Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 522

INSPECTION PROCEDURE 24
Check the engine-ECU power supply and earth circuit.
Measure the engine-ECU connectors, B-28, B-29, B-31.
Disconnect the connector and measure at the harness side
1. Voltage between 82 and earth (Ignition switch: ON)
OK: System voltage
2. Voltage between 38 and earth
OK: System voltage
3. Voltage between 12, 25 and earth (Ignition switch: ON)
OK: System voltage (when the terminal 38 is earthed)
4. Continuity between 13, 26 and earth
OK: Continuity
5. Voltage between 80 and earth
OK: System voltage
OK
NG
Check the following
connectors:
B-28, B-29, B-31
OK
Check trouble symptom.
NG
Replace the engine-ECU.
Check the following connectors:
B-18, B-45
OK
Check trouble symptom
NG
Check the harness wire between engine-ECU and battery, and
repair if necessary.
INSPECTION PROCEDURE 25
Power supply system and ignition switch-IG system
When an ignition switch ON signal is input to the engine-ECU, the engine-ECU
turns the control relay ON. This causes battery voltage to be supplied to the
engine-ECU, injectors and air flow sensor.
Check the control relay. (Refer to P.13B-71.)
Measure at the control relay connector B-26.
Disconnect the connector, and measure at the harness side.
Voltage between 3, 4 and earth
OK: System voltage
Check the engine-ECU power supply and earth circuit.
(Refer to P.13B-41, INSPECTION PROCEDURE 24.)
MPI –
Repair
NG
Repair
OK
OK
Troubleshooting
1. NG
Check the following
connector: B-18
OK
2, 3. NG
Check trouble symptom.
OK
4. NG
Check the harness wire
between engine-ECU and
5. NG
ignition switch connector.
OK
Check the ignition switch.
(Refer to GROUP 54 – Ignition Switch and Immobilizer System.)
Check the following
connector: B-26
OK
Check trouble symptoms.
NG
Check the harness wire between engine-ECU and control relay
connector, and repair if necessary.
Check the harness wire between engine-ECU and earth, and
repair if necessary.
Probable cause
Malfunction of the ignition switch
Malfunction of the control relay
Improper
short-circuited harness wire
Disconnected engine-ECU earth wire
Malfunction of the engine-ECU
NG
Replace
NG
Check the following
connector: A-23
OK
Check trouble symptom.
NG
Check the harness wire between battery and control relay connec-
tor, and repair if necessary.
13B-41
NG
Repair
NG
Repair
NG
Repair
connector contact, open circuit
NG
Repair
or