Subaru Impreza 2003 Service Manual page 1402

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK HARNESS BETWEEN TCM AND
CCM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connectors from TCM and
CCM.
3)Measure the resistance of harness between
TCM and CCM connector.
Connector & terminal
(B55) No. 22 — (B94) No. 3:
2 CHECK HARNESS BETWEEN TCM AND
CCM CONNECTOR.
Measure the resistance of harness between
TCM and chassis ground.
Connector & terminal
(B55) No. 22 — Chassis ground:
3 CHECK INPUT SIGNAL FOR TCM.
1)Connect the connector to TCM and CCM.
2)Lift-up the vehicle or set the vehicle on free
rollers.
CAUTION:
Raise all wheels off ground.
3)Start the engine.
4)Turn the cruise control main switch to ON.
5)Move the select lever to "D" range and slowly
increase vehicle speed to 50 km/h (31 MPH).
6)Turn the cruise control command switch to
ON.
7)Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 22 (+) — Chassis ground ( − − − − ):
4 CHECK POOR CONTACT.
Check poor contact in TCM connector.
Check
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the voltage less than 1 V?
Is there poor contact in TCM
connector?
EN(H4DOTC)-226
Yes
Go to step 2. Repair the open
circuit in harness
between TCM and
CCM connector.
Go to step 3. Repair the short
circuit in harness
between TCM and
CCM connector.
Go to step 4. Check the cruise
control command
switch circuit.
<Ref. to CC-7,
INSPECTION,
Cruise Control
Command
Switch.>
Repair the poor Replace the TCM.
contact in TCM <Ref. to 4AT-70,
connector. Transmission Con-
trol Module
(TCM).>
No