Cooling Fan Always On

Cooling Fan Always On

Circuit/System Description

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, which is relay 1, 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.


Circuit/System Verification

1. If DTC P0480 is set, perform that diagnostic first.
2. Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
3. Ignition ON, observe that the fan is not activated.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the relay.
2. Ignition ON, observe that the fan is not activated.
* If the fan is not activated, replace the relay.
* If the fan is activated, test the fan voltage supply circuit for a short to voltage.

Repair Instructions

* Cooling Fan and Shroud Replacement
* Fan Shroud Replacement
* Engine Control Module Replacement for the 2.2L engine
* Engine Control Module Replacement for the 2.4L engine

Repair Verification

1. Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
2. Ignition ON, observe that the fan is not activated.