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, 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 module functions will run only when the 42 volt accessory DC power control module enable is active through serial data.

The accessory DC power control module continuously monitors the status of its 42 volt circuitry. When the ignition key is first turned to RUN, some diagnostics are performed on this circuitry. When the engine is started, and the 42 V enable command is received by the accessory DC power control module, additional diagnostics are run.