Subaru Impreza 2003, Service Manual

Page: 478 / 3610

EN(H4SO)-66
ENGINE (DIAGNOSTICS)
DIAGNOSTICS FOR ENGINE STARTING FAILURE
2 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSY.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ignition coil &
ignitor ASSY.
3)Turn the ignition switch to ON.
4)Measure the power supply voltage between
ignition coil & ignitor ASSY connector and
engine ground.
Connector & terminal
1.6 L: (E12) No. 1 (+) — Engine ground
(
−−−−
):
2.0 L: (E12) No. 2 (+) — Engine ground
(
−−−−
):
Is the voltage more than 10 V? Go to step 3. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor ASSY, and
ignition switch
connector
• Poor contact in
coupling connec-
tors
3 CHECK HARNESS OF IGNITION COIL & IG-
NITOR ASSY GROUND CIRCUIT.
1)Turn the ignition switch to OFF.
2)Measure the resistance between ignition coil
& ignitor ASSY connector and engine ground.
Connector & terminal
(E12) No. 3 — Engine ground:
Is the resistance less than 5
Ω
?
Go to step 4. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor ASSY connec-
tor and engine
grounding terminal
4 CHECK IGNITION COIL & IGNITOR ASSY.
1)Remove the spark plug cords.
2)Measure the resistance between spark plug
cord contact portions to check secondary coil.
Terminals
No. 1 — No. 2:
No. 3 — No. 4:
Is the resistance 10 — 15 k
Ω
? Go to step 5. Replace the igni-
tion coil & ignitor
ASSY. <Ref. to
IG(H4SO)-8, Igni-
tion Coil & Ignitor
ASSY.>
5 CHECK INPUT SIGNAL FOR IGNITION COIL
& IGNITOR ASSY.
1)Connect the connector to ignition coil & igni-
tor ASSY.
2)Check if voltage varies synchronously with
engine speed when cranking, while monitoring
voltage between ignition coil & ignitor ASSY
connector and engine ground.
Connector & terminal
1.6 L: (E12) No. 4 (+) — Engine ground
(–):
2.0 L: (E12) No. 1 (+) — Engine ground
(–):
1.6 L: (E12) No. 2 (+) — Engine ground
(–):
2.0 L: (E12) No. 4 (+) — Engine ground
(–):
Is the voltage more than 10 V? Go to step 6. Replace the igni-
tion coil & ignitor
ASSY. <Ref. to
IG(H4SO)-8, Igni-
tion Coil & Ignitor
ASSY.>
Step Check Yes No