Circuit Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The starter/generator control module (SGCM) coolant pump/fan relay supplies battery voltage to the SGCM coolant pump relay and the SGCM coolant fan relay. The SGCM monitors the temperature of the low side driver for the SGCM coolant pump/fan relay. The temperature sensor of the driver is not serviceable and the data for this sensor is not available on the scan tool. This internal driver temperature sensor aids in detecting a control circuit shorted to ground or a shorted relay coil.