Mitsubishi Galant. Manual — part 332

ENGINE COOLING DIAGNOSIS

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ENGINE COOLING

14-6

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 cause could be a malfunction of the fan
controller power supply or ground circuit.

•

The cause could also be a malfunction of the fan
controller or the PCM.

TROUBLESHOOTING HINTS

•

Malfunction of fusible link

•

Malfunction of fan control relay

•

Malfunction of fan controller

•

Malfunction of PCM

•

Damaged wiring harness or connector

DIAGNOSIS

Required Special Tool:

•

MB991223: Harness Set

STEP 1. Check the circuit at fan controller connector A-30.
(1) Disconnect fan controller connector A-30, and measure at

the harness side connector.

(2) Measure the voltage between terminal number 3 and

ground.

•

When the ignition switch is turned to "ON" position,
voltage should be battery positive voltage.

Q: Is the voltage battery positive voltage when the ignition

switch is turned to "ON" position?
YES : Go to Step 7.
NO : Go to Step 2.

STEP 2. Check the fan control relay.
Refer to

P.14-15

.

Q: Is the fan control relay in good condition?

YES : Go to Step 3.
NO : Replace it, then go to Step 10.

AC004036AB

CONNECTOR: C-04

AC004037AB

CONNECTOR: C-39

PCM

AC000246

CONNECTOR A-30

AB

ENGINE COOLING DIAGNOSIS

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ENGINE COOLING

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STEP 3. Check for continuity between fusible link number
5 and fan control relay connector A-13X.
Q: Are the harness wires between fusible link number 5

and fan control relay connector A-13X damaged?
YES : Repair or replace them, then go to Step 12.
NO : Go to Step 4.

STEP 4. Check for continuity between fan control relay
connector A-13X and fan controller connector A-30.
Q: Are the harness wires between fan control relay

connector A-13X and fan controller connector A-30
damaged?
YES : Repair or replace them, then go to Step 12
NO : Go to Step 5.

STEP 5. Check for continuity between MFI relay connector
A-21X and fan control relay connector A-13X.
Q: Are the harness wires between MFI relay connector A-

21X and fan control relay connector A-13X damaged?
YES : Repair or replace them, then go to Step 12.
NO : Go to Step 6.

AC000247AC

BATTERY

FUSIBLE LINK (4) AND
CONNECTOR: A-13X

A-13X

FUSIBLE
LINK (4)

AC000248AB

CONNECTOR: A-13X

BATTERY

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

AC000250

BATTERY

CONNECTORS: A-13X, A-21X

A-13X

A-21X

AB

ENGINE COOLING DIAGNOSIS

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ENGINE COOLING

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STEP 6. Check for continuity between fan control relay
connector A-13X and ground.
Q: Are the harness wires between fan control relay

connector A-13X and ground damaged?
YES : Repair or replace them, then go to Step 12.
NO : There is no action to be taken.

STEP 7. Check the circuit at fan controller connector A-30.
(1) Disconnect fan controller connector A-30, and measure at

the harness side connector.

(2) Measure the resistance between terminal number 1 and

ground.

Q: Is the resistance less than 2 ohm?

YES : Go to Step 9.
NO : Go to Step 8.

STEP 8. Check the harness wire between fan controller
connector A-30 and ground.
Q: Are the harness wires between fan controller connector

A-30 and ground damaged?
YES : Repair or replace them, then go to Step 12.
NO : There is no action to be taken.

STEP 9. Check the circuit at PCM connector C-39.
(1) Connect PCM connector C-39.
(2) Start the engine and allow it to idle.
(3) Measure the voltage between terminal number 18 and

ground.

Q: Is the voltage 0.7 volt or more when the radiator fan is

operating?
YES : Go to Step 11.
NO : Go to Step 10.

AC000248AB

CONNECTOR: A-13X

BATTERY

AC000252 AB

CONNECTOR: A-30

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

AC004039 AB

CONNECTOR
C-39

ENGINE COOLING DIAGNOSIS

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ENGINE COOLING

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STEP 10. 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 12.
NO : Go to Step 11.

STEP 11. Check the fan controller at PCM connector C-39.
(1) Disconnect PCM connector C-39.
(2) Pull out pin 18 to disconnect it.
(3) Reconnect PCM connector C-39 with pin 18 still removed.
(4) Turn the ignition switch to "ON" position.

Q: Do the radiator fan motor and condenser fan motor

operate?
YES : Replace the PCM. Then go to Step 12.
NO : Replace the radiator fan motor and fan controller

assembly.Then go to Step 12 .

AC004036AB

CONNECTOR: C-04

AC004037AB

CONNECTOR: C-39

PCM

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

AC004040AB

CONNECTOR C-39