Subaru Legacy 2003 Service Manual page 2076

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL FOR ECM.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 10 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN ECM AND
MAIN FUSE BOX CONNECTOR.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B137) No. 10 — Chassis ground:
Does the measured value exceed the spec-
ified value?
3 CHECK FUSE SBF-5.
Is the fuse blown?
Value
10 V
1 MΩ
Fuse is blown-out.
EN(H4DOSTC)-237
ENGINE (DIAGNOSTICS)
Yes
Repair the poor Go to step 2.
contact in ECM
connector.
Go to step 3. Repair the ground
short circuit in har-
ness between
ECM connector
and battery termi-
nal.
Replace the fuse. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and battery
• Poor contact in
ECM connector
• Poor contact in
battery terminal
No