Subaru 2009 IMPREZA Service Manual page 2051

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmission
and TCM.
3) Measure the resistance of harness between
TCM connector and transmission connector.
Connector & terminal
(B54) No. 5 — (B11) No. 6:
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND CHASSIS GROUND.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 5 — Chassis ground:
3 CHECK LOW & REVERSE DUTY SOLENOID.
Measure the resistance between transmission
connector terminals.
Connector & terminal
(T4) No. 6 — No. 20:
4 CHECK OUTPUT SIGNAL OF TCM.
1) Connect all connectors.
2) Connect the Subaru Select Monitor to data
link connector.
3) Start the engine.
4) Run the Subaru Select Monitor.
5) Warm up the transmission until the ATF
temperature exceeds approximately 80°C
(176°F).
6) Stop the engine.
7) Turn the ignition switch to ON.
8) Set the select lever to "N" range.
9) Read the data of "L&R B Duty" using Subaru
Select Monitor.
5 CHECK OUTPUT SIGNAL OF TCM.
1) Lift up the vehicle.
2) Shift the select lever to manual mode, and
then hold it on 1st. Slowly increase the vehicle
speed up to 15 km/h (9 MPH), and then return
the accelerator pedal.
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.> <Ref. to VDC(diag)-24, Clear
Memory Mode.>
3) Read the data of "L&R B Duty".
6 CHECK POOR CONTACT.
Check
Is the resistance less than 1 ? Go to step 2.
Is the resistance 1 M or
more?
Is the resistance 2.0 — 6.0 ? Go to step 4.
Is the measured value 100%?
Is the measured value 55%?
Is there poor contact of the low
& reverse duty solenoid circuit?
4AT(diag)-66
Yes No
Repair the open
circuit of harness
between TCM and
transmission con-
nector.
Go to step 3. Repair the short
circuit of harness
between TCM and
transmission con-
nector.
Go to step 7.
Go to step 5. Go to step 6.
Check the har- Go to step 6.
nesses or connec-
tors between TCM
and transmission,
and repair the
defective part.
Repair the poor Replace the TCM.
contact. <Ref. to 4AT-63,
Transmission Con-
trol Module
(TCM).>