Subaru Legacy 2003 Service Manual page 1896

DIAGNOSTICS FOR ENGINE STARTING FAILURE
Step
1 CHECK MAIN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the main relay.
3) Connect the battery to main relay terminals
No. 1 and No. 2.
4) Measure the resistance between main relay
terminals.
Terminals
No. 3 — No. 5:
No. 4 — No. 6:
Is the measured value less than the speci-
fied value?
2 CHECK GROUND CIRCUIT OF ECM.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B134) No. 7 — Chassis ground:
(B134) No. 12 — Chassis ground:
(B134) No. 15 — Chassis ground:
(B134) No. 22 — Chassis ground:
(B136) No. 8 — Chassis ground:
(B136) No. 17 — Chassis ground:
(B136) No. 18 — Chassis ground:
(B137) No. 8 — Chassis ground:
(B137) No. 9 — Chassis ground:
(B84) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied value?
3 CHECK INPUT VOLTAGE OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B137) No. 10 (+) — Chassis ground (–):
Does the measured value exceed the specified
value?
4 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (–):
Does the measured value exceed the spec-
ified value?
5 CHECK HARNESS BETWEEN ECM AND
MAIN RELAY CONNECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between ECM and
chassis ground.
Connector & terminal
(B134) No. 2 — Chassis ground:
Does the measured value exceed the spec-
ified value?
Value
10 Ω
5 Ω
10 V
10 V
1 MΩ
EN(H4DOSTC)-57
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Replace the main
relay.
Go to step 3. Repair the open
circuit in harness
between ECM
connector and
engine grounding
terminal.
Go to step 4. Repair the open or
ground short cir-
cuit of power sup-
ply circuit.
Go to step 5. Repair the open or
ground short cir-
cuit of power sup-
ply circuit.
Go to step 6. Repair ground
short circuit in har-
ness between
ECM connector
and main relay
connector.
No