Subaru 2003 LEGACY Service Manual page 41

DIAGNOSTIC PROCEDURE FOR SELECT MONITOR COMMUNICATION
Step
1 CHECK SUBARU SELECT MONITOR POW-
ER SUPPLY CIRCUIT.
Measure voltage between data link connector
and chassis ground.
Connector & terminal
(B40) No. 1 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the specified
value?
2 CHECK SUBARU SELECT MONITOR
GROUND CIRCUIT.
Measure resistance of harness between data
link connector and chassis ground.
Connector & terminal
(B40) No. 12 — Chassis ground:
(B40) No. 13 — Chassis ground:
Is the measured value less than the specified
value?
3 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn ignition switch to ON.
2) Using the select monitor, check whether
communication to engine systems can be
executed normally.
Are the name and year of the system dis-
played on the select monitor?
4 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn ignition switch to OFF.
2) Disconnect TCM connector.
3) Check whether communication to engine
systems can be executed normally.
Are the name and year of the system dis-
played on the select monitor?
5 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn ignition switch to OFF.
2) Connect TCM connector.
3) Disconnect ECM connector.
4) Check whether communication to transmis-
sion systems can be executed normally.
Are the name and year of the system dis-
played on the select monitor?
6 CHECK HARNESS CONNECTOR BETWEEN
EACH CONTROL MODULE AND DATA LINK
CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect TCM and ECM connectors.
3) Measure resistance between data link con-
nector and chassis ground.
Connector & terminal
(B40) No. 10 — Chassis ground:
(B40) No. 6 — Chassis ground:
Does the measured value exceed the spec-
ified value?
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Value
10 V
1 Ω
Name and year are displayed. Go to step 6.
Name and year are displayed. Go to step 8.
Name and year are displayed. Inspect ECM.
1 MΩ
AT-39
Yes
Go to step 2. Repair harness
and connector
between battery
and data link con-
nector, and poor
contact in cou-
pling connector.
Go to step 3. Repair open circuit
in harness
between data link
connector and
ground terminal,
and poor contact
in coupling con-
nector.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7. Repair harness
and connector
between each
control module
and data link con-
nector.
No