Subaru 2004 LEGACY Service Manual page 68

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 ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 (+) — Chassis ground (
(B134) No. 33 (+) — Chassis ground (
Check
Is the voltage more than 8 V?
−
):
−
):
EN(H6DO)(diag)-137
ENGINE (DIAGNOSTICS)
Yes
Replace the front Repair the battery
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