Subaru 2009 IMPREZA Service Manual page 2040

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
6 CHECK OUTPUT SIGNAL OF TCM.
1) Return the engine speed to idle.
2) Set the select lever to "N" range.
3) Read the data of "Lock Up Duty Ratio" using
Subaru Select Monitor.
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.>
7 CHECK POOR CONTACT.
8 CHECK LOCK-UP DUTY SOLENOID (IN
TRANSMISSION).
1) Disconnect the transmission connector.
2) Drain the automatic transmission fluid.
CAUTION:
Do not drain ATF until it cools down.
3) Remove the oil pan.
4) Disconnect the connector from the control
valve body.
5) Measure the resistance between lock-up
duty solenoid and transmission ground.
Connector & terminal
(AT2) No. 6 — Transmission ground:
9 CHECK HARNESS CONNECTOR BETWEEN
LOCK-UP DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
lock-up duty solenoid and transmission connec-
tor.
Connector & terminal
(T4) No. 12 — (AT2) No. 6:
10 CHECK HARNESS CONNECTOR BETWEEN
LOCK-UP DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 12 — Transmission ground:
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check
Is the measured value 0%?
Is there poor contact of lock-up
duty solenoid circuit?
Is the resistance 2.0 — 6.0 ? Go to step 9.
Is the resistance less than 1 ? Go to step 10.
Is the resistance 1 M or
more?
4AT(diag)-55
Yes No
Check the har- Go to step 7.
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).>
Replace the con-
trol valve body.
<Ref. to 4AT-58,
Control Valve
Body.>
Repair the open
circuit of harness
between TCM and
transmission con-
nector.
Check the har- Repair the short
nesses or connec- circuit of harness
tors between lock- between lock-up
up duty solenoid duty solenoid and
and transmission, transmission con-
and repair the nector.
defective part.