Subaru 2003 LEGACY Service Manual page 71

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure resistance of harness between TCM
connector and chassis ground.
Connector & terminal
(B56) No. 14 — Chassis ground:
(B56) No. 5 — Chassis ground:
Does the measured value exceed the specified
value?
3 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect connectors to TCM and ECM.
2) Turn ignition switch to ON (engine OFF).
3) Measure voltage between TCM connector
terminals.
Connector & terminal
(B56) No. 14 (+) — Chassis ground ( − − − − ):
(B56) No. 5 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
4 CHECK POOR CONTACT.
Is there poor contact in torque control signal
circuit?
5 CHECK GROUND LINE BETWEEN TRANS-
MISSION AND BODY.
Check installing condition of ground line in
transmission and body.
Is there any dirt or rust at ground line installing
point?
6 CHECK GROUND LINE BETWEEN TRANS-
MISSION AND BODY.
Check installing condition of ground line in
transmission and body.
Is tightening torque value within specification?
7 CHECK GROUND LINE INSIDE TRANSMIS-
SION.
1) Drain AT fluid and remove oil pan.
2) Check tightening torque value of ground
line installing bolt.
Is tightening torque value within specifica-
tion?
8 CHECK GROUND CIRCUIT OF ECM.
<Ref. to AT-52, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
Is there any trouble?
9 RECHECK OUTPUT SIGNAL EMITTED
FROM TCM.
Measure voltage between TCM connector and
chassis ground.
Connector & terminal
(B56) No. 14 (+) — Chassis ground ( − − − − ):
(B56) No. 5 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the specified
value?
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Value
1 MΩ
4.8 V
There is poor contact.
10 — 16 N·m (1.0 — 1.6 kgf-m,
7.2 — 11.6 ft-lb)
7 — 9 N·m (0.7 — 0.9 kgf-m,
5.1 — 6.5 ft-lb)
Ground terminals and ground
circuit has a problem.
4.8 V
AT-69
Yes
Go to step 3. Repair short circuit
in harness
between TCM and
ECM connector.
Even if "POWER" Go to step 4.
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
harness or con-
nector in the TCM
and ECM.
Repair poor con- Go to step 5.
tact.
Remove dirt and Go to step 6.
rust.
Go to step 7. Tighten to speci-
fied torque.
Go to step 9. Tighten to speci-
fied torque.
Repair ground ter- Go to step 9.
minal and/or
ground circuit of
ECM.
Replace TCM. Replace ECM.
<Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>
No