Subaru 2002 IMPREZA Service Manual page 378

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
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 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 pressure regulator and pres-
sure regulator vacuum hose.
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
~ B D - I I general scan tool.
NOTE:
*Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE. <Ref.
to EN(D0HC TURBO)-38, Subaru Select Mon
itor.>
*OBD-ll general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
CHECK 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 OF!?
4)Turn all accessory switches to OFF.
5)Read the data of pressure sensor signal
using Subaru Select Monitor or OBD-ll genera
scan tool.
NOTE:
*Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE. <Ref
to EN(D0HC TURBO)-38, Subaru Select Mon
itor.>
*OBD-ll general scan tool
For detailed operation procedure, refer to the
OBD-ll General Scan Tool Instruction Manual.
Specification:
Ignition
ON
. *Intake manifold absolute pressure
73.3
-
106.6 kPa (550
-
800 mmHg,
21.65
-
31.50 inHg)
24.0
-
41.3 kPa (180
-
310 mmHg,
7.09
-
12.20 inHg)
Idling
Check
;
fuel pressure between 206
nd 235 kPa (2.1
-
2.4 kg/
n2, 30
-
34 psi)?
j
temperature greater than
0°C (1 40"F)?
j
the value within the specifi-
ations?
Yes
io
to step 5.
io to
step 6.
i o to step 7.
No
3epair the follow-
ng items.
:uel pressure toa
iigh
Faulty pressure
egulator
Clogged fuel
'eturn line or bent
lose
'uel pressure toc
ow
1
Faulty pressure
'egulator
1
Improper fuel
lump discharge
1
Clogged fuel
supply line
3eplace the
mgine coolant
emperature sen-
sor. <Ref. to
'U( DOHC
rURBO)-29,
Engine Coolant
remperature Sen-
;or.>
Replace the mass
3ir flow and pres-
sure sensor. <Ref
to
FU(D0HC
TURBO)-34, Mas!
Air Flow and
Intake Air Temper
ature Sensor.>
EN(D0HC TURBO)-154