Radiator Cooling Fan Control Module: Testing and Inspection
FAN CONTROL MODULE CHECKRequired Special Tool:
^ MB991222: Probe
1. Remove the center under cover.
2. Disconnect the fan control module connector.
3. Turn the ignition switch to the "ON" position, and measure the voltage between the harness-side connector terminals.
Standard value: Battery positive voltage
4. Turn the ignition switch to the "LOCK" (OFF) position, and connect the fan control module connector.
5. Insert special tool MB991222 at the back of the cooling fan motor connector.
6. Connect special tool MB991222 to the circuit tester.
7. Ensure that the A/C switch is off, and start the engine and run it at idle.
8. Measure the voltage between the cooling fan motor connector terminals.
Standard value: 1V or less
9. Turn the A/C switch to the "ON" position.
WARNING: Stay clear of the fan when the fan starts running.
10. Measure the voltage between the cooling fan motor connector terminals while the fan is running. The voltage should repeat the values 1) and 2).
Standard value:
1. 8.2 ± 2.6 V
2. Battery positive voltage ± 2.6 V
11. If the voltage does not repeatedly change as indicated, replace the fan control module.
12. Install the center under cover.