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 following DTCs are for the starter/generator control module (SGCM) coolant pump relay:
- P0A06 is for the SGCM coolant pump relay control circuit low voltage condition.
- P0A07 is for the SGCM coolant pump relay control circuit high voltage condition.
The SGCM controls the coolant pump operation by applying voltage to the coolant pump relay control circuit with an internal solid state device called a driver. When the SGCM is commanding the relay ON, the voltage of the control circuit should be low, near 0 volts. When the SGCM is commanding the relay OFF, the voltage potential of the control circuit should be high, near 12 volts.
The SGCM monitors the relay control circuit for the following conditions:
- Short to ground
- Short to voltage
- An open circuit
If the SGCM detects an improper voltage level on the coolant pump control circuit, then DTC P0A06 or P0A07 will set and the driver will be disabled.