Subaru IMPREZA GD 2007 Series Manual page 172

asieps_tobira_IM_US.book 63 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Step
1 CHECK MAIN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the main relay.
3) Using the lead wire, connect the battery (+)
to the terminal No. 1 of main relay, and the bat-
tery (–) to the terminal No. 2.
4) Measure the resistance between main relay
terminals.
Terminals
No. 3 — No. 6:
No. 4 — No. 5:
2 CHECK GROUND CIRCUIT FOR ECM.
1) Disconnect the connectors from the ECM.
2) Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B134) No. 5 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 3 — Chassis ground:
(B137) No. 7 — Chassis ground:
3 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
(B135) No. 5 (+) — Chassis ground (–):
(B135) No. 27 (+) — Chassis ground (–):
4 CHECK INPUT VOLTAGE OF MAIN RELAY.
Measure the voltage between main relay con-
nector and chassis ground.
Connector & terminal
(B47) No. 1 (+) — Chassis ground (–):
(B47) No. 5 (+) — Chassis ground (–):
(B47) No. 6 (+) — Chassis ground (–):
5 CHECK INPUT VOLTAGE OF ECM.
1) Connect the main relay connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
(B135) No. 2 (+) — Chassis ground (–):
(B134) No. 7 (+) — Chassis ground (–):
(B136) No. 24 (+) — Chassis ground (–):
Diagnostics for Engine Starting Failure
Is the resistance less than 10
Ω?
Is the resistance less than 5 Ω? Go to step 3.
Is the voltage 10 V or more?
Is the voltage 10 V or more?
Is the voltage 10 V or more?
EN(H4SO)(diag)-63
ENGINE (DIAGNOSTICS)
Check Yes
Go to step 2.
Go to step 4.
Go to step 5.
Check the ignition
control system.
<Ref. to
EN(H4SO)(diag)-
64, IGNITION
CONTROL SYS-
TEM, Diagnostics
for Engine Starting
Failure.>
No
Replace the main
relay.
Repair the open
circuit of harness
or poor contact in
the connector
between ECM con-
nector and engine
grounding termi-
nal.
Repair the open or
ground short circuit
of power supply
circuit.
Repair the open or
ground short circuit
of harness of
power supply cir-
cuit.
Repair the open or
ground short circuit
of harness
between ECM con-
nector and main
relay connector.