Volt

Drive Motor Generator Control Module Cooling System Description and Operation

This vehicle is equipped with three fully independent cooling systems. The power electronics cooling system is dedicated to cooling the battery charger and the power inverter module. The battery cooling system is dedicated to cooling and heating the high-voltage battery. The engine cooling system is dedicated to cooling the engine and providing heat to the passenger compartment.

The power electronics cooling system uses a radiator, two 12 volt pulse width modulated (PWM) radiator fans, a 12 volt coolant pump and to cool down the Drive Motor Generator Power Inverter Module (PIM) and the Drive Motor Battery Charger. The Vehicle Integration Control Module (VICM) activates the coolant pump and monitors a temperature sensor in the power electronics radiator. The VICM also signals the Engine Control Module (ECM) to operate the radiator fans in response to the power electronics cooling system temperature. The coolant pump will be activated when the vehicle is on and during charging. The power electronics radiator is combined with the battery radiator to form one radiator.

The power electronics cooling system circulates a pre-mixed Dexcool® which is a 50/50 mixture of Dexcool and de-ionised water. Deionised water is required for high-voltage isolation and to prevent corrosion from affecting heat sink performance. Always use pre-mixed coolant and never use tap water in the power electronics coolant system.