Circuit/System Description
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.
The hybrid powertrain control module monitors a state of health message that the ECM transmits to verify the ECM is functioning properly. The hybrid powertrain control module is part of the power inverter module, often referred to as the drive motor power inverter module, and is not serviced separately.