Subaru Legacy 2002 Service Manual page 1500

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM and TCM.
3) Measure resistance of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 20 — Chassis ground:
3 CHECK OUTPUT SIGNAL FOR ECM.
1) Connect connector to ECM.
2) Turn ignition switch to ON.
3) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 20 (+) — Chassis ground
(−):
4 CHECK TROUBLE CODE FOR AUTOMATIC
TRANSMISSION.
Read trouble code for automatic transmission.
<Ref. to AT-21, Read Diagnostic Trouble
Code (DTC).>
Step
Is the voltage less than 1
V?
Is the resistance less than
10 Ω?
Is the voltage more than 5
V?
Does trouble code appear
for automatic transmission?
EN(H6)-293
Check Yes
Go to step 2.
Repair ground
short circuit in
harness between
ECM and TCM
connector.
Go to step 4.
Inspect trouble
code for auto-
matic transmis-
sion. <Ref. to
AT-40, Diagnostic
Procedure with
Diagnostic
Trouble Code
(DTC).>
Engine (DIAGNOSTICS)
No
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact in
ECM connector
¼ Poor contact in
TCM connector
Go to step 3.
Repair poor con-
tact in ECM con-
nector.
Replace TCM.
<Ref. to AT-49,
Transmission
Control Module
(TCM).>