Subaru 2004 LEGACY Service Manual page 66

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B134) No. 26 — Chassis ground:
(B134) No. 33 — Chassis ground:
Check
Is the resistance more than 1
MΩ?
EN(H6DO)(diag)-135
ENGINE (DIAGNOSTICS)
Yes
Replace the front Repair the ground
oxygen (A/F) sen- short circuit in har-
sor. <Ref. to ness between
FU(H6DO)-30, ECM and front
Front Oxygen (A/ oxygen (A/F) sen-
F) Sensor.> sor connector.
No