Subaru IMPREZA 2004 Service Manual page 70

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
6 CHECK POWER SUPPLY LINE.
1)Turn the ignition switch to ON.
2)Measure the voltage between fuel injector
and engine ground on faulty cylinders.
Connector & terminal
#1 (E5) No. 2 (+) — Engine ground ( − − − − ):
#2 (E16) No. 2 (+) — Engine ground ( − − − − ):
#3 (E6) No. 2 (+) — Engine ground ( − − − − ):
#4 (E17) No. 2 (+) — Engine ground ( − − − − ):
7 CHECK HARNESS BETWEEN FUEL INJEC-
TOR AND ECM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from fuel injector
on faulty cylinder.
3)Turn the ignition switch to ON.
4)Measure the voltage between ECM connec-
tor and chassis ground on faulty cylinders.
Connector & terminal
#1 (B134) No. 34 (+) — Chassis
ground ( − − − − ):
#2 (B134) No. 23 (+) — Chassis
ground ( − − − − ):
#3 (B134) No. 22 (+) — Chassis
ground ( − − − − ):
#4 (B134) No. 8 (+) — Chassis
ground ( − − − − ):
8 CHECK FUEL INJECTOR.
1)Turn the ignition switch to OFF.
2)Measure the resistance between fuel injector
terminals on faulty cylinder.
Terminals
No. 1 — No. 2:
9 CHECK INSTALLATION OF CAMSHAFT PO-
SITION SENSOR/CRANKSHAFT POSITION
SENSOR.
10 CHECK CRANKSHAFT SPROCKET.
Remove the timing belt cover.
11 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft using ST, and align align-
ment mark on crankshaft sprocket with align-
ment mark on cylinder block.
ST 499987500 CRANKSHAFT SOCKET
EN(H4SO)(diag)-147
Check
Is the voltage more than 10 V? Repair poor con-
Is the voltage more than 10 V? Repair battery
Is the resistance less than 1
Ω?
Is the camshaft position sensor
or crankshaft position sensor
loosely installed?
Is the crankshaft sprocket
rusted or does it have broken
teeth?
Is the timing belt dislocated
from its proper position?
ENGINE (DIAGNOSTICS)
Yes
Repair harness
tact in all connec- and connector.
tors in fuel injector
NOTE:
circuit.
In this case, repair
the following:
• Open circuit in
harness between
main relay and fuel
injector connector
on faulty cylinders
• Poor contact in
coupling connector
• Poor contact in
main relay connec-
tor
• Poor contact in
fuel injector con-
nector on faulty
cylinders
Go to step 8.
short circuit in har-
ness between
ECM and fuel
injector. After
repair, replace the
ECM. <Ref. to
FU(H4SO)-47,
Engine Control
Module (ECM).>
Replace the faulty Go to step 9.
fuel injector <Ref.
to FU(H4SO)-38,
Fuel Injector.> and
ECM <Ref. to
FU(H4SO)-47,
Engine Control
Module (ECM).>
Tighten camshaft Go to step 10.
position sensor or
crankshaft posi-
tion sensor.
Replace the crank- Go to step 11.
shaft sprocket.
<Ref. to
ME(H4SO)-55,
Crankshaft
Sprocket.>
Repair installation Go to step 12.
condition of timing
belt. <Ref. to
ME(H4SO)-48,
Timing Belt
Assembly.>
No