Subaru IMPREZA 2002 Service Manual page 592

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
I
ENGINE IDIAGNOSTICS)
Step
CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (AIF) SENSOR.
Measure the resistance between ECM and
chassis ground.
5
Connector & terminals
(8136) No. 6
-
Chassis ground:
(8136) No. 7
-
Chassis ground:
(8136) No. 19
-
Chassis ground:
(8136) No.
20
-
Chassis ground:
6
CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items.
*Loose installation of portions
*Damage (crack, hole etc.) of parts
*Looseness of front oxygen (NF) sensor
*Looseness and ill fitting of parts between front
oxygen (NF) sensor and rear oxygen sensor
Check
Is the resistance more than 1
MQ?
Is there a fault in exhaust sys-
tem?
Yes
; o to step
6 .
3epair or replace
sulty parts.
No
Repair ground
short circuit
between ECM and
front oxygen (NF)
sensor.
Replace the front
oxygen (NF) sen-
sor. <Ref. to
Front Oxygen
(A/
F) Sensor.>
FU(S0HC)-43,
EN(S0HC)-268