Subaru Legacy 2002 Service Manual page 672

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
4 CHECK FUEL PRESSURE.
After connecting pressure regulator vacuum
hose, measure fuel pressure.
WARNING:
Before removing fuel pressure gauge,
release fuel pressure.
NOTE:
¼ If fuel pressure does not increase, squeeze
fuel return hose 2 to 3 times, then measure
fuel pressure again.
¼ If out of specification as measured at this
step, check or replace pressure regulator and
pressure regulator vacuum hose.
5 CHECK ENGINE COOLANT TEMPERA-
TURE SENSOR.
1) Start the engine and warm-up completely.
2) Read data of engine coolant temperature
sensor signal using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
¼ 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" posi-
tion.
3) Turn A/C switch to OFF.
4) Turn all accessory switches to OFF.
5) Read data of intake manifold pressure sen-
sor signal using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
¼ 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)
Step
Is fuel pressure between
206 and 235 kPa (2.1 —
2.4 kg/cm
Is temperature between
70°C (158°F) and 100°C
(212°F)?
Is the voltage within the
specifications?
EN-155
Check Yes
Go to step 5.
2
, 30 — 34 psi)?
Go to step 6.
Contact with your
Subaru distributor
service.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.
Engine (Diagnostics)
No
Repair the follow-
ing items.
Fuel pressure
too high
¼ Faulty pressure
regulator
¼ Clogged fuel
return line or bent
hose
Fuel pressure
too low
¼ Faulty pressure
regulator
¼ Improper fuel
pump discharge
¼ Clogged fuel
supply line
Replace engine
coolant tempera-
ture sensor. <Ref.
to FU-29, Engine
Coolant Tempera-
ture Sensor.>
Replace intake air
temperature and
pressure sensor.
<Ref. to FU-37,
Intake Air Tem-
perature and
Pressure Sensor.>