Radiator Cooling Fan Control Module: Testing and Inspection

Cooling fan controller
Engine ECM controls the rate of cooling fan with engine coolant temperature and vehicle speed. The cooling fan controller receives signal from the ECM to control the rate of cooling fan.




ECM output
DUTY = T/256 micro sx 100%
The control to cooling fan is performed in ECM output + duty.




Cooling fan logic
1. The duty at A/C OFF

The Duty Of A/C On: