Subaru IMPREZA 2004 Service Manual page 564

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1)Start the engine, and warm-up the engine.
2)Turn the ignition switch to OFF.
3)Disconnect the connector from TCM.
4)Turn the ignition switch to ON.
5)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground ( − − − − ):
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground ( − − − − ):
Check
Is the voltage less than 3 V?
Is the voltage more than 10 V
by shaking the harness and
connector of ECM?
EN(H4SO)(diag)-255
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair battery
short circuit in har-
ness between
ECM and TCM
connector. After
repair, replace the
ECM. <Ref. to
FU(H4SO)-47,
Engine Control
Module (ECM).>
Repair battery Contact with SUB-
short circuit in har- ARU distributor
ness between service.
ECM and TCM
NOTE:
connector. After
Inspection by DTM
repair, replace the
is required,
ECM. <Ref. to
cause
FU(H4SO)-47,
cause is deteriora-
Engine Control
tion of
Module (ECM).>
parts.
No
be-
probable
multiple