Subaru Legacy 2005 Service Manual page 1315

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B135) No. 4 — Chassis ground:
(B135) No. 1 — Chassis ground:
2 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 2 (+) — Chassis ground (
Check
Is the resistance less than 5
Ω?
Is the voltage more than 10 V? Repair the battery
−
):
EN(H4DOTC)(diag)-75
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ECM and engine
ground cable
• Poor contact in
ECM connector
• Poor contact in
coupling connector
Repair the poor
short circuit of har- connection in ECM
ness between connector.
ECM and rear oxy-
gen sensor.
No