Subaru 2002 IMPREZA Service Manual page 1221

DIAGNOSTICS FOR ENGINE STARTING FAILURE
Step
3 CHECK INPUT SIGNAL FOR STARTER MO-
TOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from starter motor.
3)Turn the ignition switch to START.
4)Measure the power supply voltage between
starter motor connector terminal and engine
ground.
Connector & terminal
(B14) No. 1 (+) — Engine ground ( − − − − ):
4 CHECK GROUND CIRCUIT OF STARTER
MOTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the terminal from starter motor.
3)Measure the resistance of ground cable
between ground cable terminal and engine
ground.
5 CHECK HARNESS BETWEEN ECM AND
STARTER MOTOR CIRCUIT.
1)Turn the ignition switch to OFF.
2)Measure the resistance between starter
motor and ECM.
Connector & terminal
(B14) No. 1 — Engine ground:
6 CHECK HARNESS BETWEEN ECM AND
STARTER MOTOR CIRCUIT.
1)Turn the ignition switch to START.
2)Measure the resistance of fuse.
Connector & terminal
(B14) No. 1 — Engine ground:
7 CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1)Ignition the switch to OFF.
2)Disconnect the connector from ignition
switch.
3)Measure the power supply voltage between
ignition switch connector and chassis ground.
Connector & terminal
(B72) No. 1 (+) — Chassis ground ( − − − − ):
8 CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1)Connect the connector to ignition switch.
2)Turn the ignition switch to START.
3)Measure the voltage between ignition switch
and chassis ground.
Connector & terminal
(B72) No. 3 (+) — Chassis ground ( − − − − ):
9 CHECK POOR CONTACT.
Check poor contact in ignition switch connec-
tor.
Check
Is the voltage more than 10 V? Go to step 4.
Is the resistance less than 5
Ω?
Is the resistance less than 1
Ω?
Is the resistance less than 1
Ω?
Is the voltage more than 10 V? Go to step 8.
Is the voltage more than 10 V? Repair the open
Is there poor contact in ignition
switch connector?
EN(TURBO)-61
ENGINE (DIAGNOSTICS)
Yes
Go to step 5.
Check the starter Repair the open
motor. <Ref. to circuit of ground
SC-5, Starter.> cable.
Repair the ground Go to step 6.
short circuit.
Go to step 7. Repair the ground
short circuit.
Repair the open
circuit in harness
between ignition
switch and battery.
Go to step 9.
circuit between
ignition switch and
starter motor cir-
cuit.
Repair the poor Replace the igni-
contact in ignition tion switch.
switch connector.
No