Subaru 2009 IMPREZA Service Manual page 715

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
accelerator pedal position sensor.
3) Measure the resistance of harness between
ECM and accelerator pedal position sensor
connector.
Connector & terminal
(B135) No. 31 — (B315) No. 3:
(B135) No. 30 — (B315) No. 2:
2 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Connect the connector to ECM.
2) Measure the resistance between accelera-
tor pedal position sensor connector and chassis
ground.
Connector & terminal
(B315) No. 2 — Chassis ground:
3 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between accelerator
pedal position sensor connector and chassis
ground.
Connector & terminal
(B315) No. 3 (+) — Chassis ground (–):
4 CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM con-
nectors.
Connector & terminal
(B135) No. 22 — (B135) No. 31:
Check
Is the resistance less than 1 ? Go to step 2.
Is the resistance less than 1 ? Go to step 3.
Is the voltage 4.85 V or more? Repair the short
Is the resistance 1 M or
more?
EN(H4SO)(diag)-298
Yes No
Repair the harness
and connector.
• Open circuit in
harness between
ECM and accelera-
tor pedal position
sensor connector
• Poor contact of
joint connector
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and engine
ground
• Poor contact of
ECM connector
• Poor contact of
coupling connector
Go to step 4.
circuit to power
supply in the har-
ness between the
ECM and accelera-
tor pedal position
sensor connector.
Repair the poor Repair the short
contact of acceler- circuit to power
ator pedal position supply in the har-
sensor connector. ness between the
Replace the accel- ECM and accelera-
erator pedal if tor pedal position
defective. <Ref. to sensor connector.
SP(H4SO)-4,
Accelerator
Pedal.>