Subaru Legacy 2003 Service Manual page 2388

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK TROUBLE CODE.
Do multiple trouble codes appear in the on-
board diagnostics test mode?
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND VDCCM.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM and
VDCCM.
3) Measure resistance of harness between
TCM and VDCCM connector.
Connector & terminal
(B56) No. 18 — (F87) No. 81:
Is the measured value less than the speci-
fied value?
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND VDCCM.
Measure resistance of harness between TCM
and VDCCM connector.
Connector & terminal
(B56) No. 9 — (F87) No. 83:
Is the measured value less than the specified
value?
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND VDCCM.
Measure resistance of harness between TCM
and VDCCM connector.
Connector & terminal
(B56) No. 18 — Chassis ground:
Is the measured value less than the specified
value?
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND VDCCM.
Measure resistance of harness between TCM
and VDCCM connector.
Connector & terminal
(B56) No. 9 — Chassis ground:
Is the measured value less than the specified
value?
6 PREPARE OSCILLOSCOPE.
Do you have oscilloscope?
7 CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and VDCCM.
2) Turn ignition switch to ON (engine OFF).
3) Measure voltage between TCM connector
and chassis ground.
Connector & terminal
(B56) No. 9 (+) — Chassis ground ( − − − − ):
(B56) No. 18 (+) — Chassis ground ( − − − − ):
Does input voltage value change?
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Value
DTC is displayed.
1 Ω
1 Ω
1 MΩ
1 MΩ
Oscilloscope is available.
Input voltage varies.
AT-113
Yes
Go to another trou- Go to step 2.
ble code.
Go to step 3. Repair open circuit
in harness
between TCM and
VDCCM, and poor
contact in cou-
pling connector.
Go to step 4. Repair open circuit
in harness
between TCM and
VDCCM, and poor
contact in cou-
pling connector.
Go to step 5. Repair short circuit
in harness
between TCM and
VDCCM connec-
tor.
Go to step 6. Repair short circuit
in harness
between TCM and
VDCCM connec-
tor.
Go to step 8. Go to step 7.
Go to step 10. Repair poor con-
tact in VDCCM.
No