Subaru 2003 LEGACY Service Manual page 63

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect all connectors.
2) Lift-up or raise the vehicle and place safety
stands.
NOTE:
Raise all wheels off floor.
3) 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 di-
agnosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. <Ref. to ABS-22, Clear Memory
Mode.> or <Ref. to VDC-25, Clear Memory
Mode.>
4) Measure voltage between TCM connector
terminals.
Connector & terminal
(B55) No. 18 (+) — (B54) No. 10 ( − − − − ):
Does the measured value exceed the spec-
ified value?
9 CHECK FRONT VEHICLE SPEED SENSOR
USING OSCILLOSCOPE.
1) Connect all connectors.
2) Lift-up the vehicle and place safety stand.
NOTE:
Raise all wheels off ground.
3) Set oscilloscope to TCM connector termi-
nals.
Connector & terminal
Positive probe; (B55) No. 18
Ground; (B54) No. 10
4) Start the engine, and drive the wheels
slowly.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunctions. When AT control di-
agnosis is finished, perform the ABS memory
clearance procedure of self-diagnosis system.
<Ref. to ABS-22, Clear Memory Mode.> or
<Ref. to VDC-25, Clear Memory Mode.>
5) Measure signal voltage indicated on oscillo-
scope.
Does the measured value exceed the spec-
ified value?
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Value
AC 1 V
AC 1 V
AT-61
Yes
Even if "POWER" Go to step 11.
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor connec-
tor or harness may
be the case.
Repair harness or
connector in the
front vehicle speed
sensor circuit.
Even if "POWER" Go to step 11.
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor connec-
tor or harness may
be the case.
Repair harness or
connector in the
front vehicle speed
sensor circuit.
No