Subaru Legacy 2002 Service Manual page 740

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
2 CHECK HARNESS BETWEEN TCM AND
BRAKE LIGHT SWITCH CONNECTOR.
1) Disconnect connectors from TCM and
brake light switch.
2) Measure resistance of harness between
TCM and brake light switch connector.
Connector & terminal
(B55) No. 12 — (B64) No. 2:
(B55) No. 12 — (B65) No. 3 (With
cruise control):
3 CHECK HARNESS BETWEEN TCM AND
BRAKE LIGHT SWITCH CONNECTOR.
Measure resistance of harness between TCM
and chassis ground.
Connector & terminal
(B55) No. 12 — Chassis ground:
4 CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and brake
light switch.
2) Measure voltage between TCM and chas-
sis ground.
Connector & terminal
(B55) No. 12 (+) — Chassis ground (−):
5 CHECK INPUT SIGNAL FOR TCM.
Measure voltage between TCM and chassis
ground.
Connector & terminal
(B55) No. 12 (+) — Chassis ground (−):
6 CHECK POOR CONTACT.
Check poor contact in TCM connector.
Step
Is the resistance less than
1 Ω?
Is the resistance more than
1 MΩ?
Is the voltage less than 1 V
when releasing the brake
pedal?
Is the voltage more than 10
V when depressing the
brake pedal?
Is there poor contact in
TCM connector?
EN-223
Check Yes
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Repair poor con-
tact in TCM con-
nector.
Engine (Diagnostics)
No
Repair or replace
harness and con-
nector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
TCM and brake
light switch con-
nector
¼ Poor contact in
TCM connector
¼ Poor contact in
brake light switch
connector
Repair ground
short circuit in
harness between
TCM and brake
light switch con-
nector.
Adjust or replace
brake light switch.
<Ref. to LI-8,
STOP LIGHT
SWITCH,
INSPECTION,
Stop Light Sys-
tem.>
Adjust or replace
brake light switch.
<Ref. to LI-8,
STOP LIGHT
SWITCH,
INSPECTION,
Stop Light Sys-
tem.>
Replace TCM.
<Ref. to AT-49,
Transmission
Control Module
(DTC).>