Subaru Legacy 2002 Service Manual page 1873

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Automatic Transmission (Diagnostics)
No.
9 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect connectors to TCM and transmis-
sion.
2) Connect Subaru Select Monitor to data link
connector.
3) Lift-up or raise the vehicle and place safety
stands.
NOTE:
On AWD models, raise all wheels off floor.
4) Turn ignition switch to ON and turn Subaru
Select Monitor switch to ON.
5) Start the engine.
6) Read data of vehicle speed using Subaru
Select Monitor.
¼ Compare speedometer with Subaru Select
Monitor indications.
¼ Vehicle speed is indicated in "km/h" or
"MPH".
7) Slowly increase vehicle speed to 60 km/h
or 37 MPH.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but
this indicates no malfunction. When AT control
diagnosis is finished, perform the ABS
memory clearance procedure of on-board
diagnostics system. <Ref. to ABS-21, Clear
Memory Mode.>
10 CHECK INPUT SIGNAL FOR TCM USING
OSCILLOSCOPE.
1) Connect connectors to TCM and transmis-
sion.
2) Lift-up or raise the vehicle and place safety
stands.
NOTE:
On AWD models, raise all wheels off floor.
3) Set oscilloscope to TCM connector termi-
nals.
Connector & terminal
Positive probe; (B55) No. 24
Ground; (B54) No. 19
4) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but
this indicates no malfunction. When AT control
diagnosis is finished, perform the ABS
memory clearance procedure of on-board
diagnostics system. <Ref. to ABS-21, Clear
Memory Mode.>
5) Measure signal voltage indicated on oscil-
loscope.
11 CHECK POOR CONTACT.
Step
Does the speedometer indi-
cation increase as the
Subaru Select Monitor data
increases?
Is the signal voltage more
than AC 1 V?
Is there poor contact in
rear vehicle speed sensor
circuit?
AT-104
Check Yes
Even if "POWER"
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tem-
porary poor con-
tact of the con-
nector or harness
may be the
cause. Repair
harness or con-
nector in the TCM
and transmission.
Even if "POWER"
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tem-
porary poor con-
tact of the con-
nector or harness
may be the
cause. Repair
harness or con-
nector in the TCM
and transmission.
Repair poor con-
tact.
No
Go to step 11.
Go to step 11.
Replace TCM.
<Ref. to AT-49,
Transmission
Control Module
(TCM).>