P0480

DTC P0480 (2.2L and 2.4L)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC P0480
- Cooling Fan Relay Control Circuit




Diagnostic Fault Information






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.


Conditions for Running the DTC

* The ignition is ON.
* The system voltage is between 9-18 volts.
* The relay control circuit is transitioned from OFF to ON, or ON to OFF.



Conditions for Setting the DTC

* An improper voltage level has been detected on the cooling fan relay control circuit.
* The condition must be present for a minimum of 30 seconds.



Action Taken When the DTC Sets

DTC P0480 is a Type B DTC.


Conditions for Clearing the DTC

DTC P0480 is a Type B DTC.


Reference Information
Schematic Reference

Engine Cooling Schematics (Electrical Diagrams)
Connector End View Reference

* Component Connector End Views (Connector Views)
* Electrical Center Identification Views (Application and ID)

Description and Operation

Cooling Fan Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Ignition ON, command the relay ON and OFF with a scan tool. Feel or listen to verify that the relay turns ON and OFF with each command.


Circuit/System Testing

1. Ignition OFF, disconnect the relay.

Important: This driver may not illuminate some test lamps due to current protection. Connect two lamps in series to reduce current.


2. Ignition ON, connect two test lamps in series between the positive terminal at the battery and the relay control circuit terminal 86 at the relay connector.
3. Command the relay ON and OFF with a scan tool. A test lamp should turn ON and OFF when changing between the commanded states.

• If a test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
• If the test lamps are always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

4. Connect a 30A fused jumper wire between the positive voltage terminal at the battery and the fan voltage supply circuit terminal 87 and verify fan activation.

• If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fan.

5. Ignition ON, connect a 30A fused jumper wire between the relay switch voltage supply circuit terminal 30 and the fan voltage supply circuit terminal 87 and verify fan activation.

• If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and it's fuse is open, test all connected components and replace as necessary.

6. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal 85 and ground.

• If the test lamp does not illuminate, test the relay coil voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.

7. If all circuits and the ECM test normal, replace the relay.



Repair Instructions

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

* Cooling Fan and Shroud Replacement (LE5, L61) (Service and Repair)Cooling Fan and Shroud Replacement (LNF) (Service and Repair)
* Fan Shroud Replacement (Service and Repair)
* Engine Control Module Replacement (Service and Repair) for the 2.2L engine
* Engine Control Module Replacement (Service and Repair) for the 2.4L engine