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 drive motor generator battery control module is also referred to as the battery energy control module (BECM). The drive motor generator battery control module will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is communicated from the drive motor generator battery control module to the hybrid powertrain control module (HPCM) through serial data. The hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information.

The hybrid drive motor generator battery contains 3 high voltage contactors. The contactors allow the high voltage DC batteries to be connected to the vehicle or safely contain the DC high voltage within the drive motor generator battery assembly. The 3 contactors are a positive high voltage contactor, negative high voltage contactor, and current limit relay. These contactor/relays close and open in sequence and are controlled by the drive motor generator battery control module. The drive motor generator battery control module monitors the control circuit voltage and 12 V reference circuit internal to the control module to determine if the circuit is operating.