Subaru Legacy 2003 Service Manual page 456

ENGINE MALFUNCTION INDICATOR LAMP (MI)
Step
1 CHECK STATUS OF CHECK ENGINE MAL-
FUNCTION INDICATOR LAMP (MI).
1) Turn ignition switch to OFF.
2) Disconnect test mode connector.
3) Turn ignition switch to ON. (engine OFF)
Does the MI come on?
2 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Turn ignition switch to ON.
Does the MI come on?
3 CHECK HARNESS BETWEEN TEST MODE
CONNECTOR AND CHASSIS GROUND.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
test mode connector and chassis ground.
Connector & terminal
(B76) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied value?
4 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
5 CHECK HARNESS BETWEEN ECM AND
TEST MODE CONNECTOR.
1) Connect test mode connector.
2) Measure resistance of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 3 — Chassis ground:
Is the measured value less than the speci-
fied value?
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Value
MI illuminates.
MI illuminates.
1 Ω
There is poor contact.
1 Ω
There is poor contact.
EN(H4SO)-59
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the MI cir-
cuit. <Ref. to
EN(H4SO)-52,
CHECK ENGINE
MALFUNCTION
INDICATOR
LAMP (MI) DOES
NOT COME ON.,
Engine Malfunc-
tion Indicator
Lamp (MI).>
Repair ground Go to step 3.
short circuit in har-
ness between
combination meter
and ECM connec-
tor.
Go to step 4. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
test mode connec-
tor and chassis
ground
Repair poor con- Go to step 5.
tact in ECM con-
nector.
Go to step 6. Repair open circuit
in harness
between ECM and
test mode connec-
tor.
Repair poor con- Replace ECM.
tact in ECM con- <Ref. to
nector. FU(H4SO)-45,
Engine Control
Module.>
No