Electric Cooling Fan System

Dual electric cooling fans aid air flow through the radiator. The fans are driven by electric motors that attach to the fan shroud.

The fan motors are activated by the cooling fan relays.

Caution: An electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

If diagnosis is to be performed on a coolant fan electrical malfunction, refer to Powertrain Management.

Circuit Description
The electric cooling fan(s) are controlled by the Body Control Module (BCM) which enables the fans through the PCM. The PCM enables the ground path for the three cooling fan relays. The relay(s) are used to control the high current flow to power the cooling fan motors. When minimum cooling is required, the BCM will command the PCM to energize cooling fan relay #1 and since both fans are connected in series through the Mode Control relay, both fans will operate at low speed. When maximum cooling is required, the BCM will command the PCM to energize all three cooling fan relays. Power is supplied to the left fan through cooling fan relay #1 and is grounded through the Mode Control relay. The right fan is powered directly through cooling fan relay #2 causing both fans to operate at high speed.

For diagnistic information see Electric Cooling Fan Diagnosis under Computers and Control Systems, Procedures . Component Tests and General Diagnostics