Subaru 2002 IMPREZA Service Manual page 579

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
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
(B136) No. 6 — Chassis ground:
(B136) No. 7 — Chassis ground:
(B136) No. 19 — Chassis ground:
(B136) No. 20 — Chassis ground:
Check
Is the resistance more than 10
Ω?
EN-147
ENGINE (DIAGNOSTICS)
Yes
Replace the front Repair the ground
oxygen (A/F) sen- short circuit in har-
sor. <Ref. to FU- ness between
47, Front Oxygen ECM and front
(A/F) Sensor.> oxygen (A/F) sen-
sor connector.
No