Motor Control Modules

WARNING: This page is about a different car, the 2012 Chevrolet Volt. However, it is still accessible from the selected car via links, so may be relevant.

Location

Both the electric motor generators and the auxiliary transmission fluid pump motor, are located within the transmission. They are each controlled by their own motor control module, each module is a flash-programmable micro-processor. Each motor control module is contained within the drive motor generator power inverter control module assembly. Also contained within the drive motor generator power inverter control module assembly is the hybrid powertrain control module micro-processor.

Operating Functions

The motor control modules operate their respective motors based upon hybrid powertrain control module commands. Each motor control module controls the speed, direction and output torque of its respective traction motor or the auxiliary transmission fluid pump motor through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors.

Communication and Hosted Diagnostics

In addition to the internal serial peripheral interface bus communication circuit that the hybrid powertrain control module and each motor control module control use to communicate, the motor control module controls also communicate on the Hi-speed and Hybrid serial data circuits. The motor control module control does not store its own diagnostic trouble code (DTC) information. The hybrid powertrain control module will store motor control module control associated DTC information for retrieval by a scan tool. The scan tool can communicate directly with each motor control module control in order to retrieve data parameters only.

Circuit Inputs

In addition to data parameters, each motor control module control monitors its respective motor for voltage, current, speed, direction and temperature. Additionally, the motor control module control monitors the insulated gate bipolar transistor components for temperature and proper operation. Some of the motor control module control operation data is shared with the hybrid powertrain control module.

Circuit Outputs

Each motor control module controls its respective insulated gate bipolar transistor driver board that in-turn controls each motor. The motors operate using 3-phase alternating current (AC) electricity. 3 cables connect each motor generator to the power inverter module. Each individually shielded cable is orange in color to alert the technician that the potential for high voltage is present. A single shielded cable connects the auxiliary transmission fluid pump to the power inverter module. This cable contains 3 individual wires that are connected to the 3 phases of the auxiliary transmission fluid pump. The cable is orange in color to alert the technician to the potential presence of high voltage.