Subaru Legacy 2005 Service Manual page 2232

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
ECM.
3) Measure the resistance of harness
between TCM and ECM.
Connector & terminal
2.5 L EK and 2.5 L K4 model
(B54) No. 13 — (B134) No. 23:
Except for 2.5 L EK and 2.5 L K4 model
(B54) No. 13 — (B135) No. 27:
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 13 — Chassis ground:
3 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and ECM.
2) Connect the Subaru Select Monitor to data
link connector.
3) Start the engine, and turn the Subaru
Select Monitor power switch to ON.
4) Run the engine at idle.
5) Read the data of engine speed using Sub-
aru Select Monitor.
• Display shows engine speed signal value
sent from ECM.
4 CHECK POOR CONTACT.
5 CONFIRM DTC P0725.
Replace the ECM with a new one.
Check
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the revolution value same as
the tachometer reading shown
on the combination meter?
Is there poor contact in engine
speed signal circuit?
Does the DTC appear again,
after the memory has been
cleared?
4AT(diag)-60
Yes
Go to step 2. Repair the open
circuit of harness
between TCM and
ECM connector.
Go to step 3. Repair the short
circuit of harness
between TCM and
ECM connector.
Even if the SPORT Go to step 4.
indicator light is
blinking, the cir-
cuit has returned
to normal condi-
tion at this time. A
temporary poor
contact of connec-
tor or harness may
be the cause.
Repair the har-
ness or connector
in the TCM and
ECM.
Repair the poor Go to step 5.
contact.
Replace the TCM. Replace the ECM.
<Ref. to 4AT-66, <Ref. to FU(H4SO
Transmission Con- 2.0)-34, Engine
trol Module Control Module
(TCM).> (ECM).>
No