Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 575

14-6
Inspection Procedure 2
Radiator fan and condenser fan do not change speed or
stop. <Vehicles with A/C>
Radiator fan does not change speed or stop.
<Vehicles without A/C>
The fan controller carries out step-free control of the radiator fan motor and the
condenser fan motor speeds using signals transmitted from the engine-ECU.
<Vehicles with A/C>
Fan control relay check (Refer to P.14-10.)
Check the harness wire between fan control relay and engine
control relay.
Check the harness wire between fan control relay and body
earth.
Check the harness wire between fan control relay and fan
controller.
Measure at the engine-ECU connectors A-28.
Connect the connector.
Voltage between 21 and body earth
(Engine: idling, engine coolant temperature: 80_C or less)
OK: 0 – 0.3 V (Engine: idling, A/C switch: ON)
OK: 0.7 V or more (When A/C compressor is operating)
Fan controller check (Refer to P.14-10.)
Measure at the engine-ECU connectors A-28.
Connect the connector.
Pull out the terminal No.21 to disconnect it (Ignition switch: ON)
OK: The radiator fan motor and condenser fan motor operate.
Connect the terminal No.21 to the body earth (Ignition switch: ON)
OK: The radiator fan motor and condenser fan motor stop.
Engine-ECU terminal voltage check (Refer to GROUP 13A – Trou-
bleshooting.)
ENGINE COOLING –
OK
OK
OK
OK
YES
Troubleshooting
Probable cause
Malfunction of fan control relay
Malfunction of fan controller
Malfunction of engine-ECU
Malfunction of wiring harness or connector
NG
Replace
NG
Repair
NG
Check the harness wire between fan controller and engine-ECU.
Engine-ECU terminal voltage check (Refer to GROUP 13A – Trou-
bleshooting.)
Check the automatic compressor-ECU, and repair if necessary.
(Refer to GROUP 55 – Troubleshooting.)
NG
Replace the radiator fan motor and fan controller assembly.
Replace the radiator fan motor and fan controller assembly.
NG
Repair
OK
NG
Replace
OK
NO