Subaru Forester 2004 Service Manual page 167

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK HARNESS BETWEEN ECM AND
TCM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from TCM.
4) Measure the resistance between ECM and
TCM connectors.
Connector & terminal
(B137) No. 18 — (B55) No. 3:
(B137) No. 26 — (B55) No. 12:
2 CHECK HARNESS BETWEEN ECM AND
TCM.
Measure the resistance between ECM connec-
tor and chassis ground.
Connector & terminal
(B137) No. 18 — Chassis ground:
(B137) No. 26 — Chassis ground:
3 CHECK HARNESS BETWEEN ECM AND
TCM.
Check the resistance between ECM connec-
tors.
Connector & terminal
(B137) No. 18 — (B137) No. 26:
4 CHECK AT SYSTEM CONDITION.
Perform the diagnosis for AT using Subaru
Select Monitor.
Check
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
Is DTC P1718 displayed?
EN(H4DOTC 2.5)-166
Yes
Go to step 2. Repair the harness
and connector.
Go to step 3. Repair the harness
and connector.
Go to step 4. Repair the harness
and connector.
Check AT system. Replace the ECM.
No