Subaru Legacy 2005 Service Manual page 1344

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
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.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 26 — (B18) No. 1:
(B134) No. 33 — (B18) No. 2:
Check
Is the resistance less than 1
Ω?
EN(H4DOTC)(diag)-104
Yes
Replace the front Repair the open
oxygen (A/F) sen- circuit of harness
sor. <Ref. to between ECM and
FU(H4DOTC)-32, front oxygen (A/F)
Front Oxygen (A/ sensor connector.
F) Sensor.>
No