Subaru Legacy 2003 Service Manual page 2398

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK FWD SWITCH.
When fuse is inserted to FWD switch, does
LED light up?
2 CHECK FWD INDICATOR LIGHT.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove FWD indicator light bulb from
combination meter.
Is FWD indicator light bulb OK?
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM and FWD
switch.
3) Measure resistance of harness between
TCM and FWD switch connector.
Connector & terminal
(B55) No. 20 — (F67) No. 36:
Is the measured value less than the speci-
fied value?
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
Measure resistance of harness connector
between TCM and body to make sure that cir-
cuit does not short.
Connector & terminal
(B55) No. 20 — Chassis ground:
Does the measured value exceed the specified
value?
5 CHECK HARNESS CONNECTOR BETWEEN
FWD SWITCH AND CHASSIS GROUND.
Measure resistance of harness between FWD
switch and chassis ground.
Connector & terminal
(F67) No. 35 — Chassis ground:
Is the measured value less than the specified
value?
6 CHECK INPUT SIGNAL FOR TCM.
1) Turn ignition switch to OFF.
2) Connect connector to TCM and FWD
switch.
3) Turn ignition switch to ON.
4) Measure signal voltage for TCM while
installing the fuse to FWD switch connec-
tor.
Connector & terminal
(B55) No. 20 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value?
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Value
LED lights up.
Bulb is normal.
1 Ω
1 MΩ
1 Ω
1 V
AT-123
Yes
Go to step CHECK Go to step 2.
BRAKE
SWITCH.<Ref. to
AT-125, CHECK
BRAKE SWITCH.,
Diagnostic Proce-
dure for No-diag-
nostic Trouble
Code (DTC).>
Go to step 3. Replace FWD indi-
cator light bulb.
<Ref. to IDI-14,
Combination
Meter Assembly.>
Go to step 4. Repair open circuit
in harness
between TCM and
FWD switch con-
nector.
Go to step 5. Repair short circuit
in harness
between TCM and
FWD switch con-
nector.
Go to step 6. Repair open circuit
in harness
between FWD
switch connector
and chassis
ground.
Go to step 7. Go to step 11.
No