Serial Data Control Of Retained Accessory Power

WARNING: This page is about a different car, the 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, 2001 Chevrolet Monte Carlo, and 2001 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

Retained Accessory Power (RAP) is a vehicle power mode that permits operation of selected customer convenience items after ignition switch is turned OFF. These selected items will remain in operation until a passenger compartment door is opened or until RAP function timer reaches its shut-off limit.

Modules listed below all receive a RAP message from Body Control Module (BCM) over serial data circuits. BCM monitors ignition switch position, battery problem and passenger compartment door status to determine whether RAP should be initiated. BCM sends a message to listed modules telling them that they are in RAP power mode. Modules support operation of systems under their control as required by their RAP power mode strategy.

RAP will end when one of following conditions are met:

BCM receives an input (as a hard wired input from door switches) indicating opening of a passenger compartment door.
BCM receives a message from its internal timer indicating end of RAP period after 10 minutes.
BCM detects a decrease in battery capacity below a prescribed limit.
Transition from OFF to RUN or ACC of ignition switch.

The BCM sends a serial data message to listed devices ending RAP function.

The devices receiving serial data messages for RAP functions are:

Auxiliary power drop connector.
Driver Information Center (DIC).
Instrument Panel Cluster (IPC).
Radio.
Remote CD player (if equipped).
Vehicle Interface Unit (VIU), if equipped.