Subaru 2009 IMPREZA Service Manual page 1382

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
electronic throttle control.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B134) No. 19 — Chassis ground:
(B134) No. 28 — Chassis ground:
2 CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Connect the connector to ECM.
2) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 4 — Engine ground:
Check
Is the resistance 1 M or
more?
Is the resistance 1 M or
more?
EN(H4DOTC)(diag)-161
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Repair the short
circuit to ground in
harness between
ECM and elec-
tronic throttle con-
trol connector.
Replace the elec- Repair the short
tronic throttle con- circuit to ground in
trol. <Ref. to harness between
FU(H4DOTC)-14, ECM and elec-
Throttle Body.> tronic throttle con-
trol connector.
Replace the ECM if
defective. <Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>