Subaru Legacy 2003 Service Manual page 692

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 9 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN ECM AND
MAIN FUSE BOX CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 9 — Chassis ground:
Does the measured value exceed the spec-
ified value?
3 CHECK FUSE SBF-5.
Is fuse blown?
Value
10 V
1 MΩ
Fuse is brown.
EN(H4SO)-295
ENGINE (DIAGNOSTICS)
Yes
Repair poor con- Go to step 2.
tact in ECM con-
nector.
Go to step 3. Repair ground
short circuit in har-
ness between
ECM connector
and battery termi-
nal.
Replace fuse. Repair harness
and connector.
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