Subaru Legacy 2003 Service Manual page 694

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Start engine, and warm-up the engine.
2) Turn ignition switch to OFF.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from ECM and
TCM.
3) Measure resistance of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 15 — Chassis ground:
Does the measured value exceed the spec-
ified value?
3 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure resistance of harness between ECM
and TCM connector.
Connector & terminal
(B136) No. 15 — (B55) No. 10:
Is the measured value less than the specified
value?
Value
3 V
1 MΩ
1 Ω
EN(H4SO)-297
ENGINE (DIAGNOSTICS)
Yes
Repair poor con- Go to step 2.
tact in ECM con-
nector.
Go to step 3. Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
Repair poor con- Repair open circuit
tact in ECM or in harness
TCM connector. between ECM and
TCM connector.
No