ELECTRICAL FAN CONTROL OPERATION [L3 R.H.D.]

BUE014000000N45


1	Control duty ratio
2	Coolant temperature
3	A/C switch ON

• When the engine coolant temperature is less than set value Tw1, the control duty ratio from by the PCM is 0%. Accordingly, the fan control module output duty ratio is also 0% and the cooling fan is stopped.

• When the engine coolant temperature passes Tw1, the control duty ratio from the PCM varies between LO-HI in relation to engine coolant temperature. and the cooling fan is driven accordingly.

• When the engine coolant temperature reaches set temperature Tw2, the duty ratio remains at HI until the engine coolant temperature is at set temperature Tw3.

• When the engine coolant temperature goes above Tw3, the duty ratio is MAX and the cooling fan operates at maximum speed.

A/C On And Refrigerant Pressure Control Signals

• When the A/C switch is ON and the refrigerant pressure rises above a set value, the control duty ratio from the PCM is approx. 100%, regardless of engine coolant temperature, and the cooling fan operates at maximum speed.

Fail Safe

• If the ECT sensor malfunctions, the PCM control duty ratio is fixed at MAX.

Battery Voltage Correction

• To prevent variation of cooling fan speed due to battery voltage fluctuation, the PCM adjusts the duty ratio to maintain the cooling fan at a constant speed and stabilize cooling efficiency.