The engine cooling fan system consists of one cooling fan and one relay. The relay is powered by the battery positive voltage circuit and controlled by a switched ground from the engine control module (ECM).

During operation, the ECM supplies the ground path for the cooling fan relay through the cooling fan relay control circuit. This energizes the cooling fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cooling fan fuse through the cooling fan motor supply voltage circuit to the cooling fan. The cooling fan motor is grounded through its own ground circuit.

The ECM commands the fan on under the following conditions:

• Engine coolant temperature exceeds approximately 106°C (223°F).

• A/C refrigerant pressure exceeds 1302 kPa (189 psi).

• A/C is requested and vehicle speed is below 100 km/h (62 mph) with A/C pressure above 1413 kPa (205 psi).

• AF23-5 Transmission fluid temperature exceeds 130°C (266°F).

• VT25-E Transmission fluid temperature exceeds 140°C (284°F).

• When the engine coolant temperature exceeds 125°C (257°F) at key off, the fan will run for up to 108 seconds.

The ECM commands the fan off under the following conditions:

• Engine coolant temperature drops below approximately 125°C (257°F).

• Throttle position is greater than 95 percent.

• Vehicle speed exceeds 113 km/h (70 mph)

 

Good to know that temps while at idle can run 205 or higher if sitting at a stop light for a bit?? No?



I have no idea why this is all of a sudden an issue for me(thinking my temps are high)



Goose