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Home >> Mitsubishi >> 2004 >> Lancer L4-2.0L SOHC >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Cooling System >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Inspection Procedure 3

Inspection Procedure 3

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INSPECTION PROCEDURE 3: Radiator Fan and Condenser Fan do not Operate

CIRCUIT OPERATION
^ The fan controller is powered from fusible link number 2.
^ The ECM [M/T] or PCM [A/T] 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 ECM [M/T] or PCM [A/T] 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 ECM [M/T] or PCM [A/T].

TROUBLESHOOTING HINTS
^ Malfunction of fusible link
^ Malfunction of fan control relay
^ Malfunction of MFI relay
^ Malfunction of radiator fan motor
^ Malfunction of condenser fan motor
^ Malfunction of fan controller
^ Malfunction of ECM [M/T] or PCM [A/T]
^ Damaged wiring harness or connector

DIAGNOSIS

Required Special Tool:
^ MB991223: Harness Set

STEP 1. Check the circuit at fan controller connector A-17 (terminal 3).








1) Disconnect fan controller connector A-17, and measure at the harness side connector.
2) Measure the voltage between terminal number 3 and ground.
^ When the ignition switch is turned to the "ON" position, voltage should measure battery positive voltage.
Q: Is there voltage battery positive voltage when the ignition switch is turned to the "ON" position?
YES: Go to Step 8.
NO: Go to Step 2.

STEP 2. Check the fan control relay.
Q: Is the fan control relay in good condition?
YES: Go to Step 3.
NO: Replace it, then go to Step 1.

STEP 3. Check the MFI relay.
Q: Is the MFI relay in good condition?
YES: Go to Step 4.
NO: Replace it, then go to Step 1.

STEP 4. Check for harness damage between fusible link number 2 and fan control relay connector A-09X (terminal 4).





Q: Are the harness wires between fusible link number 2 and fan control relay connector A-10X damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 5.

STEP 5. Check for harness damage between fan control relay connector A-09X (terminal 2) and fan controller connector A-17 (terminal 3).








Q: Are the harness wires between fan control relay connector A-09X (terminal 2) and fan controller connector A-17 (terminal 3) damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 6.

STEP 6. Check for harness damage between MFI relay connector B-12X and fan control relay connector A-09X.








NOTE: After inspecting intermediate connector A-13 terminal 8 and joint connector C-105 terminal 33, 28 inspect the wires. If intermediate connector A-13 and joint connector C-105 are damaged, repair or replace them.





Q: Are the harness wires between MFI relay connector B12X (terminal 4) and fan control relay connector A-09X (terminal 1) damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 7.

STEP 7. Check for harness damage between fan control relay connector A-09X (terminal 3) and ground.





Q: Are the harness wires between fan control relay connector A-09X (terminal 3) and ground damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 8.

STEP 8. Check the circuit at fan controller connector A-17 (terminal 1).








1) Disconnect fan controller connector A-17, and measure at the harness side connector.
2) Measure the resistance between terminal number 1 and ground.
Q: Is the resistance less than 2 ohms?
YES: Go to Step 10.
NO: Go to Step 9.

STEP 9. Check the harness wire between fan controller connector A-17 and ground.





Q: Are the harness wires between fan controller connector A-17 and ground damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 10.

STEP 10. Measure the output circuit voltage at ECM connector C-121 [M/T] (terminal 21) or PCM connector C-120 [A/T] (terminal 18) by backprobing.








1) Do not disconnect ECM connector C-121 [M/T] or PCM connector C-120 [A/T].
2) Start the engine and allow it to idle.
3) Measure the voltage between terminal number 21 [M/T] or 18 [A/T] and ground by back probing.
Q: Is the voltage 0.7 volt or more when the radiator fan is operating?
YES: Go to Step 12.
NO: Go to Step 11.

STEP 11. Check the harness wire between ECM connector C-121 [M/T]or PCM connector C-120 [A/T] and fan controller connector A-30.





NOTE: If intermediate connector A-13 terminal 1 is damaged, repair or replace it.








Q: Are the harness wires between ECM connector C-121 [M/T] (terminal 21) or PCM connector C-120 [A/T] (terminal 18) and fan controller connector A-17 (terminal 2) damaged?
YES: Repair or replace them, then go to Step 13.
NO: Go to Step 12.

STEP 12. Check the fan controller at ECM connector C-121 [M/T] or PCM connector C-120 [A/T].





1) Disconnect ECM connector C-121 [M/T] or PCM connector C-120 [A/T].
2) Turn the ignition switch to the "ON" position.
Q: Do the radiator fan motor and condenser fan motor operate?
YES: Replace the PCM. Then go to Step 13.
NO: Replace the fan controller. Then go to Step 13.

STEP 13. Check the symptoms.
Q: Do the radiator fan and condenser fan operate correctly?
YES: The procedure is complete.
NO: Return to Step 1.

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