Subaru 2002 IMPREZA Service Manual page 677

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODE (DTC) ON DISPLAY.
2 CHECK AIR INTAKE SYSTEM.
3 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 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 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
20.0 — 46.7 kPa (150 — 350 mmHg, 5.91
— 13.78 inHg)
4 CHECK THROTTLE POSITION.
Read the data of throttle position 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 procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Check
Is any other DTC displayed?
Are there holes, loose bolts or
disconnection of hose on the
air intake system?
Is the value within the specifi-
cations?
Is the throttle positioning ratio
equal to or less than 5 % when
throttle is fully closed?
EN-245
ENGINE (DIAGNOSTICS)
Yes
Inspect the rele- Go to step 2.
vant DTC using
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN-83, List of
Diagnostic Trou-
ble Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect P1146.
Repair the air Go to step 3.
intake system.
Go to step 4. Replace the intake
air temperature
sensor and pres-
sure sensor. <Ref.
to FU-37, Intake
Air Temperature
and Pressure Sen-
sor.>
Go to step 5. Adjust or replace
the throttle posi-
tion sensor. <Ref.
to FU-35, Throttle
Position Sensor.>
No