Subaru 2009 IMPREZA Service Manual page 709

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 between ECM and
chassis ground.
Connector & terminal
(B135) No. 21 — Chassis ground:
(B135) No. 23 — Chassis ground:
(B135) No. 23 — (B136) No. 6:
2 CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Connect the connector to ECM.
2) Measure the resistance between accelera-
tor pedal position sensor connector and chassis
ground.
Connector & terminal
(B315) No. 6 — Chassis ground:
Check
Is the resistance 1 M or
more?
Is the resistance 1 M or
more?
EN(H4SO)(diag)-292
Yes No
Go to step 2. Repair the short
circuit to ground in
harness between
ECM and accelera-
tor pedal position
sensor connector.
Replace the accel- Repair the short
erator pedal. <Ref. circuit to ground in
to SP(H4SO)-4, harness between
Accelerator ECM and accelera-
Pedal.> tor pedal position
sensor connector.
Replace the ECM if
defective. <Ref. to
FU(H4SO)-45,
Engine Control
Module (ECM).>