Spark

DTC P0480 or P0481

The engine control module (ECM) commands the fans ON in either high speed or low speed, depending on cooling requirements.

In low speed operation, the ECM supplies a ground to the coil side of the low speed fan relay. This energizes the coil and applies voltage directly to the cooling fan through the switch side of the low relay. The fan is connected in series to the cooling fan resistor causing the fan to operate at low speed.

In high speed operation, the ECM supplies a ground to the coil side of the high speed fan relay. When energised, the relay applies voltage directly to the cooling fan through the switch side of the relay. The ECM commands the low speed fan relay OFF and the cooling fan receives full voltage and operates at high speed.

P0480 or P0481 (Without FX3)

P0480 or P0481 (FX3)

P0480

The ECM detects a short circuit to battery, a short circuit to ground, or an open circuit on the low speed cooling fan relay 1 control circuit.

P0481

The ECM detects a short circuit to battery, a short circuit to ground, or an open circuit on the high speed cooling fan relay 2 control circuit.

DTC P0462 and P0463 are Type E DTCs.

DTC P0462 and P0463 are Type E DTCs.

Schematic Reference

Engine Cooling Schematics

Description and Operation

Cooling Fan Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the appropriate fan relay ON and OFF with a scan tool. You should hear the relay click when commanded ON and OFF.
2. 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.

1. Ignition OFF, disconnect the appropriate cooling fan relay.

•	KR20C Cooling Fan Low Speed Relay

•	KR20D Cooling Fan High Speed Relay

2. Ignition ON, verify that a test lamp illuminates between the relay coil ignition circuit terminal 85 and ground.

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

3. Connect a test lamp between the relay control circuit terminal 86 and B+.
4. Command the fan relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

⇒	If the test lamp is always OFF, test the relay coil control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, test or replace the appropriate relay.

•	KR20C Cooling Fan Low Speed Relay

•	KR20D Cooling Fan High Speed Relay

1. Ignition OFF, disconnect the appropriate cooling fan relay.
2. Test for 70-110 Ω between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified range, replace the relay.

4. Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.