Subaru Legacy 2003 Service Manual page 471

DIAGNOSTICS FOR ENGINE STARTING FAILURE
ENGINE (DIAGNOSTICS)
6 CHECK INPUT SIGNAL FOR IGNITION COIL
& IGNITOR ASSEMBLY.
1) Connect connector to ignition coil & ignitor
assembly.
2) Check if voltage varies synchronously with
engine speed when cranking, while moni-
toring voltage between ignition coil & ignitor
assembly connector and engine ground.
Connector & terminal
(E12) No. 1 (+) — Engine ground (–):
(E12) No. 4 (+) — Engine ground (–):
Does the measured value exceed the spec-
ified value?
7 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSEMBLY CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Disconnect connector from ignition coil &
ignitor assembly.
4) Measure resistance of harness between
ECM and ignition coil & ignitor assembly
connector.
Connector & terminal
(B134) No. 33 — (E12) No. 1:
(B134) No. 32 — (E12) No. 4:
Is the measured value less than the speci-
fied value?
8 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSEMBLY CON-
NECTOR.
Measure resistance of harness between ECM
and engine ground.
Connector & terminal:
(B134) No. 32 — Engine ground:
(B134) No. 33 — Engine ground:
Does the measured value exceed the specified
value?
9 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Step Value
10 V
1 Ω
1 MΩ
There is poor contact.
EN(H4SO)-74
Yes
Go to step 7. Replace ignition
coil & ignitor
assembly. <Ref. to
IG(H4SO)-8, Igni-
tion Coil and Igni-
tor Assembly.>
Go to step 8. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and ignition
coil & ignitor
assembly connec-
tor
• Poor contact in
coupling connector
Go to step 9. Repair ground
short circuit in har-
ness between
ECM and ignition
coil & ignitor
assembly connec-
tor.
Repair poor con- Check fuel pump
tact in ECM con- circuit. <Ref. to
nector. EN(H4SO)-76,
FUEL PUMP CIR-
CUIT, Diagnostics
for Engine Start-
ing Failure.>
No