL The front catalytic converter and center exhaust pipe are integrated into one unit. Therefore, the re- moval procedures are the same as those for center exhaust pipe.
  • Page 648 Rear Catalytic Converter EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 3. Rear Catalytic Converter A: REMOVAL The rear catalytic converter and center exhaust pipe are integrated into one unit. Therefore, the re- moval procedures are the same as those for center exhaust pipe.
  • Page 649 Canister EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 4. Canister A: REMOVAL 1) Lift-up the vehicle. 2) Loosen the two clamps which hold the two can- ister hoses, and then disconnect the three evapo- ration hoses from canister. EC-00012 3) Remove the canister from body. EC-00013 B: INSTALLATION Install in the reverse order of removal.
  • Page 650 Purge Control Solenoid Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 5. Purge Control Solenoid Valve B: INSTALLATION Install in the reverse order of removal. A: REMOVAL Tightening torque: 1) Disconnect the ground cable from battery. 19 N·m (1.9 kgf-m, 13.7 ft-lb) FU-00009 EC-00014 2) Disconnect the connector and hose of purge...
  • Page 651 Two-way Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) 6. Two-way Valve A: REMOVAL 1) Lift-up the vehicle. 2) Remove the canister from body. <Ref. to EC(H4SOw/oOBD)-5, REMOVAL, Canister.> 3) Remove the two-way valve with bracket as a sin- gle unit from body. EC-00016 4) Remove the two-way valve from bracket.
  • Page 652 Two-way Valve EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) EC(H4SOw/oOBD)-8...
  • Page 653 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 654 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 655 INTAKE (INDUCTION) IN(H4SOw/oOBD) Page General Description ..................2...
  • Page 656 General Description INTAKE (INDUCTION) 1. General Description A: SPECIFICATIONS Specification of model without OBD is included in IN(H4SO) section. <Ref. to IN(H4SO)-2, General Description.> IN(H4SOw/oOBD)-2...
  • Page 657 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 658 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 659 MECHANICAL ME(H4SOw/oOBD) Page General Description ..................2...
  • Page 660 General Description MECHANICAL 1. General Description A: SPECIFICATIONS Specification of model without OBD is the same as that of model with OBD. <Ref. to ME(H4SO)-2, General Description.> ME(H4SOw/oOBD)-2...
  • Page 661 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 662 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 663 EXHAUST EX(H4SOw/oOBD) Page General Description ..................2 Front Exhaust Pipe..................6 Center Exhaust Pipe ...................9 Rear Exhaust Pipe ..................10 Muffler .......................11...
  • Page 664 General Description EXHAUST 1. General Description A: COMPONENT 1. WITH CATALYTIC CONVERTER (16) (15) (13) (14) (16) (11) (10) (17) (16) (27) (18) (28) (23) (19) (26) (25) (24) (12) (30) (20) (29) (22) (21) (12) EX-00150 EX(H4SOw/oOBD)-2...
  • Page 665 General Description EXHAUST Front exhaust pipe upper cover (15) Muffler (28) Rear catalytic converter upper cover Front exhaust pipe lower cover (16) Cushion rubber Clamp (17) Rear exhaust pipe (29) Rear catalytic converter lower cover Front exhaust pipe upper cover LH (18) Lower clamp Front exhaust pipe lower cover LH...
  • Page 666 General Description EXHAUST 2. WITHOUT CATALYTIC CONVERTER (16) (15) (13) (14) (16) (11) (10) (24) (16) (12) (23) (17) (18) (22) (21) (25) (20) (19) (25) EX-00151 EX(H4SOw/oOBD)-4...
  • Page 667 General Description EXHAUST Front exhaust pipe upper cover (12) Rear exhaust pipe cover (23) Center exhaust pipe upper cover Front exhaust pipe lower cover (13) Gasket (24) Rear exhaust pipe Clamp (14) Self-locking nut (25) Gasket Front exhaust pipe upper cover LH (15) Muffler Front exhaust pipe lower cover LH...
  • Page 668 Front Exhaust Pipe EXHAUST 2. Front Exhaust Pipe 6) Remove the nuts which hold the front exhaust pipe onto cylinder heads. A: REMOVAL CAUTION: 1) Disconnect the ground cable from battery. Be careful not to pull down the front and center exhaust pipe assembly.
  • Page 669 Front Exhaust Pipe EXHAUST B: INSTALLATION 7) Tighten the bolts which install the front and cen- ter exhaust pipe assembly to rear exhaust pipe. 1) Install the oxygen sensor. (With catalytic con- verter) <Ref. to FU(H4SOw/oOBD)-41, INSTALLA- Tightening torque: TION, Oxygen Sensor.> 18 N·m (1.8 kgf-m, 13.3 ft-lb) 2) Install the front exhaust pipe to center exhaust pipe.
  • Page 670 Front Exhaust Pipe EXHAUST 11) Connect the battery ground cable to battery. FU-00009 C: INSPECTION 1) Make sure there are no exhaust leaks from con- nections and welds. 2) Make sure there are no holes or rusting. EX(H4SOw/oOBD)-8...
  • Page 671 Center Exhaust Pipe EXHAUST 3. Center Exhaust Pipe A: REMOVAL After removing the center and front exhaust pipes as one unit, separate them. Refer to the procedure for removing the front exhaust pipe. <Ref. to EX(H4SOw/oOBD)-6, REMOVAL, Front Exhaust Pipe.> B: INSTALLATION Install the center exhaust pipe and front exhaust pipe as one unit.
  • Page 672 Rear Exhaust Pipe EXHAUST 4. Rear Exhaust Pipe 2) Install the rear exhaust pipe bracket to cushion rubber. A: REMOVAL 1) Separate the rear exhaust pipe from center ex- haust pipe. CAUTION: Be careful, the exhaust pipe is hot. EX-00126 NOTE: Replace the gaskets with new ones.
  • Page 673 Muffler EXHAUST 5. Muffler 3) Make sure the cushion rubber is not worn or cracked. A: REMOVAL 1) Separate the muffler from rear exhaust pipe. CAUTION: Be careful, the exhaust pipe is hot. EX-00024 2) Apply a coat of spray type lubricant to the mating area of cushion rubbers in advance.
  • Page 674 Muffler EXHAUST EX(H4SOw/oOBD)-12...
  • Page 675 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 676 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 677 COOLING CO(H4SOw/oOBD) Page General Description ..................2...
  • Page 678 General Description COOLING 1. General Description A: SPECIFICATIONS Specification of model without OBD is the same as that of model with OBD. <Ref. to CO(H4SO)-2, General Description.> CO(H4SOw/oOBD)-2...
  • Page 679 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 680 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 681 LUBRICATION LU(H4SOw/oOBD) Page General Description ..................2...
  • Page 682 General Description LUBRICATION 1. General Description A: SPECIFICATIONS Specification of model without OBD is the same as that of model with OBD. <Ref. to LU(H4SO)-2, General Description.> LU(H4SOw/oOBD)-2...
  • Page 683 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 684 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 685 SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) Page General Description ..................2...
  • Page 686 General Description SPEED CONTROL SYSTEMS 1. General Description A: SPECIFICATION Specification of model without OBD is the same as that of model with OBD. <Ref. to SP(H4SO)-2, General Description.> SP(H4SOw/oOBD)-2...
  • Page 687 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 688 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 689 IGNITION IG(H4SOw/oOBD) Page General Description ..................2...
  • Page 690 General Description IGNITION 1. General Description A: SPECIFICATIONS Specifications for model without OBD is included in IG(H4SO) section. <Ref. to IG(H4SO)-2, General Description.> IG(H4SOw/oOBD)-2...
  • Page 691 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 692 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 693 STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) Page General Description ..................2...
  • Page 694 General Description STARTING/CHARGING SYSTEMS 1. General Description A: SPECIFICATIONS Specification of model without OBD is included in SC(H4SO) section. <Ref. to SC(H4SO)-2, General Description.> SC(H4SOw/oOBD)-2...
  • Page 695 EC(H4SO) (AUX. EMISSION CONTROL DEVICES) INTAKE (INDUCTION) IN(H4SO) MECHANICAL ME(H4SO) This service manual has been prepared to provide SUBARU service personnel EXHAUST EX(H4SO) with the necessary information and data for the correct maintenance and repair of SUBARU vehicles. COOLING CO(H4SO)
  • Page 696 2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX ENGINE SECTION 1 LUBRICATION LU(H4SOw/oOBD) SPEED CONTROL SYSTEMS SP(H4SOw/oOBD) IGNITION IG(H4SOw/oOBD) STARTING/CHARGING SYSTEMS SC(H4SOw/oOBD) EN(H4SOw/oOBD) ENGINE (DIAGNOSTICS) (diag) G1870GE2...
  • Page 697 Basic Diagnostic Procedure ................2 Check List for Interview................4 General Description ..................6 Electrical Components Location..............9 Engine Control Module (ECM) I/O Signal ..........17 Subaru Select Monitor................20 Read Diagnostic Trouble Code (DTC) ............24 Inspection Mode..................26 Clear Memory Mode..................28 Compulsory Valve Operation Check Mode ..........29 Malfunction Indicator Light ................30...
  • Page 698 Record the DTC. Repair the related 1)Turn the ignition switch to OFF. Monitor indicate DTC? <Ref. to Repair the trouble parts. 2)Connect the SUBARU Select Monitor to data EN(H4SOw/oOBD)(diag)-55, cause. <Ref. to NOTE: link connector. LIST, List of Diagnostic Trou-...
  • Page 699 Basic Diagnostic Procedure ENGINE (DIAGNOSTICS) 2. WITHOUT SUBARU SELECT MONITOR CAUTION: • Check the connector while it is connected unless specified otherwise. • Be sure to check again from the beginning in order to prevent secondary trouble caused by repair work.
  • Page 700 Check List for Interview ENGINE (DIAGNOSTICS) 2. Check List for Interview A: CHECK 1. CHECK LIST No. 1 Check the following items when problem has occurred. NOTE: Use copies of this page for interviewing customers. Customer’s name Engine No. Date of sale Fuel brand Date of repair Odometer reading...
  • Page 701 Check List for Interview ENGINE (DIAGNOSTICS) 2. CHECK LIST No. 2 Check the following items about the vehicle’s state when the malfunction indicator light turns on. NOTE: Use copies of this page for interviewing customers. a) Other warning lights or indicators turn on. ❏ Yes / ❏ No ❏...
  • Page 702 General Description ENGINE (DIAGNOSTICS) 3. General Description 8) Use the ECM mounting stud bolt at the body head grounding points when measuring voltage A: CAUTION and resistance inside the passenger compartment. 1) Airbag system wiring harness is routed near en- gine control module (ECM), main relay and fuel pump relay.
  • Page 703 General Description ENGINE (DIAGNOSTICS) 12) Observe the following cautions when installing 2) Check the condition of the main and other fuses, a radio in MFI equipped models. and harnesses and connectors. Also check for proper grounding. CAUTION: • The antenna must be kept as far apart as pos- 2.
  • Page 704 TOOL NUMBER DESCRIPTION REMARKS 24082AA230 CARTRIDGE Troubleshooting for electrical systems. ST24082AA230 22771AA030 SUBARU SELECT Troubleshooting for electrical systems. MONITOR KIT • English: 22771AA030 (Without printer) • German: 22771AA070 (Without printer) • French: 22771AA080 (Without printer) • Spanish: 22771AA090 (Without printer) ST22771AA030...
  • Page 705 Electrical Components Location ENGINE (DIAGNOSTICS) 4. Electrical Components Location A: LOCATION 1. MODULE EN-01515 EN-01516 Engine control module (ECM) Read memory connector Data link connector Malfunction indicator light Test mode connector EN(H4SOw/oOBD)(diag)-9...
  • Page 706 Electrical Components Location ENGINE (DIAGNOSTICS) EN-00156 EN-01517 EN-01518 EN-01519 EN(H4SOw/oOBD)(diag)-10...
  • Page 707 Electrical Components Location ENGINE (DIAGNOSTICS) 2. SENSOR EN-01520 Engine coolant temperature sen- Throttle position sensor Vehicle speed sensor Knock sensor Intake air temperature and Mani- Crankshaft position sensor fold absolute pressure sensor Camshaft position sensor EN(H4SOw/oOBD)(diag)-11...
  • Page 708 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01521 EN-01522 EN-01523 EN-01524 EN-01526 EN-01525 EN-01527 EN(H4SOw/oOBD)(diag)-12...
  • Page 709 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01528 Oxygen sensor (With catalyst con- verter model) EN-01529 EN(H4SOw/oOBD)(diag)-13...
  • Page 710 Electrical Components Location ENGINE (DIAGNOSTICS) 3. SOLENOID VALVE, EMISSION CONTROL SYSTEM PARTS AND IGNITION SYSTEM PARTS EN-01530 Purge control solenoid valve Ignition coil and ignitor ASSY CO resistor (Without catalyst con- verter model) Idle air control solenoid valve EN(H4SOw/oOBD)(diag)-14...
  • Page 711 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01531 EN-01532 EN-01534 EN-01533 EN-01535 EN(H4SOw/oOBD)(diag)-15...
  • Page 712 Electrical Components Location ENGINE (DIAGNOSTICS) EN-01536 Fuel pump Main relay Fuel pump relay EN-01537 EN-01538 EN-01539 EN(H4SOw/oOBD)(diag)-16...
  • Page 713 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) 5. Engine Control Module (ECM) I/O Signal A: ELECTRICAL SPECIFICATION B134 B135 B136 25 24 26 25 26 25 24 EN-01540 EN(H4SOw/oOBD)(diag)-17...
  • Page 714 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) Signal (V) Connec- Terminal Content Ignition SW Note Engine ON tor No. (Idling) ON (Engine OFF) ±6 Signal (+) B135 Sensor output waveform Crankshaft position Signal (−) B135 — sensor Shield B135 —...
  • Page 715 Engine Control Module (ECM) I/O Signal ENGINE (DIAGNOSTICS) Signal (V) Connec- Terminal Content Ignition SW Note tor No. Engine ON (Idling) ON (Engine OFF) Signal 1 B134 — 1 — 13 Waveform Idle air con- Signal 2 B134 — 1 — 13 Waveform trol sole- Signal 3...
  • Page 716 1. HOW TO USE SUBARU SELECT MONI- 1) Prepare the SUBARU Select Monitor kit. EN-00040 (A) Power switch 6) Using the SUBARU Select Monitor, call up any DTCs and various data, then record them. EN-00038 2. READ DIAGNOSTIC TROUBLE CODE 2) Connect the diagnosis cable to SUBARU Select (DTC) FOR ENGINE.
  • Page 717 Subaru Select Monitor ENGINE (DIAGNOSTICS) 3. READ CURRENT DATA SHOWN ON DISPLAY. 1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key. 2) On the «System Selection Menu» display screen, select the {Engine Control System} and press the [YES] key.
  • Page 718 ON or OFF Canister Purge Control Canister purge control solenoid valve — ON or OFF Solenoid Valve *1: With catalyst model only *2: Without catalyst model only NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SOw/oOBD)(diag)-22...
  • Page 719 *1: On MT model, switch is turned ON when gear position is in neutral position. On AT model, switch is turned ON when shift position is in “P” or “N” position. *2: With catalyst model only NOTE: For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. EN(H4SOw/oOBD)(diag)-23...
  • Page 720 5) On the «DTC Display» display screen, select the {Current DTC} or {History DTC} and press the [YES] key. NOTE: • For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MANUAL. • For detailed concerning DTCs, refer to the List of DTC. <Ref. to EN(H4SOw/oOBD)(diag)-55, LIST, List of Diagnostic Trouble Code (DTC).>...
  • Page 721 Read Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) The malfunction indicator light flashes code corresponding to faulty parts. The long segment (1.3 seconds ON) indicates a “ten”, and the short segment (0.2 seconds ON) signifies “one”. And middle segment (0.5 sec- onds ON) means OK code.
  • Page 722 (A) Test mode connector this may cause vehicle to jump off free rollers. 2) Connect the SUBARU Select Monitor to data link • In order to prevent the vehicle from slipping connector. <Ref. to EN(H4SOw/oOBD)(diag)-9, due to vibration, do not place any wooden LOCATION, Electrical Components Location.>...
  • Page 723 • If trouble still remains in the memory, the corre- sponding DTC appears on the display screen. NOTE: • For detailed operation procedure, refer to the SUBARU SELECT MONITOR OPERATION MAN- UAL. • For detailed concerning DTCs, refer to the DTC LIST. <Ref. to EN(H4SOw/oOBD)(diag)-55, LIST, List of Diagnostic Trouble Code (DTC).>...
  • Page 724 4) On the «Engine Diagnosis» display screen, select the {Clear Memory} and press the [YES] key. 5) When the “Done” and “Turn Ignition Switch OFF” are shown on the display screen, turn the SUBARU Se- lect Monitor and ignition switch to OFF.
  • Page 725 Compulsory Valve Operation Check Mode ENGINE (DIAGNOSTICS) 10.Compulsory Valve Operation Check Mode A: OPERATION 1) Connect the test mode connector at the lower portion of instrument panel (on the driver’s side). EN-01542 (A) Test mode connector 2) Each valve functions when the ignition switch is turned to ON (engine OFF).
  • Page 726 Malfunction Indicator Light ENGINE (DIAGNOSTICS) 11.Malfunction Indicator Light A: PROCEDURE 1. Activation of malfunction indicator light. <Ref. to EN(H4SOw/oOBD)(diag)-30, ACTIVATION OF MALFUNCTION INDICA- TOR LIGHT, Malfunction Indicator Light.> ↓ 2. Malfunction indicator light does not come on. <Ref. to EN(H4SOw/oOBD)(diag)-32, MALFUNCTION INDICATOR LIGHT DOES NOT COME ON., Malfunction Indicator Light.>...
  • Page 727 Malfunction Indicator Light ENGINE (DIAGNOSTICS) 3) When the ignition switch is turned to ON (engine off) or to START with the test mode connector con- nected, the malfunction indicator light blinks at a cycle of 3 Hz. EN-01545 (A) Malfunction indicator light when no trouble (1) ON (2) OFF (3) 1 sec.
  • Page 728 Malfunction Indicator Light ENGINE (DIAGNOSTICS) C: MALFUNCTION INDICATOR LIGHT DOES NOT COME ON. • DIAGNOSIS: • The malfunction indicator light circuit is open or shorted. • TROUBLE SYMPTOM: • When the ignition switch is turned ON (engine OFF), the malfunction indicator light does not come on. •...
  • Page 729 Malfunction Indicator Light ENGINE (DIAGNOSTICS) Step Check CHECK ECM CONNECTOR. Is the ECM connector correctly Replace the ECM. Repair the con- connected? nection of ECM connector. CHECK HARNESS BETWEEN COMBINA- Is the resistance less than 1 Go to step 5. Repair the har- Ω? TION METER AND ECM CONNECTOR.
  • Page 730 • The malfunction indicator light circuit is shorted. • TROUBLE SYMPTOM: • Although the malfunction indicator light comes on when engine runs, but DTC is not shown on SUBARU Select Monitor or OBD-II general scan tool display. • WIRING DIAGRAM:...
  • Page 731 Malfunction Indicator Light ENGINE (DIAGNOSTICS) E: MALFUNCTION INDICATOR LIGHT DOES NOT BLINK AT A CYCLE OF 3 HZ. • DIAGNOSIS: • The malfunction indicator light circuit is open or shorted. • Test mode connector circuit is in open. • TROUBLE SYMPTOM: •...
  • Page 732 Malfunction Indicator Light ENGINE (DIAGNOSTICS) Step Check CHECK STATUS OF MALFUNCTION INDI- Does the malfunction indicator Go to step 2. Repair the mal- CATOR LIGHT. light come on? function indicator 1)Turn the ignition switch to OFF. light circuit. <Ref. 2)Disconnect the test mode connector at lower to EN(H4SOw/ portion of instrument panel (on driver’s side).
  • Page 733 Malfunction Indicator Light ENGINE (DIAGNOSTICS) F: MALFUNCTION INDICATOR LIGHT REMAINS BLINKING AT A CYCLE OF 3 • DIAGNOSIS: • Test mode connector circuit is shorted. • TROUBLE SYMPTOM: • Even though test mode connector is disconnected, the malfunction indicator light blinks at a cycle of 3 Hz when ignition switch is turned to ON.
  • Page 734 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) 12.Diagnostics for Engine Starting Failure A: PROCEDURE 1. Inspection of starter motor circuit. <Ref. to EN(H4SOw/oOBD)(diag)-39, STARTER MOTOR CIRCUIT, Diagnostics for Engine Starting Failure.> ↓ 2. Inspection of ECM power supply and ground line. <Ref. to EN(H4SOw/oOBD)(diag)-42, ENGINE CONTROL MODULE (ECM) POWER SUPPLY AND GROUND LINE, Diagnostics for Engine Starting Failure.>...
  • Page 735 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) B: STARTER MOTOR CIRCUIT CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.> and <Ref. to EN(H4SOw/oOBD)(di- ag)-26, OPERATION, Inspection Mode.> •...
  • Page 736 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR STARTER MO- Is the voltage more than 10 V? Go to step 4. Go to step 5. TOR. 1)Turn the ignition switch to OFF. 2)Disconnect the connector from starter motor. 3)Turn the ignition switch to START.
  • Page 737 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK INHIBITOR SWITCH CIRCUIT. Is the resistance less than 1 Repair the open Go to step 11. Ω? 1)Turn the ignition switch to OFF. circuit in harness 2)Place the selector lever in the “P” or “N” posi- between starter tion.
  • Page 738 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) C: ENGINE CONTROL MODULE (ECM) POWER SUPPLY AND GROUND LINE CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.> and <Ref. to EN(H4SOw/oOBD)(di- ag)-26, OPERATION, Inspection Mode.>...
  • Page 739 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK MAIN RELAY. Is the resistance less than 10 Go to step 2. Replace the main Ω? 1)Turn the ignition switch to OFF. relay. 2)Remove the main relay. 3)Connect the battery to main relay terminals No.
  • Page 740 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK GROUND CIRCUIT OF MAIN RE- Is the resistance less than 5 Go to step 9. Repair the open Ω? LAY. circuit between 1)Turn the ignition switch to OFF. main relay and 2)Measure the resistance between main relay chassis ground.
  • Page 741 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) D: IGNITION CONTROL SYSTEM CAUTION: After repair or replacement of the faulty parts, conduct the Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.> and <Ref. to EN(H4SOw/ oOBD)(diag)-26, OPERATION, Inspection Mode.> •...
  • Page 742 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK IGNITION SYSTEM FOR SPARKS. Does spark occur at each cyl- Check the fuel Go to step 2. 1)Remove the plug cord cap from each spark inder? pump system. plug. <Ref. to 2)Install new spark plug on the plug cord cap.
  • Page 743 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR IGNITION COIL Is the voltage more than 10 V? Go to step 7. Replace the igni- & IGNITOR ASSY. tion coil & ignitor Check if the voltage varies synchronously with ASSY.
  • Page 744 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND IG- Is the resistance less than 1 Go to step 11. Repair the har- Ω? NITION COIL & IGNITOR ASSY CONNEC- ness and connec- TOR. tor. Measure the resistance of harness between NOTE: ECM and ignition coil &...
  • Page 745 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) E: FUEL PUMP CIRCUIT CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.> and <Ref. to EN(H4SOw/oOBD)(di- ag)-26, OPERATION, Inspection Mode.> •...
  • Page 746 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK OPERATING SOUND OF FUEL Does the fuel pump produce Check the fuel Go to step 2. PUMP. operating sound? injector circuit. Make sure that the fuel pump is in operation for <Ref.
  • Page 747 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK FUEL PUMP RELAY. Is the resistance less than 10 Go to step 7. Replace the fuel Ω? 1)Disconnect the connector from fuel pump pump relay. relay. 2)Remove the fuel pump relay from bracket. 3)Connect the battery to fuel pump relay con- nector terminals No.
  • Page 748 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) F: FUEL INJECTOR CIRCUIT CAUTION: • Check or repair only the faulty parts. • After repair or replacement of the faulty parts, conduct the Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.> and <Ref. to EN(H4SOw/ oOBD)(diag)-26, OPERATION, Inspection Mode.>...
  • Page 749 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO EACH FUEL Is the voltage more than 10 V? Go to step 3. Repair the har- INJECTOR. ness and connec- 1)Turn the ignition switch to OFF. tor. 2)Disconnect the connector from each cylinder NOTE: fuel injector.
  • Page 750 Diagnostics for Engine Starting Failure ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 1 Repair the ground Go to step 8. Ω? FUEL INJECTOR CONNECTOR. short circuit in har- Measure the resistance of harness between ness between ECM and fuel injector connector.
  • Page 751 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) 13.List of Diagnostic Trouble Code (DTC) A: LIST Item Contents of diagnosis Index Crankshaft position sen- • No signal entered from crankshaft <Ref. to EN(H4SOw/oOBD)(diag)-57, DTC 11 position sensor when starter switch is CRANKSHAFT POSITION SENSOR, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>...
  • Page 752 List of Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Item Contents of diagnosis Index Torque control signal (AT) • Abnormal signal is entered from <Ref. to EN(H4SOw/oOBD)(diag)-85, DTC 38 TCM. TORQUE CONTROL SIGNAL, Diagnostic Proce- • Harness connector between ECM dure with Diagnostic Trouble Code (DTC).> and TCM is in short or open.
  • Page 753 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) 14.Diagnostic Procedure with Diagnostic Trouble Code (DTC) A: DTC 11 CRANKSHAFT POSITION SENSOR • DIAGNOSIS: • No signal entered from crankshaft position sensor when ignition switch is ON. • The harness connector between ECM and crankshaft position sensor is open or shorted. •...
  • Page 754 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK CONDITION OF CRANKSHAFT PO- Are the crankshaft position Go to step 2. Tighten the crank- SITION SENSOR INSTALLATION. sensor installing bolts tight- shaft position sen- ened securely? sor installing bolts securely.
  • Page 755 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK ANY OTHER DTCs APPEARANCE. Is any other DTC displayed? Proceed with the A temporary poor diagnosis corre- contact. sponding to the DTC. EN(H4SOw/oOBD)(diag)-59...
  • Page 756 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) B: DTC 12 STARTER SWITCH • DIAGNOSIS: • The starter switch signal is abnormal. • The harness connector between ECM and starter switch is open or shorted. • TROUBLE SYMPTOM: • Failure of engine to start CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes.
  • Page 757 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND IG- Is the voltage more than 10 V? Repair the poor Repair the open or NITION SWITCH CONNECTOR. contact in ECM ground short cir- 1)Turn the ignition switch to OFF.
  • Page 758 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) C: DTC 13 CAMSHAFT POSITION SENSOR • DIAGNOSIS: • No signal entered from camshaft position sensor, but signal entered from crankshaft position sensor. • The harness connector between ECM and camshaft position sensor is open or shorted. •...
  • Page 759 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK CAMSHAFT POSITION SENSOR. Is the resistance 1 — 4 kΩ? Go to step 3. Replace the cam- 1)Remove the camshaft position sensor. shaft position sen- 2)Measure the resistance between connector sor.
  • Page 760 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) D: DTC 21 ENGINE COOLANT TEMPERATURE SENSOR • DIAGNOSIS: • The engine coolant temperature sensor signal is abnormal. • The harness connector between ECM and engine coolant temperature sensor is open or shorted. •...
  • Page 761 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ENGINE Is the voltage more than 10 V? Repair the battery Go to step 2. COOLANT TEMPERATURE SENSOR AND short circuit in har- ECM CONNECTOR. ness between 1)Turn the ignition switch to OFF.
  • Page 762 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ENGINE Is the resistance less than 5 Go to step 5. Repair the har- Ω? COOLANT TEMPERATURE SENSOR AND ness and connec- ECM CONNECTOR. tor. 1)Turn the ignition switch to OFF. NOTE: 2)Measure the resistance of harness between In this case, repair...
  • Page 763 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) E: DTC 22 KNOCK SENSOR • DIAGNOSIS: • The knock sensor signal is abnormal. • The harness connector between ECM and knock sensor is open or shorted. • TROUBLE SYMPTOM: • Poor driving performance CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes.
  • Page 764 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 3 V? Go to step 2. Go to step 3. 1)Turn the ignition switch to ON. 2)Measure the voltage between ECM connec- tor and chassis ground.
  • Page 765 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) F: DTC 24 IDLE AIR CONTROL SOLENOID VALVE • DIAGNOSIS: • The idle air control solenoid valve is not in function. • The harness connector between ECM and idle air control solenoid valve is open or shorted. •...
  • Page 766 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK POWER SUPPLY TO IDLE AIR CON- Is the voltage more than 10 V? Go to step 2. Repair the har- TROL SOLENOID VALVE. ness and connec- 1)Turn the ignition switch to OFF. tor.
  • Page 767 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK AIR BY-PASS LINE. Are foreign particles in the by- Remove the for- Replace the idle 1)Turn the ignition switch to OFF. pass air line? eign particles from air control solenoid 2)Remove the idle air control solenoid valve by-pass air line.
  • Page 768 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) G: DTC 26 INTAKE AIR TEMPERATURE SENSOR • DIAGNOSIS: • The intake air temperature sensor signal is abnormal. • The harness connector between ECM and intake air temperature sensor is open or shorted. •...
  • Page 769 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INTAKE AIR TEMPERATURE SEN- Is the resistance 2 — 3 kΩ at Go to step 2. Replace the intake SOR. 20°C (68°F)? air temperature 1)Turn the ignition switch to OFF. sensor.
  • Page 770 CHECK POOR CONTACT. Is there poor contact in ECM Repair the poor Contact with your Check poor contact in ECM connector. connector? contact in ECM SUBARU distribu- connector. tor service. NOTE: Inspection by your SUBARU distribu- tor service is re-...
  • Page 771 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) H: DTC 31 THROTTLE POSITION SENSOR • DIAGNOSIS: • The throttle position sensor signal is abnormal. • The throttle position sensor is installed abnormally. • The harness connector between ECM and throttle position sensor is open or shorted. •...
  • Page 772 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 1 Go to step 2. Repair the open Ω? THROTTLE POSITION SENSOR. circuit between 1)Disconnect the connector from ECM and ECM and throttle throttle position sensor.
  • Page 773 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) I: DTC 32 OXYGEN SENSOR • DIAGNOSIS: • The oxygen sensor is not in function. • The harness connector between ECM and oxygen sensor is open or shorted. • TROUBLE SYMPTOM: •...
  • Page 774 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK FOR OTHER CAUSES AFFECTING Is CO % more than 2% after Check the fuel Go to step 2. EXHAUST GAS. the engine warm up? system. NOTE: •Check for use of improper fuel. •Check if engine oil or coolant level is extremely low.
  • Page 775 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT VOLTAGE FOR ECM. Do 0.1 and 1 V waveform pat- Go to step 9. Replace the oxy- 1)Turn the ignition switch to OFF. terns alternately appear on the gen sensor.
  • Page 776 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) J: DTC 33 VEHICLE SPEED SIGNAL • DIAGNOSIS: • The vehicle speed signal is abnormal. • The harness connector between ECM and vehicle speed sensor is open or shorted. • TROUBLE SYMPTOM: •...
  • Page 777 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage more than 3 V? Go to step 3. Go to step 4. 1)Lift-up the vehicle. 2)Set the oscilloscope probe at ECM connec- tor terminal positive (+) and its ground lead at negative (−).
  • Page 778 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) K: DTC 35 PURGE CONTROL SOLENOID VALVE • DIAGNOSIS: • The purge control solenoid valve is not in function. • The harness connector between ECM and purge control solenoid valve is open or shorted. •...
  • Page 779 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK OPERATION SOUND OF PURGE Does the purge control sole- Go to step 2. Go to step 3. CONTROL SOLENOID VALVE. noid valve produce operating 1)Turn the ignition switch to OFF. sound? 2)Connect the test mode connector at lower portion of instrument panel (on driver’s side).
  • Page 780 CHECK POOR CONTACT. Is there poor contact in purge Repair the poor Contact with your Check poor contact in purge control solenoid control solenoid valve connec- contact in purge SUBARU distribu- valve connector. tor? control solenoid tor service. valve connector. NOTE:...
  • Page 781 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) L: DTC 38 TORQUE CONTROL SIGNAL • DIAGNOSIS: • Abnormal signal entered from TCM • The harness connector between ECM and TCM is shorted. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.>...
  • Page 782 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the resistance less than 10 Repair the ground Go to step 2. Ω? TCM CONNECTOR. short circuit in har- 1)Disconnect the connectors from ECM and ness between TCM.
  • Page 783 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) M: DTC 45 PRESSURE SENSOR • DIAGNOSIS: • The manifold absolute pressure sensor signal is abnormal. • The harness connector between ECM and manifold absolute pressure sensor is open or shorted. •...
  • Page 784 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK HARNESS BETWEEN ECM AND Is the voltage 4.5 — 5.5 V? Go to step 2. Repair the open or MANIFOLD ABSOLUTE PRESSURE SEN- ground short cir- SOR CONNECTOR. cuit in harness 1)Disconnect the connector from manifold between ECM and...
  • Page 785 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) N: DTC 46 CO RESISTOR (GENERAL SPEC. VEHICLES) • DIAGNOSIS: • The CO resistor signal is abnormal. • The harness connector between ECM and CO resistor is open or shorted. • The CO value is not adjusted to specifications. •...
  • Page 786 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage 0.5 — 4.5 V? Go to step 3. Go to step 2. 1)Turn the ignition switch to ON. 2)Measure the voltage between ECM and chassis ground.
  • Page 787 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) O: DTC 51 NEUTRAL POSITION SWITCH (MT MODEL) • DIAGNOSIS: • The neutral position switch signal is abnormal. • The harness connector between ECM and neutral position switch is open or shorted. •...
  • Page 788 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage 4.5 — 5.5 V in Go to step 3. Go to step 2. 1)Turn the ignition switch to ON. neutral position? 2)Measure the voltage between ECM and chassis ground.
  • Page 789 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) P: DTC 51 PARK/NEUTRAL POSITION SWITCH (AT MODEL) • DIAGNOSIS: • The park/neutral position switch signal is abnormal. • The shift cable is connected abnormally. • The harness connector between ECM/TCM and inhibitor switch is open or shorted. •...
  • Page 790 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK INPUT SIGNAL FOR ECM. Is the voltage less than 1 V? Go to step 2. Go to step 3. 1)Turn the ignition switch to ON. 2)Measure the voltage between ECM and chassis ground in selector lever “N”...
  • Page 791 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Q: DTC 85 CHARGE SYSTEM • DIAGNOSIS: • Power source voltage of the ECM is low or high. • TROUBLE SYMPTOM: • Charge warning light comes on. CAUTION: After repair or replacement of faulty parts, conduct Clear Memory and inspection modes. <Ref. to EN(H4SOw/oOBD)(diag)-28, OPERATION, Clear Memory Mode.>...
  • Page 792 Diagnostic Procedure with Diagnostic Trouble Code (DTC) ENGINE (DIAGNOSTICS) Step Check CHECK GENERATOR. Is the voltage 10.8 V — 16.2 Go to step 2. Repair the genera- 1)Start the engine. tor. <Ref. to 2)Idle after warm-up. SC(H4SO)-13, 3)Measure the voltage between generator B Generator.>...
  • Page 793 General Diagnostic Table ENGINE (DIAGNOSTICS) 15.General Diagnostic Table A: INSPECTION NOTE: • Malfunction of parts other than those listed is also possible. • The right-hand priority column indicates inspection priority of probable causes of the symptom. Carry out the check starting from A. Symptom Problem parts Priority...
  • Page 794 General Diagnostic Table ENGINE (DIAGNOSTICS) Symptom Problem parts Priority 5. Rough idling 1) Spark plug 2) Manifold absolute pressure sensor 3) Engine coolant temperature sensor 4) Pressure regulator 5) Idle air control solenoid valve 6) Air leak in air intake system 7) ECM power supply 8) Throttle position sensor 9) Camshaft position sensor...
  • Page 795 General Diagnostic Table ENGINE (DIAGNOSTICS) Symptom Problem parts Priority 13. Poor engine revving 1) Pressure regulator 2) Manifold absolute pressure sensor 3) Engine coolant temperature sensor 4) Throttle sensor 5) Fuel pump 14. Remarks 1) ECM power supply 2) Manifold absolute pressure sensor 3) Pressure regulator 4) Idle air control solenoid valve 5) Air leak in air intake system...
  • Page 796 General Diagnostic Table ENGINE (DIAGNOSTICS) EN(H4SOw/oOBD)(diag)-100...

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