Subaru Impreza 2003 Service Manual page 1233

Step
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)
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.
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:
4 CHECK POOR CONTACT.
Check poor contact in ECM connector.
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
(B134) No. 5 — Chassis ground:
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
MALFUNCTION INDICATOR LIGHT
Does the malfunction indicator
light come on?
Does the malfunction indicator
light come on?
Is the resistance less than 1
Ω?
Is there poor contact in ECM
connector?
Is the resistance less than 1
Ω?
Is there poor contact in ECM
connector?
EN(H4DOTC)-57
Check
Go to step 2.
Repair the ground
short circuit in har-
ness between
combination meter
and ECM connec-
tor.
Go to step 4.
Repair the poor
contact in ECM
connector.
Go to step 6.
Repair the poor
contact in ECM
connector.
ENGINE (DIAGNOSTICS)
Yes No
Repair the mal-
function indicator
light circuit. <Ref.
to EN(H4DOTC)-
53, MALFUNC-
TION INDICA-
TOR LIGHT
DOES NOT
COME ON., Mal-
function Indicator
Light.>
Go to step 3.
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
test mode connec-
tor and chassis
ground
Go to step 5.
Repair the open
circuit in harness
between ECM and
test mode connec-
tor.
Replace the ECM.
<Ref. to
FU(H4DOTC)-49,
Engine Control
Module (ECM).>