Cooling Fan Inoperative
Cooling Fan Inoperative (2.2L and 2.4L)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The engine control module (ECM) grounds the low speed relay, which is relay 1, and the high speed relay, which is relay 2, control circuits through an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line that is monitored by the ECM. When the ECM is commanding a component ON, the voltage potential of the control circuit should be low, near 0 volt. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the ECM detects that the actual state of the control circuit does not match the expected state, a DTC will set.
Reference Information
Schematic Reference
Engine Cooling Schematics (Electrical Diagrams)
Connector End View Reference
* Master Electrical Component List
* Component Connector End Views
Description and Operation
Cooling Fan Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
* Electrical Center Identification Views
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. If DTCs P0480 or P0481 are set, then perform those diagnostics first.
2. Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
1. Ignition OFF, disconnect the affected relay.
2. Connect a 30A fused jumper wire between the positive voltage terminal at the battery and the fan voltage supply circuit terminal and verify fan activation.
* Cooling fan relay 1 or cooling fan relay 2 = terminal 87
* Cooling fan series/parallel relay = terminal 87A
• 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, test the fan ground circuit for an open/high resistance. If the fan did not activate and the circuits test normal, replace the fan.
3. 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.
4. If the fan and all circuits test normal, replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
* Cooling Fan and Shroud Replacement (2.2L (L61), 2.4L (LE5)) Service and Repair
* Fan Shroud Replacement (Service and Repair)
* Control Module References
Repair Verification
Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that each fan turns ON and OFF with each command.