Subaru 2002 IMPREZA Service Manual page 1646

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step
9 CHECK FRONT VEHICLE SPEED SENSOR
USING OSCILLOSCOPE.
1)Connect all connectors.
2)Lift-up the vehicle and place safety stand.
NOTE:
On AWD models, raise all wheels off ground.
3)Set the oscilloscope to TCM connector termi-
nals.
Connector & terminal
Positive probe; (B55) No. 18
Earth lead; (B54) No. 10
1)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.>
2)Measure the signal voltage indicated on
oscilloscope.
10 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1)Connect all connectors.
2)Connect the 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 the ignition switch to ON and turn Sub-
aru Select Monitor switch to ON.
5)Start the engine.
6)Read the data of vehicle speed using Subaru
Select Monitor.
•Compare the speedometer with Subaru
Select Monitor indications.
•Vehicle speed is indicated in "km/h" or "MPH".
7)Slowly increase the 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 di-
agnosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. <Ref. to ABS-22, Clear Memory
Mode.>
11 CHECK POOR CONTACT.
Check
Is the voltage more than AC 4
V?
Does the speedometer indica-
tion increase as Subaru Select
Monitor data increases?
Is there poor contact in front
vehicle speed sensor circuit?
AT-60
Yes
Even if the Go to step 11.
POWER indicator
lights up, the cir-
cuit has returned
to a normal condi-
tion at this time. A
temporary poor
contact or har-
ness may be the
cause. Repair the
harness or con-
nector in front
vehicle speed sen-
sor circuit.
Even if the Go to step 11.
POWER indicator
lights up, the cir-
cuit has returned
to a normal condi-
tion at this time. A
temporary poor
connector or har-
ness may be the
cause. Repair the
harness or con-
nector in front
vehicle speed sen-
sor circuit.
Repair the poor Replace the TCM.
contact. <Ref. to AT-46,
Transmission Con-
trol Module
(TCM).>
No