Subaru Legacy 2003 Service Manual page 2399

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
7 CHECK INPUT SIGNAL FOR TCM.
Measure signal voltage for TCM while remov-
ing the fuse from FWD switch connector.
Connector & terminal
(B55) No. 20 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the specified
value?
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM and com-
bination meter.
3) Measure resistance of harness between
TCM and diagnosis connector.
Connector & terminal
(B56) No. 2 — (i10) No. 16:
Is the measured value less than the speci-
fied value?
9 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
Measure resistance of harness connector
between TCM and chassis ground to make
sure that circuit does not short.
Connector & terminal
(B56) No. 2 — Chassis ground:
Does the measured value exceed the specified
value?
10 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Turn ignition switch to OFF.
2) Connect connector to TCM and combina-
tion meter.
3) Turn ignition switch to ON.
4) Measure signal voltage for TCM while
installing and removing the fuse to FWD
switch connector.
Connector & terminal
(B56) No. 2 — Chassis ground:
Is the measured value less than the speci-
fied value?
11 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
Measure signal voltage for TCM while remov-
ing the fuse from FWD switch connector.
Connector & terminal
(B56) No. 2 — Chassis ground:
Does the measured value exceed the specified
value?
12 CHECK POOR CONTACT.
Is there poor contact in FWD switch circuit?
Step Value
9 V
1 Ω
1 MΩ
1 V
9 V
There is poor contact.
AT-124
Yes
Go to step 8. Replace TCM.
<Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>
Go to step 9. Repair open circuit
in harness
between TCM and
combination meter
and poor contact
in coupling con-
nector.
Go to step 10. Repair short circuit
in harness
between TCM and
combination meter
connector.
Go to step 11. Go to step 12.
Go to step 12. Replace TCM.
<Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>
Repair poor con- Replace TCM.
tact. <Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>
No