Subaru 2002 IMPREZA Service Manual page 589

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
4 CHECK FUEL PRESSURE.
After connecting the pressure regulator vac-
uum hose, measure the fuel pressure.
Warning:
Before removing the fuel pressure gauge,
release fuel pressure.
NOTE:
•If the fuel pressure does not increase,
squeeze the 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-34, Subaru Select Monitor.>
•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 SIGNAL.
1)Start the engine and warm-up engine until
coolant temperature is greater than 60°C
(140°F).
2)Place the selector lever in "N" or "P" 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-34, Subaru Select Monitor.>
•OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
Specification:
Idling
24.0 — 41.3 kPa (180 — 310 mmHg, 7.09
— 12.20 inHg)
Ignition ON
73.3 — 106.6 kPa (550 — 800 mmHg,
21.65 — 31.50 inHg)
Check
Is the fuel pressure between
206 — 235 kPa (2.1 — 2.4
2
kg/cm , 30 — 34 psi)?
Is the temperature between
70°C (158°F) and 100°C
(212°F)?
Is the voltage within the speci-
fications?
EN-157
ENGINE (DIAGNOSTICS)
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-
31, Engine Cool-
ant Temperature
Sensor.>
Contact with your Replace the intake
Subaru distributor air temperature
service. and pressure sen-
sor. <Ref. to FU-
NOTE:
37, Intake Air
Inspection by DTM
Temperature and
is required, be-
Pressure Sensor.>
cause probable
cause is deteriora-
tion of multiple
parts.
No