Subaru Legacy 2002 Service Manual page 662

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 6 — Chassis ground:
(B136) No. 7 — Chassis ground:
(B136) No. 19 — Chassis ground:
(B136) No. 20 — Chassis ground:
Step
Is the resistance more than
10 Ω?
EN-145
Check Yes
Replace front oxy-
gen (A/F) sensor.
<Ref. to FU-47,
Front Oxygen
(A/F) Sensor.>
Engine (Diagnostics)
No
Repair ground
short circuit in
harness between
ECM and front
oxygen (A/F) sen-
sor connector.