Cooling Fan Inoperative

Cooling Fan Inoperative (LHU)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The engine cooling fan system is composed of one electric cooling fan and a cooling fan control module. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module varies the voltage drop across the cooling fan motor in relation to the pulse width modulated signal, which enables cooling fan operation at variable speeds. The cooling fan control module is thermally protected to prevent module damage in the case of a short circuit condition in the cooling fan motor.

Reference Information

Schematic Reference

Engine Heating/Cooling Schematics [1][2]Cooling System

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

Description and Operation

Cooling Fan Description and Operation (LEA) Cooling Fan Description and OperationCooling Fan Description and Operation (LHU) Cooling Fan Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify that DTC P0480, P0691, or P0692, is not set.

• If a DTC is set
Refer to DTC P0480, P0691, or P0692 (LHU) P0480.

• If no DTC is set.

Note: A slight delay may occur before the cooling fan activates.

3. Verify the G10 Cooling Fan Motor activates and increases in speed with each command using a scan tool.

• The cooling fan does not activate or increase in speed
Refer to Circuit/System Testing

• The cooling fan activates and increases in speed

4. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the G10 Cooling Fan Motor.

2. Verify that a test lamp illuminates between the ground circuit terminal 4 and B+.

• If the test lamp does not illuminate

1. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If the test lamp illuminates
Replace the G10 Cooling Fan Motor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Engine Coolant Fan Replacement (2.4L LEA) Engine Coolant Fan ReplacementEngine Coolant Fan Replacement (2.0L LHU) Engine Coolant Fan Replacement

* Control Module References Control Module References