P0480
DTC P0480, P0691, or P0692 (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.
DTC Descriptors
DTC P0480
- Cooling Fan Speed Output Circuit
DTC P0691
- Cooling Fan Speed Output Circuit Low Voltage
DTC P0692
- Cooling Fan Speed Output Circuit High Voltage
Diagnostic Fault Information
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.
Conditions for Running the DTC
* The ignition voltage is greater than 11 volts.
* The DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 seconds.
Action Taken When the DTC Sets
DTCs P0480, P0691, and P0692 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0480, P0691, and P0692 are Type B DTCs.
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
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
Note: A slight delay may occur before the cooling fan activates.
2. Verify the G10 Cooling Fan Motor activates in each available speed when commanding the cooling fan ON with a scan tool. The cooling fan speed should increase with each command.
• The cooling fan does not activate or increase in speed as commanded
Refer to Circuit/System Testing
• The cooling fan activates and increases in speed as commanded
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
4. Verify the DTC does not set.
• If the DTC sets
Refer to Circuit/System Testing
• If the DTC does not set
5. All OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the G10 Cooling Fan Motor, ignition ON.
2. Verify that a test lamp illuminates between the circuits listed below, and ground.
* B+ circuit terminal 1
* Ignition circuit terminal 2
• If the test lamp does not illuminate and the circuit fuse is good
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 B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
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 infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance, replace the G10 Cooling Fan Motor.
• If the test lamp illuminates
Note: The cooling fan speed output circuit is pulled-up to a voltage within the ECM, 2-3 volts on the output circuit is normal.
3. Connect a DMM, set on the diode setting, between the control circuit terminal 3 and ground.
4. Verify the DMM reading is greater than 2.5 V or displays O.L. with the cooling fan commanded OFF.
• If 2.5 V or less
1. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down.
2. Disconnect the harness connector X1 at the K20 Engine Control Module.
3. Test for infinite resistance between the G10 Cooling Fan Motor control circuit terminal 3 and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance, replace the K20 Engine Control Module.
• If greater than 2.5 V or displays O.L.
5. Command the cooling fan ON to 90 % with a scan tool.
6. Verify the DMM reading is less than 1 V.
• If 1 V or greater
1. Ignition OFF.
2. Disconnect the harness connector X1 at the K20 Engine Control Module, ignition ON.
3. Test for less than 1 V between the G10 Cooling Fan Motor control circuit terminal 3 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V.
4. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down.
5. Test for less than 2 ohms between the G10 Cooling Fan Motor control circuit terminal 3 and the K20 Engine Control Module terminal X1-59.
• If 2 ohms or greater, repair the open in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If less than 1 V
7. 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 for ECM replacement, setup, and programming