4AT(diag)-29
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Diagnostic Procedure for Subaru Select Monitor Communication
10
CHECK INSTALLATION OF TRANSMISSION
HARNESS CONNECTOR.
Is the transmission harness
connector connected to bulk-
head harness connector?
Go to step 11.
Connect the bulk-
head harness con-
nector to
transmission har-
ness connector.
11
CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in control
module power supply and data
link connector?
Repair the poor
contact.
Go to step 12.
12
CHECK POWER SUPPLY OF TCM.
1) Disconnect the connector from TCM.
2) Turn the ignition switch to ON.
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B55) No. 27 (+) — Chassis ground (
−
):
(B55) No. 28 (+) — Chassis ground (
−
):
(B55) No. 29 (+) — Chassis ground (
−
):
Is the voltage 10 — 13 V?
Go to step 14.
Go to step 13.
13
CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse M/B (No. 12).
Is the fuse M/B (No. 12) blown
out?
Replace the fuse
M/B (No. 12). If the
replaced fuse M/B
(No. 12) has blown
out easily, repair
the short circuit of
harness between
fuse M/B (No. 12)
and TCM.
Repair the open
circuit of harness
between fuse M/B
(No. 12) and TCM,
or fuse M/B (No.
12) and battery,
and poor contact
in connector.
14
CHECK IGNITION POWER SUPPLY CIR-
CUIT.
1) Turn the ignition switch to ON (engine
OFF).
2) Measure the ignition power supply voltage
between TCM connector and chassis ground.
Connector & terminal
(B55) No. 21 (+) — Chassis ground (
−
):
(B55) No. 31 (+) — Chassis ground (
−
):
Is the voltage 10 — 13 V?
Go to step 16.
Go to step 15.
15
CHECK FUSE.
Remove the fuse F/B (No. 12).
Is the fuse F/B (No. 12) blown
out?
Replace the fuse
F/B (No. 12). If the
replaced fuse F/B
(No. 12) has blown
out easily, repair
the short circuit of
harness between
fuse F/B (No. 12)
and TCM.
Repair the open
circuit of harness
between fuse F/B
(No. 12) and TCM,
or fuse F/B (No.
12) and battery,
and poor contact
in connector.
16
CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
transmission.
3) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B54) No. 8 — (B11) No. 19:
(B54) No. 17 — (B11) No. 19:
(B55) No. 2 — (B11) No. 20:
(B55) No. 3 — (B11) No. 20:
Is the resistance less than 1
Ω?
Go to step 17.
Repair the open
circuit of harness
between TCM and
transmission har-
ness connector,
and poor contact
in connector.
Step
Check
Yes
No