Cooling Fans - Evolution Mitsubishi Lancer Evolution VIII

DESCRIPTION & OPERATION

The fan control module is powered from fusible link No. 2. (Scheme 28) The ECM judges the required revolution speed of radiator fan motor and condenser fan motor using input signals transmitted from the A/C switch, automatic compressor controller, vehicle speed sensor and engine coolant temperature sensor. The ECM activates the fan control module to drive the radiator fan motor and condenser fan motor.

COMPONENT LOCATIONS

COMPONENT LOCATIONS

Scheme 28

TROUBLE SHOOTING

Note. To trouble shoot mechanical cooling system components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

COOLING FAN MOTOR

Remove the center under cover. Remove the cooling fan motor connector. Connect battery voltage to terminal No. 1 and ground terminal No. 2 and see if cooling fan operates. (Scheme 29) Also check that there are not abnormal sounds coming from the radiator fan motor. If radiator fan motor is defective, replace it. Install the center under cover.

Scheme 29

FAN CONTROL MODULE

1. Remove the center under cover.
2. Disconnect the fan control module connector. (Scheme 32)
3. Turn the ignition switch to the ON position. Check for battery voltage between terminals No. 1 and 3.
4. Turn the ignition switch to the LOCK position, and connect the fan control module connector.
5. Insert Probe (MB991222) at the back of the cooling fan motor connector. (Scheme 30)
6. Connect Probe (MB991222) to the circuit tester.
7. Measure voltage between the fan control module terminals. Voltage should be 1V or less.
8. Turn the A/C switch to the ON position.
9. Measure the voltage between the fan control module (side connector) terminals while the fan is running. The voltage should repeat values 5.6-10.8V and battery voltage.
10. If the voltage does not repeatedly change as indicated, replace the fan control module.
11. Install the center under cover.

Scheme 30

Scheme 31

SYMPTOM TESTS

RADIATOR FAN & CONDENSER FAN SYMPTOMS

Technical Description

1. The cause could be a malfunction of the fan control module power supply or ground circuit.
2. The cause could also be a malfunction of the fan control module of the ECM.

Troubleshooting Hints

1. Malfunction of fusible link.
2. Malfunction of fan control relay.
3. Malfunction of cooling fan motor.
4. Malfunction of fan control module.
5. Malfunction of ECM.
6. Damaged wiring harness or connector.

Diagnosis

1. Disconnect fan control module connector A-17. (Scheme 32) Measure for voltage between terminal No. 3 (harness side of the connector) and ground when ignition switch is turned to the ON position. If battery voltage is not achieved, go to next step. If battery voltage is achieved, go to step 8.
2. Check fan control relay. See «FAN CONTROL RELAY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-fan/#cooling-fans-evolution) under COMPONENTS TESTS. If fan control relay is okay, go to next step. If fan control relay is not okay, replace it and retest.
3. Check for harness damage in Black/White wire between fusible link No. 2 and terminal No. 4 of fan control relay connector A-09X. (Scheme 33) If wire is okay, go to next step. If wire is damaged, repair or replace as necessary and retest.
4. Check for harness damage in Blue wire between terminal No. 2 of fan control relay connector A-09X and terminal No. 3 of fan control module connector A-17. (Scheme 32)and (Scheme 33). If wire is okay, go to next step. If wire is damaged, repair or replace as necessary and retest.
5. Check for harness in damage in Red/Yellow wire between MFI relay and terminal No. 1 of fan control relay connector A-09X. (Scheme 33) If wire is okay go to next step. If wire is damaged, repair or replace as necessary and retest.
6. Check for harness damage between terminal No. 3 of fan control relay connector A-09X and ground. (Scheme 33) If wire is damaged, repair it and retest.
7. Check the cooling fan motor. See «COOLING FAN MOTOR»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-fan/#cooling-fans-evolution__cooling-fan-motor) under COMPONENT TESTS. If cooling fan motor is okay, go to next step. If cooling fan motor is damaged, replace it and retest.
8. Disconnect fan control module connector A-17. (Scheme 32) Measure resistance between terminal No. 1 (harness side of connector) and ground. If the resistance is more than 2 ohms go to next step. If resistance is less than 2 ohms, go to step 10.
9. Check the harness wires between fan control module connector A-17 and ground. If harness wires are okay go to next step. If harness wires are damaged, repair as necessary and retest.
10. Start the engine and allow it to idle. Turn the A/C switch to the ON position. Measure the output circuit voltage between terminal No. 21 of connector C-121 and ground by backprobing. (Scheme 36) If the voltage when the radiator fan is operating is less than 0.7V, go to next step. If the voltage when the radiator fan is operating is more than 0.7V, go to step 12.
11. Check the harness wire between terminal No. 21 of connector C-121 and terminal No. 2 of fan control module connector A-17. (Scheme 32)and (Scheme 36). If wiring is damaged, repair or replace as necessary and retest. If wiring is okay, go to next step.
12. Disconnect ECM connector. Turn the ignition switch to the ON position. If the radiator fan motor and condenser fan motor operate, replace the ECM and retest. If the radiator fan motor and condenser fan motor do not operate, replace the fan control module and retest.

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

TEST B: COOLING FAN DOES NOT CHANGE SPEED OR STOP

Note. If the engine coolant temperature reaches 230°F (110°C) or higher, the radiator fan control runs the radiator fan for up to 5 minutes even after the ignition switch is turned to the LOCK position. The fan stops its rotation when the engine coolant temperature decreases to 230°F (110°C) or lower.

The fan control module has variable control of the radiator fan motor and the condenser fan motor speeds using signals transmitted from the ECM.

1. Malfunction of fan control relay.
2. Malfunction of fan control module.
3. Malfunction of ECM.

1. Check the fan control relay. See «FAN CONTROL RELAY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-fan/#cooling-fans-evolution) under COMPONENT TESTS. If fan control relay is okay, go to next step. If fan control module is damaged, repair or replace as necessary and retest.
2. Check the harness wire between terminal No. 2 of fan control relay connector A-09X and terminal No. 3 of fan control module connector A-17. (Scheme 32)and (Scheme 33). If wiring is damaged, repair or replace as necessary and retest. If wiring is okay, go to next step.
3. Start the engine and allow it to idle. Measure the output circuit voltage between terminal No. 21 of connector C-121 and ground by backprobing. (Scheme 36) If the voltage when the radiator fan is not operating is more than 0.3V, go to next step. If the voltage when the radiator fan is not operating is less than 0.3V, go to step 6.
4. Start engine and allow it to idle. Turn the A/C switch to the ON position. Measure the output circuit voltage at terminal No. 21 of ECM connector C-121. (Scheme 36) If output voltage is less than 0.7V, go to next step. If output voltage is 0.7V or more, go to step 6.
5. Check the harness wire between terminal No. 21 of connector C-121 and terminal No. 2 of fan control module connector A-17. (Scheme 32)and (Scheme 36). If wiring is damaged repair or replace as necessary and retest. If wiring is okay, go to next step.
6. Pull out terminal No. 21 of ECM connector C-121. (Scheme 36) Turn the ignition switch to the ON position. If cooling fan motor does not operate, go to next step. If cooling fan motor operates, replace ECM and retest.
7. Disconnect ECM connector. Pull out pin No. 21 of connector C-121 and connect it to a body ground. (Scheme 36) Reconnect ECM connector with pin No. 21 still removed. Turn the ignition switch to ON position. If the cooling fan motor fan motor stops operating, replace the ECM or PCM and retest. If the cooling fan motor does not stop operating, replace the fan control module and retest.

Removal & Installation

1. Remove under cover.
2. Drain engine coolant.
3. Remove battery and battery tray.
4. Remove air cleaner assembly.
5. Remove air hose "E", air pipe "C", and air hose "D". See appropriate article in ENGINES.
6. Remove air pipe "B" mounting bolt. (Scheme 38)
7. Disconnect fan control module connector. (Scheme 38)
8. Disconnect the cooling fan motor connector.
9. Remove fan control module.
10. Remove cooling fan motor, cooling fan, and shroud assembly.
11. Remove cooling fan.
12. Remove cooling fan motor.
13. Remove cooling fan shroud.
14. To install, reverse removal procedures.

Scheme 37

Scheme 38

WIRING DIAGRAMS

See COOLING FAN in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

See also:
• A
• B
• COOLING FAN MOTOR