Subaru 2002 IMPREZA Service Manual page 1320

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
4 CHECK FUEL PRESSURE.
After connecting the pressure regulator vac-
uum hose, measure fuel pressure.
Warning:
Before removing the fuel pressure gauge,
release fuel pressure.
NOTE:
•If the fuel pressure does not increase,
squeeze fuel return hose 2 to 3 times, then
measure fuel pressure again.
•If out of specification as measured at this
step, check or replace the pressure regulator
and pressure regulator vacuum hose.
5 CHECK ENGINE COOLANT TEMPERATURE
SENSOR.
1)Start the engine and warm-up completely.
2)Read the data of engine coolant temperature
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".
<Ref. to EN(TURBO)-34, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
6 CHECK INTAKE MANIFOLD PRESSURE
SENSOR.
1)Start the engine and warm-up engine until
coolant temperature is greater than 60°C
(140°F).
2)Place the shift lever in neutral position.
3)Turn the A/C switch to OFF.
4)Turn all accessory switches to OFF.
5)Read the data of intake manifold pressure
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".
<Ref. to EN(TURBO)-34, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Specification:
•Intake manifold absolute pressure
Ignition ON
73.3 — 106.6 kPa (550 — 800 mmHg,
21.65 — 31.50 inHg)
Idling
24.0 — 41.3 kPa (180 — 310 mmHg, 7.09
— 12.20 inHg)
Check
Is the fuel pressure between
206 — 235 kPa (2.1 — 2.4
2
kg/cm , 30 — 34 psi)?
Is the temperature greater than
60°C (140°F)?
Is the value within the specifi-
cations?
EN(TURBO)-160
Yes
Go to step 5. Repair the follow-
ing items.
Fuel pressure too
high:
• Faulty pres-
sure regulator
• Clogged fuel
return line or
bent hose
Fuel pressure too
low:
• Faulty pres-
sure regulator
• Improper fuel
pump discharge
• Clogged fuel
supply line
Go to step 6. Replace the
engine coolant
temperature sen-
sor. <Ref. to
FU(TURBO)-29,
Engine Coolant
Temperature Sen-
sor.>
Go to step 7. Replace the mass
air flow and intake
manifold pressure
sensor. <Ref. to
FU(TURBO)-34,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
No