MPI <4G1> -
Troubleshooting
13A-58
INSPECTION PROCEDURE 23
Fans (radiator fan, A/C condenser fan) are inoperative.
Probable cause
The fan motor relay is controlled by the power transistor inside the engine-ECU turning
ON and OFF.
D
Malfunction of the fan motor relay
D
Malfunction of the fan motor
D
Malfunction of the thermostat
D
Improper connector contact, open circuit or
short-circuited harness wire
D
Malfunction of the engine-ECU
OK
Check the trouble symptoms.
OK
Check the following connector:
B-37
NG
Repair
Measure at the engine-ECU connector B-37.
D
Disconnect the connector, and measure at the harness side.
D
Check the condition of the fans (radiator fan and A/C condenser
fan). (Ignition switch: ON)
OK:
Fans are stopped
D
Voltage between 20 and earth, 21 and earth
(Ignition switch: ON)
OK:
System voltage
D
Connect a jumper wire between 20 and earth
(Ignition switch: ON)
OK:
Radiator fan and condenser fan run at high speed.
D
Connect a jumper wire between 21 and earth
(Ignition switch: ON)
OK:
Radiator fan and condenser fan run at low speed.
NG
D
Check the radiator fan circuit. (Refer to ELECTRICAL WIRING.)
D
Check the A/C condenser fan circuit.
(Refer to ELECTRICAL WIRING.)
NG
MUT-
II
Data list
21 Engine coolant temperature sensor
OK:
After the engine has warmed up, the engine coolant tempera-
ture durning idling is identical to the MUT-
II
reading.
NG
Check the engine coolant temperature sensor system.
(Refer to P.13A-13, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE P0115.)
OK
Replace the engine-ECU.
OK
Check the thermostat.
NG
Replace