Subaru Legacy 2002 Service Manual page 1886

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK POWER SWITCH OPERATION.
2 CHECK POWER SWITCH OPERATION.
3 CHECK POWER INDICATOR LIGHT.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove POWER indicator light bulb from
combination meter.
4 CHECK POWER SWITCH GROUND LINE.
1) Turn ignition switch to OFF.
2) Disconnect connector from power switch.
3) Measure resistance of harness connector
between power switch and chassis ground.
Connector & terminal
(B116) No. 4 — Chassis ground:
5 CHECK POWER SWITCH.
1) Power switch turned ON.
2) Measure resistance between terminals of
power switch.
Terminals
No. 3 — No. 4:
6 CHECK POWER SWITCH.
1) Power switch turned OFF.
2) Measure resistance between terminals of
power switch.
Terminals
No. 3 — No. 4:
7 CHECK HARNESS CONNECTOR
BETWEEN TCM AND POWER SWITCH.
Measure resistance of harness connector
between TCM and power switch.
Connector & terminal
(B55) No. 23 — (B116) No. 3:
8 CHECK HARNESS CONNECTOR
BETWEEN TCM AND POWER SWITCH.
Measure resistance of harness connector
between TCM and chassis ground.
Connector & terminal
(B55) No. 23 — Chassis ground:
9 CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and power
switch.
2) Turn ignition switch ON (with engine OFF).
3) Measure signal voltage for TCM while turn-
ing power switch OFF.
Connector & terminal
(B55) No. 23 (+) — Chassis ground (–):
Step
When power switch is
turned OFF, does LED light
up?
When power switch is
turned ON, does LED light
up?
Is POWER indicator light
bulb OK?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is the resistance more than
1 MΩ?
Is the resistance less than
1 Ω?
Is the resistance more than
1 MΩ?
Is the voltage more than 10
V?
AT-117
Automatic Transmission (Diagnostics)
Check Yes
Go to step 5.
Go to step
CHECK INHIBI-
TOR SWITCH.
<Ref. to AT-120,
CHECK INHIBI-
TOR SWITCH.,
Diagnostic Proce-
dure for No-diag-
nostic Trouble
Code (DTC).>
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Go to step 8.
Go to step 9.
Go to step 10.
No
Go to step 2.
Go to step 3.
Replace POWER
indicator light
bulb. <Ref. to IDI-
15, Combination
Meter Assembly.>
Repair open cir-
cuit in harness
between power
switch and chas-
sis ground.
Repair power
switch.
Repair power
switch.
Repair open cir-
cuit in harness
between TCM and
power switch con-
nector.
Repair short cir-
cuit in harness
between TCM and
power switch con-
nector.
Replace TCM.
<Ref. to AT-49,
Transmission
Control Module
(TCM).>