Accessory DC Power Control Module

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.

Location

The accessory DC power control module is affixed to and located underneath the power inverter module. It is fastened to the power inverter module with external mounting fasteners and 2 internal high voltage circuit connection fasteners. The accessory DC power control module shares a coolant passage with the power inverter module and as such is gasketed to the power inverter module.

Operating Functions

The accessory DC power control module is the device which converts high voltage (300V) direct current (DC) to low voltage (12V) DC for accessory electrical operation and to charge the 12 volt accessory battery. The accessory DC power control module also converts high voltage DC to intermediate (42V) DC to supply the electric power steering system with voltage. The accessory DC power control module is capable of supplying up to 175 Amps of 12 volt DC and up to 50 Amps of 42 volt DC. In Jump Assist mode the accessory DC power control module converts 12 volt DC to high voltage DC to charge the high voltage hybrid batteries. The accessory DC power control module is capable of supplying up to 2.7 Amps at 290 volts DC on the high voltage circuit when operating in Jump Assist. An external 12V DC battery charger is required during the Jump Assist mode because the accessory DC power control module and vehicle controllers may draw as much as 80 Amps of current from the vehicles 12 volt DC system.

Communication and Hosted Diagnostics

The accessory DC power control module has internal diagnostic tests that run at both power-up and during operation. All DTCs from the accessory DC power control module are reported to and hosted by the hybrid powertrain control module. The accessory DC power control module communicates directly only with the hybrid powertrain control module and only on the high speed hybrid GMLAN communication circuit.

Circuit Inputs

Inputs supported by the accessory DC power control module include the high voltage and 12 volt circuits. The accessory DC power control module also monitors various internal components for current, voltage and temperature. The accessory DC power control module is also connected to the high speed hybrid GMLAN communication circuit. An individual 12 volt discrete circuit powers ON the accessory DC power control module. The accessory DC power control module will not begin conversion of voltage however, until the appropriate GMLAN enable signal is communicated to it by the hybrid powertrain control module.

Circuit Outputs

The only outputs supported by the accessory DC power control module are the 12 volt and 42 volt conversion during normal vehicle operation and high voltage conversion during Jump Assist.