Circuit/System Description

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

The accessory DC power control module supplies the energy that flows between the high voltage, 300 volt, direct current (DC) and intermediate voltage, 42 volt, DC to support the electric power steering. The accessory DC power control module receives a 42 volt enable command from the hybrid powertrain control module over serial data. 42 volt accessory DC power control module functions will run only when the 42 volt accessory DC power control module enable is active on serial data.

Heat is generated in the 42 volt accessory DC power control module primarily through the demand for use of the electronic power steering. The ECM measures the temperature of the power electronics cooling loop and commands the flow of 2 electrical coolant pumps. The accessory DC power control module transfers heat from the 42 volt circuit to the accessory DC power control module heat plate which is then dissipated at the Generator Control Module Coolant Radiator.

Based on the severity of the over temperature condition in the 42 volt circuit, the accessory DC power control module will take actions ranging from notifying the electronic power steering control module of an over temperature condition to completely shutting down 42 volt power conversion.