Subaru Impreza 2004 - Page 564

EN(H4SO)(diag)-255
ENGINE (DIAGNOSTICS)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
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 (
−
−−
−
):
Is the voltage less than 3 V? 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).>
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 (
−
−−
−
):
Is the voltage more than 10 V
by shaking the harness and
connector of ECM?
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).>
Contact with SUB-
ARU distributor
service.
N
O
TE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.