Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 421

13A-62
INSPECTION PROCEDURE 21
Fans (radiator fan, A/C condenser fan) are inoperative.
The engine-ECU sends a duty signal to the fan controller according to engine coolant
temperature, vehicle speed, or A/C switch load.
The fan controller controls radiator fan and condenser fan speeds, based on this
signal. (The closer the terminal voltage comes to 5 V, the higher the fan speed
becomes.)
Measure at engine-ECU connector A-28.
Disconnect the connector, measure at the harness side.
Voltage between terminal 21 and earth
(Ignition switch: ON)
OK: 4.8 – 5.2 V (The fan runs at high speed.)
Earth terminal 21.
(Ignition switch: ON)
OK: The fan stops.
Check the following connector: A-28
OK
Check trouble symptom.
MUT-II Data list
21 Engine coolant temperature sensor
OK: After the engine has been warmed up, the engine coolant
temperature during idling is identical to the MUT-II reading.
Check the thermostat.
Replace the engine-ECU.
GDI –
OK
NG
Repair
NG
OK
OK
Troubleshooting
Probable cause
Malfunction of the fan motor relay
Malfunction of the fan motor
Malfunction of the fan controller
Open or short circuit, or poor connector contact
Malfunction of the engine-ECU
NG
Check the following connector: A-23, A-32
OK
Check trouble symptom.
NG
Check the harness wire between the engine-ECU and fan controller.
OK
Check the radiator fan and condenser fan circuit. (Refer to GROUP
14 – Troubleshooting.)
NG
Check the engine coolant temperature sensor system. (Refer to
P.13A-18, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
21.)
NG
Replace
NG
Repair
NG
Repair