Subaru Legacy 2003 Service Manual page 700

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 18 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and chassis
ground.
Connector & terminal
(B136) No. 18 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the specified
value?
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
4 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 TCM connector.
Connector & terminal
(B136) No. 18 — (B56) No. 14:
5 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure resistance of harness between ECM
and chassis ground.
Connector & terminal
(B136) No. 18 — Chassis ground:
Is the measured value less than the specified
value?
6 CHECK POOR CONTACT.
Check poor contact in TCM connector.
Is there poor contact in TCM connector?
Value
4.5 V
10 V
There is poor contact.
1 Ω
10 Ω
There is poor contact.
EN(H4SO)-303
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 4.
Repair battery Go to step 3.
short circuit in har-
ness between
ECM and TCM
connector.
Repair poor con- Contact SUBARU
tact in ECM con- distributor service.
nector.
NOTE:
Inspection by DTM
is required,
cause
cause is deteriora-
tion of
parts.
Go to step 5. Repair open circuit
in harness
between ECM and
TCM connector.
Go to step 6. Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
Repair poor con- Replace TCM.
tact in TCM con- <Ref. to AT-76,
nector. Transmission Con-
trol Module
(TCM).>
No
be-
probable
multiple