Subaru 2009 IMPREZA, Service Manual

Page: 2033 / 3619

4AT(diag)-48
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step Check Yes No
1 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 connector and transmission connector.
Connector & terminal
(B55) No. 16 — (B11) No. 18:
(B55) No. 27 — (B11) No. 14:
Is the resistance less than 1
:
? Go to step 2 . Repair the open
circuit of harness
between TCM and
transmission con-
nector, and poor
contact of the con-
nector.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and transmission connector.
Connector & terminal
(B55) No. 16 — Chassis ground:
(B55) No. 27 — Chassis ground:
Is the resistance 1 M
:
or
more?
Go to step 3 . Repair the short
circuit of harness
between TCM and
chassis ground,
and poor contact of
connector.
3 CHECK FRONT VEHICLE SPEED SENSOR.
Measure the resistance between transmission
connector receptacle’s terminals.
Connector & terminal
(T4) No. 14 — No. 18:
Is the resistance 450 — 650
:
? Go to step 4 . Replace the front
vehicle speed sen-
sor. <Ref. to 4AT-
51, Front Vehicle
Speed Sensor.>
4 CHECK INPUT SIGNAL FOR TCM.
1) Connect all connectors.
2) Connect the Subaru Select Monitor to data
link connector.
3) Lift up the vehicle.
4) Turn the ignition switch to ON.
5) Run the Subaru Select Monitor.
6) Start the engine.
7) Slowly increase the vehicle speed to 60 km/
h (37 MPH).
NOTE:
The speed difference between front and rear
wheels lights the ABS warning light or the VDC
warning light, but this does not indicate a mal-
function. If the warning light is illuminated, clear
the memory of ABS or VDC after completing AT
control diagnosis. <Ref. to ABS(diag)-21, Clear
Memory Mode.>
8) Read the data of “Front Wheel Speed” using
Subaru Select Monitor. (Compare the speed-
ometer with Subaru Select Monitor indications.)
Does the speedometer indica-
tion increase as the Subaru
Select Monitor front wheel
speed data increases? Check the harness
of the front vehicle
speed sensor cir-
cuit, and repair the
defective part. Go to step 5 .
5 CHECK POOR CONTACT. Is there poor contact of front
vehicle speed sensor circuit? Repair the poor
contact. Replace the TCM.
<Ref. to 4AT-63,
Transmission Con-
trol Module
(TCM).>