Subaru Forester 2004 Service Manual page 107

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness between
ECM and front oxygen (A/F) sensor connector.
Connector & terminal
(B134) No. 26 — Chassis ground:
(B134) No. 33 — Chassis ground:
Check
Is the resistance more than 1
MΩ?
EN(H4DOTC 2.5)-106
Yes
Replace the front Repair ground
oxygen (A/F) sen- short circuit in har-
sor. <Ref. to ness between
FU(H4DOTC 2.5)- ECM and front
36, Front Oxygen oxygen (A/F) sen-
(A/F) Sensor.> sor connector.
No