Subaru Impreza 2004 - Page 362

EN(H4SO)(diag)-56
ENGINE (DIAGNOSTICS)
Malfunction Indicator Light
Step Check Yes No
1 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1)Turn the ignition switch to OFF.
2)Disconnect the test mode connector.
3)Turn the ignition switch to ON. (engine OFF)
Dose the malfunction indicator
light illuminate?
Go to step 2. Repair the mal-
function indicator
light circuit. <Ref.
to
EN(H4SO)(diag)-
52, MALFUNC-
TION INDICA-
TOR LIGHT
DOES NOT
COME ON., Mal-
function Indicator
Light.>
2 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Turn the ignition switch to ON.
Dose the malfunction indicator
light illuminate?
Repair ground
short circuit in har-
ness between
combination meter
and ECM connec-
tor.
Go to step 3.
3 CHECK HARNESS BETWEEN TEST MODE
CONNECTOR AND CHASSIS GROUND.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
test mode connector and chassis ground.
Connector & terminal
(B76) No. 1 — Chassis ground:
Is the resistance less than 1
Ω?
Go to step 4. Repair harness
and connector.
N
O
TE:
In this case, repair
the following:
• Open circuit in
harness between
test mode connec-
tor and chassis
ground
4 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM
connector?
Repair poor con-
tact in ECM con-
nector.
Go to step 5.
5 CHECK HARNESS BETWEEN ECM AND
TEST MODE CONNECTOR.
1)Connect the test mode connector.
2)Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 3 — Chassis ground:
Is the resistance less than 1
Ω?
Go to step 6. Repair open circuit
in harness
between ECM and
test mode connec-
tor.
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM
connector?
Repair poor con-
tact in ECM con-
nector.
Replace the ECM.
<Ref. to
FU(H4SO)-47,
Engine Control
Module (ECM).>