Circuit/System Description

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

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 drive motor generator control module through the communication circuit. The drive motor generator control module is the host controller for diagnostic trouble code (DTC) information.

The drive motor generator battery control module has several methods of monitoring the total voltage values of the hybrid batteries. The drive motor generator battery control module monitors the calculated battery voltage and the terminal voltage. The calculated voltage represents the sum of the voltages from the 22 individual battery measurements, and the terminal voltage represents the total DC bus voltage as measured on the output side of the high voltage contactors. The drive motor generator battery control module compares these two voltage readings and looks for a difference. The drive motor generator battery control module also monitors the terminal voltage for both over voltage and under voltage conditions.