Subaru 2002 IMPREZA Service Manual page 1645

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from TCM and
transmission.
3)Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 18 — (B11) No. 17:
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B54) No. 10 — (B11) No. 18:
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B54) No. 10 — Chassis ground:
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 18 — Chassis ground:
5 CHECK FRONT VEHICLE SPEED SENSOR.
Measure the resistance between transmission
connector receptacle's terminals.
Connector & terminal
(T4) No. 17 — No. 18:
6 PREPARE OSCILLOSCOPE.
7 PREPARE SUBARU SELECT MONITOR.
8 CHECK INPUT SIGNAL FOR TCM.
1)Connect all connectors.
2)Lift-up or raise the vehicle and place safety
stands.
NOTE:
On AWD models, 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.>
4)Measure the voltage between TCM connec-
tor terminals.
Connector & terminal
(B55) No. 18 (+) — (B54) No. 10 ( − − − − ):
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check
Is the resistance less than 1
Ω?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
Is the resistance between 450
and 650 Ω?
Do you have an oscilloscope? Go to step 9.
Do you have a Subaru Select
Monitor?
Is the voltage more than AC 1
V?
AT-59
Yes
Go to step 2. Repair the open
circuit in harness
between TCM and
transmission con-
nector.
Go to step 3. Repair the open
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
Go to step 4. Repair the short
circuit in harness
between TCM and
transmission con-
nector.
Go to step 5. Repair the short
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
Go to step 6. Replace the front
vehicle speed sen-
sor. <Ref. to AT-
32, Front Vehicle
Speed Sensor.>
Go to step 7.
Go to step 10. Go to step 8.
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 the front
vehicle speed sen-
sor circuit.
No