GM Service Manual Online
For 1990-2009 cars only

The body control module (BCM) controls the retained accessory power (RAP) feature. The RAP feature allows for the operation of the following components for 10 minutes (or until a vehicle door opens) after the ignition switch turns from the ON or ACC position to the LOCK position:

    • The radio
    • The power windows
    • The power sunroof (if equipped)

The BCM interfaces with the vehicle's power distribution through the RAP relay. The RAP relay allows the BCM to control the application of power to the RAP relay controlled feed circuit. The RAP relay controlled feed circuit provides power to the power feed circuit for the power windows, the radio, and the power sunroof, if equipped.

When the ignition switch is in either of the following positions, the BCM energizes the RAP relay by suppling ground to the RAP relay control circuit:

    • ACC
    • RUN

The BCM turns OFF the RAP relay when the ignition switch is in the START position. This action disables the RAP feature during engine cranking .

When the ignition switch turns from the RUN or ACC position to the LOCK position, with all of the vehicle doors closed, the BCM leaves the RAP relay energized for 10 minutes or until any vehicle door opens. (The BCM detects a ground signal in the door ajar input circuits).

The BCM resets the RAP timer when the ignition switch turns from the LOCK position to the ACC or RUN position.