Subaru Forester 2004 Service Manual page 241

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK ACCELERATOR PEDAL POSITION
SENSOR OUTPUT.
1) Turn the ignition switch to ON.
2) Read the data of main accelerator pedal
position sensor signal using Subaru Select
Monitor.
3) Check the voltage change by shaking the
harness and connector of ECM, engine har-
ness connector and accelerator pedal position
sensor connector harness.
2 CHECK POOR CONTACT.
Check poor contact in connector between
ECM and accelerator pedal position sensor.
3 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from the acceler-
ator pedal position sensor.
4) Measure the resistance between ECM con-
nector and accelerator pedal position sensor con-
nector.
Connector & terminal
(B136) No. 34 — (B315) No. 4:
4 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Connect the ECM connector.
2) Measure the resistance between accelerator
pedal position sensor connector and engine
ground.
Connector & terminal
(B315) No. 4 — Engine ground:
5 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between accelerator
pedal position sensor connector and engine
ground.
Connector & terminal
(B315) No. 3 (+) — Engine ground (
4) Check the voltage is above the specified
value when shaking the harness and connec-
tor of ECM while monitoring the value with volt-
age meter.
6 CHECK POWER SUPPLY OF ACCELERA-
TOR PEDAL POSITION SENSOR.
1) Measure the voltage between accelerator
pedal position sensor connector and engine
ground.
Connector & terminal
(B315) No. 5 (+) — Engine ground (
2) Check the voltage is below the specified
value when shaking the harness and connec-
tor of ECM while monitoring the value with volt-
age meter.
Check
Is the voltage less than 4.8 V? Go to step 2.
Is there poor contact?
Is the resistance less than 1
Ω?
Is the resistance less than 5
Ω?
Is the voltage more than 6 V?
−
):
Is the voltage less than 4.8 V? Go to step 7.
−
):
EN(H4DOTC 2.5)-240
Yes
Go to step 3.
Repair the poor Temporary poor
contact. contact occurred,
but it is normal at
present.
Go to step 4. Repair the open
circuit of harness
connector.
Go to step 5. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective.
Go to step 6. Repair battery
short circuit in har-
ness between
ECM connector
and accelerator
pedal position sen-
sor connector.
Repair short circuit
in harness between
ECM connector and
accelerator pedal
position sensor con-
nector.
No