Subaru 2002 IMPREZA Service Manual page 409

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
I
ENGINE (DIAGNOSTICS)
Step
CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(8135) No. 4
-
Chassis ground:
! CHECK KNOCK SENSOR.
1)Disconnect the connector from knock sensor.
Check
Is the resistance less than 400
kR?
Is the resistance less than
400
kR?
I CHECK INPUT SIGNAL FOR ECM.
1)Connect the connectors to ECM and knock
sensor.
2)Turn the ignition switch to ON.
3)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(6135) No. 4 (+)
-
Chassis ground (-):
Replace the knock
sensor. <Ref. to
FU(D0HC
Knock Sensor.>
TURBO)-32,
Even if MIL lights
up, the circuit has
returned to a nor-
s the voltage more than 2 V?
Repair ground
short circuit in har
ness between
knock sensor con-
nector and ECM
connector.
NOTE:
The harness be
tween both con
nectors i!
shielded. Repai
short circuit of har
ness together witt
shield.
Repair poor con-
tact in ECM con-
nector.
EN(D0HC TURBO)-185