Subaru 2002 IMPREZA Service Manual page 505

DIAGNOSTICS FOR ENGINE STARTING FAILURE
Step
2 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSEMBLY.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ignition coil &
ignitor assembly.
3)Turn the ignition switch to ON.
4)Measure the power supply voltage between
ignition coil & ignitor assembly connector and
engine ground.
Connector & terminal
• 2.0 L and 2.5 L
(E12) No. 2 (+) — Engine ground ( − − − − ):
• 1.6 L
(E12) No. 1 (+) — Engine ground ( − − − − ):
3 CHECK HARNESS OF IGNITION COIL & IG-
NITOR ASSEMBLY GROUND CIRCUIT.
1)Turn the ignition switch to OFF.
2)Measure the resistance between ignition coil
& ignitor assembly connector and engine
ground.
Connector & terminal
(E12) No. 3 — Engine ground:
4 CHECK IGNITION COIL & IGNITOR ASSEM-
BLY.
1)Remove the spark plug cords.
2)Measure the resistance between spark plug
cord contact portions to check secondary coil.
Terminals
• 2.0 L and 2.5 L
No. 1 — No. 2:
• 1.6 L
No. 4 — No. 1:
5 CHECK IGNITION COIL & IGNITOR ASSEM-
BLY.
Measure the resistance between spark plug
cord contact portions to check secondary coil.
Terminals
• 2.0 L and 2.5 L
No. 3 — No. 4:
• 1.6 L
No. 3 — No. 2:
6 CHECK INPUT SIGNAL FOR IGNITION COIL
& IGNITOR ASSEMBLY.
1)Connect the connector to ignition coil & igni-
tor assembly.
2)Check if the voltage varies synchronously
with engine speed when cranking, while moni-
toring voltage between ignition coil & ignitor
assembly connector and engine ground.
Connector & terminal
• 2.0 L and 2.5 L
(E12) No. 1 (+) — Engine ground (–):
• 1.6 L
(E12) No. 4 (+) — Engine ground ( − − − − ):
Check
Is the voltage more than 10 V? Go to step 3.
Is the resistance between less
than 5 Ω?
Is the resistance between 10
and 15 kΩ?
Is the resistance between 10
and 15 kΩ?
Is the voltage more than 10 V? Go to step 7.
EN-73
ENGINE (DIAGNOSTICS)
Yes
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor assembly, and
ignition switch
connector
• Poor contact in
coupling connec-
tors (B22)
Go to step 4. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor assembly con-
nector and engine
grounding terminal
Go to step 5. Replace the igni-
tion coil & ignitor
assembly. <Ref. to
IG-8, Ignition Coil
and Ignitor Assem-
bly.>
Go to step 6. Replace the igni-
tion coil & ignitor
assembly. <Ref. to
IG-8, Ignition Coil
and Ignitor Assem-
bly.>
Replace the igni-
tion coil & ignitor
assembly. <Ref. to
IG-8, Ignition Coil
and Ignitor Assem-
bly.>
No