Mitsubishi Galant. Manual — part 333

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-10

STEP 12. Check the symptoms.

Q: Do the radiator fan and condenser fan operate

correctly?
YES : This diagnosis is complete.
NO : Return to Step 1.

INSPECTION PROCEDURE 4: Radiator Fan and Condenser Fan do not Change Speed or Stop

NOTE: If the engine coolant temperature reaches 110

°

C(230

°

F) or higher, the radiator fan control rotates the

radiator fan for up to 5 minutes even after the ignition switch is turned to the "LOCK (OFF)" position [the fan
stops its rotation when the engine coolant temperature decreases to 110

°

C(230

°

F) or lower

.

]

Radiator Fan and Condenser Fan Drive Circuit
Refer to

P.14-5

.

CIRCUIT OPERATION

•

The fan controller is powered from fusible link
number 5.

•

The PCM judges the required revolution speed of
radiator fan motor and condenser fan motor using
the input signals transmitted from A/C switch,
automatic compressor controller, vehicle speed
sensor and engine coolant temperature sensor.
The PCM activates the fan controller to drive the
radiator fan motor and condenser fan motor.

TECHNICAL DESCRIPTION
The fan controller has variable control of the radiator
fan motor and the condenser fan motor speeds using
signals transmitted from the PCM.

TROUBLESHOOTING HINTS

•

Malfunction of fan control relay

•

Malfunction of fan controller

•

Malfunction of PCM

DIAGNOSIS

Required Special Tool:

•

MB991223: Harness Set

STEP 1. Check the fan control relay.
Refer to

P.14-15

.

Q: Is the fan control relay in good condition?

YES : Go to Step 2.
NO : Replace the part, then go to Step 6.

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-11

STEP 2. Check the harness wire between fan control relay
connector A-13X and fan controller connector A-30.
Q: Are the harness wire between fan control relay

connector A-13X and fan controller connector A-30
damaged?
YES : Repair or replace the part, then go to Step 6.
NO : Go to Step 3.

STEP 3. Check the circuit at PCM connector C-39.
(1) Connect PCM connector C-39.
(2) Start the engine and run it at idle. [Engine coolant

temperature: 80

°

C (176

°

F) or less]

(3) Measure the voltage between terminal number 18 and

ground.

Q: Is the voltage 0

−−−−

0.3 volt when radiator fan is not

operating?
YES : Go to Step 6.
NO : Go to Step 4.

AC000248AB

CONNECTOR: A-13X

BATTERY

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

AC004040AB

CONNECTOR C-39

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-12

STEP 4. Check the harness wire between PCM connector
C-39 and fan controller connector A-30.

NOTE: If intermediate connector C-04 is damaged, repair or
replace it. Refer to GROUP 00E, Harness Connector
Inspection

P.00E-2

.

Q: Are the harness wires between PCM connector C-39 and

fan controller connector A-30 damaged?
YES : Repair or replace them, then go to Step 6.
NO : Go to Step 5.

STEP 5. Check the fan controller at PCM connector C-39.
(1) Connect PCM connector C-39.
(2) Turn the ignition switch to " ON" position.
(3) Pull out the terminal number 18 and connect it to the body

ground.

Q: Do the radiator fan motor and condenser fan motor

stop?
YES : Replace the PCM. Then go to Step 6.
NO : Replace the radiator fan motor and fan controller

assembly. Then go to Step 6 .

STEP 6. Check the symptoms.

Q: Do the radiator fan and condenser fan operate

correctly?
YES : This diagnosis is complete.
NO : Return to Step 1.

INSPECTION PROCEDURE 5: Radiator Fan does not Operate

TECHNICAL DESCRIPTION
The cause could be a malfunction of the radiator fan
motor or an open circuit between the fan controller
and the radiator fan motor.

TROUBLESHOOTING HINTS

•

Malfunction of radiator fan motor

•

Malfunction of fan controller

DIAGNOSIS
Replace the radiator fan motor and fan controller assembly.

Q: Does the radiator fan operate correctly?

YES : There is no action to be taken?
NO : Repair the wiring harness between the fan controller

and the radiator fan motor.

AC004037AB

CONNECTOR: C-39

PCM

AC004040AB

CONNECTOR C-39

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-13

INSPECTION PROCEDURE 6: Condenser Fan does not Operate

Radiator Fan and Condenser Fan Drive Circuit
Refer to

P.14-5

.

CIRCUIT OPERATION

•

The fan control module is powered from fusible
link number 4.

•

The PCM judges the required revolution speed of
radiator fan motor and condenser fan motor using
the input signals transmitted from A/C switch,
automatic compressor controller, vehicle speed
sensor and engine coolant temperature sensor.
The PCM activates the fan controller to drive the
radiator fan motor and condenser fan motor.

TECHNICAL DESCRIPTION
The cause could be a malfunction of the condenser
fan motor or of the fan controller.

TROUBLESHOOTING HINTS

•

Malfunction of condenser fan motor

•

Malfunction of fan controller

DIAGNOSIS

STEP 1. Check the condenser fan motor.
Refer to GROUP 55, Condenser and Condenser Fan
Motor

P.55-41

.

Q: Is the condenser fan in good condition?

YES : Replace the radiator fan motor and fan controller

assembly. Then go to Step 3 .

NO : Go to Step 2.

STEP 2. Check the fan controller.
Refer to

P.14-15

.

Q: Is the fan controller in good condition?

YES : Go to Step 3.
NO : Replace the fan controller, then go to Step 3.

STEP 3. Check the symptoms.

Q: Does the condenser fan operate correctly?

YES : This diagnosis is complete.
NO : Return to Step1.