GM Service Manual Online
For 1990-2009 cars only

Retained Accessory Power (RAP)

The BCM monitors the ignition switch position, battery condition, and each door ajar/open switch status to determine whether RAP should be initiated or terminated. RAP is controlled with 2 different methods; serial data and relay control. Some modules receive a RAP message from the body control module (BCM) over the serial data circuits. Serial data controlled RAP is deactivated as required by their modules RAP power mode operation. Other subsystems are activated directly by the BCM through a RAP relay. Components and systems that are active in RAP are also activated anytime the ignition is any position other than OFF regardless of the door switch signals.

Relay Controlled RAP

The BCM keeps the RAP relay energized during all power modes, except Off-Awake and Crank. The relay is also energized for approximately 10 minutes after shutting the ignition OFF and removing the key, providing no door is opened.

Relay controlled RAP will end when one of the following conditions is met:

    • The BCM receives an input from any door ajar or open switch indicating the opening of any door after the ignition key is out of the ignition.

       Important: If the BCM is receiving any door ajar or open signal from those switches when the ignition key is turned OFF, RAP will not initiate.

    • The BCM internal timer for the RAP expires after approximately 10 minutes.
    • The BCM detects a decrease in battery capacity below a prescribed limit.

Systems powered by the accessory relay during the retained accessory power (RAP) power mode are as follows:

    • Power windows
    • Sunroof

Serial Data Controlled RAP

RAP systems controlled by serial data are as follows:

Radio

Radio RAP activation/termination is the same as relay operation with 1 exception; the only door switch that will turn off the radio during RAP is the driver door open switch.