Volt

Accessory DC Power Control Module Description and Operation

The 14 V Power Module, also called the Accessory DC Power Control Module, is located in the rear trunk compartment underneath the floor stowage trim panel. It is attached to the chassis with four fasteners and connected to a plastic cooling duct. The 14 V Power Module has a high-voltage pigtail that passes through the floor of the rear compartment and connects to a high voltage cable that comes from the hybrid battery pack. Also connected to the 14 V Power Module are the 12 V cables + positive and - negative, and a signal connector for serial data.

The 14 V Power Module is an electronic device that takes the place of the generator on a traditional vehicle. On a hybrid or electric vehicle the 14 V power module converts high voltage (300 V) direct current (DC) to low voltage (12 V) DC for accessory electrical operation and to charge the 12 volt battery.

Normally, the 14 V power module only supplies 12 volts DC when the vehicle is under a normal drive cycle. However there are certain instances when the vehicle is being charged through a standard wall socket where the14 V power module operation is required to sustain the 12 volt battery.

The 14 V power module is capable of supplying up to 180 Amps of 12 volt DC.

The 14 V power module has internal diagnostic tests that run at both power-up and during operation. All DTCs from the 14 V power module are reported to and hosted by the hybrid powertrain control module. The 14 V power module only communicates with the hybrid powertrain control module and only over serial data.

Inputs to the 14 V power module include the high voltage and 12 volt circuits. The 14 V power module also has two 12 volt discrete inputs, Accessory and Run/Crank, either one has to be at a high level in order for it to wake up. The 14 V power module is connected to the powertrain expansion communication circuit and communicates with the hybrid powertrain control module. The 14 V power module monitors various internal components for current, voltage and temperature. The 14 V power module will not begin supplying 12 volts DC until:

The 14 V power module will not begin conversion of voltage however, until the appropriate serial data enable signal is sent by the hybrid powertrain control module.

For more information on the 12 V Battery Charging System, refer to Charging System Description and Operation .

The only outputs supported by the 14 V power module are serial data communications and 12 volts DC which powers the 12 volt components in the vehicle and charges the 12 volt battery. Low-voltage 12 V cables on the hybrid/EV vehicle do not require unique colouring or servicing procedures.