Circuit/System Description

WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

The hybrid drive motor generator battery is an air cooled component. The hybrid drive motor generator battery vent fan and relay are located inside the hybrid drive motor generator battery assembly. The hybrid drive motor battery vent fan relay controls the supply voltage to the cooling vent fan motor. The control circuit for the vent fan relay and the vent fan speed are controlled by the battery energy control module (BECM).

The hybrid drive motor generator battery contains 3 high voltage contactor relays that allow the high voltage (HV) DC batteries to be connected to the vehicle. The three HV contactor relays are a positive HV contactor relay, negative HV contactor relay and the inverter current limit relay. These relays close and open in a certain sequence controlled by the BECM. The control circuit for the relays use a common ground and the BECM provide voltage to turn them on and off individually.