Subaru Legacy 2005 Service Manual page 1435

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
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.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-24, Subaru Select Mon-
itor.>
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 connectors from accelerator
pedal position sensor.
4) Measure the resistance between ECM con-
nector and accelerator pedal position sensor
connector.
Connector & terminal
(B136) No. 17 — (B315) No. 5:
(B136) No. 15 — (B315) No. 3:
4 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
Measure the resistance between ECM connec-
tor and chassis ground.
Connector & terminal
(B136) No. 17 — Chassis ground:
(B136) No. 15 — Chassis ground:
5 CHECK POWER SUPPLY OF ACCELERA-
TOR 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 chassis
ground.
Connector & terminal
(B315) No. 3 (+) — Chassis ground (
6 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
Measure the resistance of accelerator pedal
position sensor.
Terminals
No. 3 — No. 4:
7 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
Measure the resistance of accelerator pedal
position sensor.
Terminals
No. 5 — No. 4:
Check the measured value is within the specifi-
cation without depressing the accelerator
pedal.
Check
Is the voltage more than 0.4 V? Go to step 2.
Is there poor contact?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the voltage 4.5 — 5.5 V?
−
):
Is the resistance 1.2 — 4.8
kΩ?
Is the resistance 0.2 — 1.0
kΩ?
EN(H4DOTC)(diag)-195
ENGINE (DIAGNOSTICS)
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 chas-
sis short circuit of
harness.
Go to step 6. Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4DOTC)-
34, Engine Con-
trol Module
(ECM).>
Go to step 7. Replace the accel-
erator pedal posi-
tion sensor.
Go to step 8. Replace the accel-
erator pedal posi-
tion sensor.
No