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 power inverter control module (PIM) contains two motor control modules (MCMs) and the hybrid powertrain control module (HPCM). Each MCM operates its respective drive motor generator based upon HPCM commands. Each MCM controls the speed, direction and output torque of its respective drive motor generator through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors (IGBTs). Each drive motor generator operates utilizing 3-phase alternating current (ac) electricity. Each IGBT operates a single phase of the drive motor generator. Each phase is individually identified as U, V and W. Each MCM monitors the current of each phase in order to detect PIM overcurrent conditions.

Because all the motor generator phase circuits are electrically joined together, they should each flow about the same amount of current. The MCM performs a mathematical calculation to verify that the phase current sensors are accurate. If the U-V-W phase current sensors indicate about the same amount of phase current, the sum of the calculation should be near zero. If the U-V-W phase currents are not similar, this DTC will set.