Inspection Procedure 7
CIRCUIT OPERATION- The fan control module is powered from fusible link number 5.
- 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 control module to drive the radiator fan motor and condenser fan motor.
TECHNICAL DESCRIPTION
The fan control module has variable control of the radiator fan motor and the condenser fan motor speeds using signals transmitted from the ECM [M/T] or PCM [A/T].
TROUBLESHOOTING HINTS
- Malfunction of fan control relay
- Malfunction of fan control module
- 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 Fan Control Relay.
If the fan control relay is faulty, replace it. Then go to Step 6.
If normal, go to Step 2.
STEP 2. Check The Harness Wire Between Fan Control Relay Connector A-13X And Fan Control Module Connector A-30.
If any harness wire between fan control relay connector A-1 3X and fan control module connector A-30 is damaged, repair or replace it. Then go to Step 6.
If harness wire is in good condition, go to Step 3.
STEP 3. Check The Circuit At ECM Connector C-51 [M/T] Or PCM Connector C-52 [A/T].
1. Connect ECM connector C-51 [M/T] or PCM connector C-52 [A/T].
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.
- Voltage should be 0 - 0.3 volt (When radiator fan is not operating)
- Voltage should be 0.7 volt or more (When radiator fan is operating)
If abnormal, go to Step 4.
If normal, go to Step 6.
STEP 4. Check The Harness Wire Between ECM Connector C-51 [M/T] Or PCM Connector C-52 [A/T] And Fan Control Module Connector A-30.
If any harness wires between ECM connector C-51 [M/T] or PCM connector C-52 [A/T] and fan control module connector A-30 are damaged, repair or replace them. Then go to Step 6.
If harness wires are in good condition, go to Step 5.
NOTE: If intermediate connector G07 is damaged, repair or replace it.
STEP 5. Check The Fan Control Module At ECM Connector C-51 [M/T] Or PCM Connector C-52 [A/T].
1. Connect ECM connector C-51 [M/T] or PCM connector C-52 [A/T].
2. Turn the ignition switch to "ON" position.
3. Pull out the terminal number 18 to disconnect it.
- The radiator fan motor and condenser fan motor operate.
4. Connect the terminal number 18 to the body ground.
- The radiator fan motor and condenser fan motor stop.
If abnormal, replace the radiator fan motor and fan control module assembly. Then go to Step 6.
If normal, replace the ECM [M/T] or PCM [A/T]. Then go to Step 6.
STEP 6. Check The Symptoms.
Confirm the radiator fan and condenser fan operate correctly.