Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 113

13D-48
INSPECTION PROCEDURE 25
Fans (radiator fan, A/C condenser fan) are inoperative
The engine-ECU <M/T> or engine-A/T-ECU <A/T> outputs a duty signal to the
fan controller depending on the engine coolant temperature, vehicle speed, and
air conditioner switch condition.
Based on this signal, the fan controller controls the radiator fan and condenser
fan speeds (The more the average voltage at the terminal approaches 5 V, the
higher the fan speed become.)
Measure at the engine-ECU connector B-54 <M/T> or the
engine-A/T-ECU connector B-113 <A/T>.
D Disconnect the connector, and measure at the harness
side.
D Voltage between 21 <M/T>, 18 <A/T> and earth (Ignition
switch: ON)
OK: 4.8 - 5.2 V (Fan rotates at high speed.)
D Connect a jumper cable between 21 and earth (Ignition
switch: ON)
OK: Fan stops
OK
NG
Check the following
connector:
C-34
OK
Check trouble symptom.
NG
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 <M/T> or engine-A/T-ECU <A/T>
MPI -
Repair
OK
OK
Troubleshooting
Probable cause
D Malfunction of the fan motor relay
D Malfunction of the fan motor
D Malfunction of the fan controller
D Improper connector contact, open circuit or
short-circuited harness wire
D Malfunction of the engine-ECU <M/T> or
engine-A/T-ECU <A/T>
NG
Check the following
connector: A-28, A-37
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU
<M/T> or
A/T-ECU <A/T> and the
fan controller connector.
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.13D-16, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
21.)
NG
Replace
NG
Repair
NG
Repair
engine-