Overview

Fan Control Circuit

Circuit Description

The engine control module (ECM) provides a signal to the fan control solenoid to turn the engine fan on and off. There are two types of fans supported by this signal; variable speed and ON/OFF. The INSITE™ electronic service tool can be used to determine which fan type is currently set up for use. The fan control circuit varies by OEM. Certain OEMs will use a solenoid return that is wired to the ECM or use a return that goes to engine block or chassis ground.

Component Location

The fan control location varies by original equipment manufacturer (OEM). Refer to the OEM service manual to determine the location.

Shop Talk

The fan control logic can be adjusted with the INSITE™ electronic service tool. There are two choices: 12 or 24-VDC ON, or 0-VDC ON. For proper fan operation, the fan control logic setup with INSITE™ electronic service tool must match the hardware configuration on the vehicle.

This fault code is logged when the ECM commands 12 or 24-VDC to the fan control, but the voltage on the fan control signal circuit is less than 12 or 24-VDC. The low voltage on the signal circuit usually indicates a short circuit to ground in the harness.

If Fault Code 245 is still active after completing the following troubleshooting steps, consult the OEM service manual for procedures to check the fan control circuit for a short circuit to ground.

Refer to Troubleshooting Fault Code t05-245.

Last Modified: 29-Nov-2012

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