Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 523

13B-42
INSPECTION PROCEDURE 26
Fuel pump system
The engine-ECU turns the fuel pump relay ON when the engine is cranking or running,
and this supplies power to drive the fuel pump.
Check the fuel pump operation.
(Refer to P.13B-69.)
OK
Check the fuel pump relay.
(Refer to P.13B-71.)
OK
Measure at the fuel pump relay connec-
tor B-27.
Connect the connector.
Voltage between 1 and earth
MUT-II Actuator test: Fuel pump
drive
OK: System voltage
OK
Check the harness wire between fuel
pump relay connector and fuel pump,
and repair if necessary.
MPI –
Troubleshooting
NG
Measure at the fuel pump connector
D-13.
Disconnect the connector, and
measure at the harness side.
Continuity between 4 and earth
OK: Continuity
OK
Check the following connectors:
B-18, B-27, D-13, D-15
OK
NG
Replace
Check trouble symptom.
NG
Check the harness wire between the
fuel pump relay and fuel pump connec-
tor.
OK
Replace the fuel pump.
NG
Measure at the fuel pump relay connec-
tor B-27.
Disconnect the connector, and
measure at the harness side.
Voltage between 4 and earth
(Ignition switch: ON)
OK: System voltage
Measure at the engine-ECU connector
B-28.
Disconnect the connector, and
measure at the harness side.
Voltage between 22 and earth
(Ignition switch: ON)
OK: System voltage
Check the following connector: B-28
Check trouble symptom.
Replace the engine-ECU.
Probable cause
Malfunction of the fuel pump relay
Malfunction of the fuel pump
Improper connector
short-circuited harness wire
Malfunction of the engine-ECU
NG
NG
NG
NG
OK
NG
OK
NG
OK
NG
contact, open circuit
Check the following connectors:
D-13, D-15
OK
NG
Repair
Check trouble symptom.
NG
Repair
Check the harness wire between the
fuel pump and earth, and repair if nec-
essary.
Repair
Check the following connectors:
B-18
OK NG
Repair
Check trouble symptom.
NG
Check the harness wire between the
fuel pump relay and ignition switch con-
nector.
OK NG
Repair
Check the ignition switch.
(Refer to GROUP 54 – Ignition Switch
and Immobilizer System.)
Check the following connector: B-27
OK NG
Repair
Repair
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the fuel pump relay,
and repair if necessary.
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