Accessory Delay Module: Description and Operation

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 RUN or ACC 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 circuit 75. Circuit 75 provides power to the following circuits:
^ Circuit 43 - Radio
^ Circuit 143 - Power windows, and the power sunroof, if equipped

When the ignition switch is in either of the following positions, the BCM energizes the RAP relay by grounding circuit 707:
^ 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 the engine crank and bulb test.

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 circuit 49 or circuit 727).

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

Diagnostic Trouble Codes (DTCs)
The BCM may set the following DTCs related to the RAP:
^ DTC B1477 RAP Relay Circuit Shorted to GND or Open
^ DTC B1478 RAP Relay Circuit Shorted to B+

Refer to Body Control Module Diagnostic Information in Body Control System for diagnostic procedures regarding these DTCs. Testing and Inspection