Subaru Legacy 2004 Service Manual page 1382

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 connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 — Chassis ground:
(B134) No. 33 — Chassis ground:
2 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
Measure the resistance of harness between
ECM connectors.
Connector & terminal
(B134) No. 26 — (B134) No. 33:
Check
Is the resistance more than 1
M'?
Is the resistance more than 1
M'?
EN(H4DOTC)(diag)-93
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the ground
short circuit in har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
Replace the front Repair harness
oxygen (A/F) sen- short in harness
sor. <Ref. to between ECM and
FU(H4DOTC)-33, front oxygen (A/F)
Front Oxygen (A/ sensor connector.
F) Sensor.>
No