Retained Accessory Power (RAP) Description and Operation

Retained Accessory Power (RAP) Description and Operation

Retained Accessory Power (RAP) Power Mode

Retained accessory power (RAP) is a power mode that permits the operation of selected customer convenience items for approximately 10 minutes after the ignition switch is turned OFF. RAP power mode is enabled by the body control module (BCM) and controls certain BCM features.

The BCM monitors the ignition switch position, battery voltage and passenger compartment door status to determine whether RAP power mode should enable. If the ignition switch transitions from ON to OFF, the battery voltage is within the acceptable range, and the passenger compartment doors are closed, the BCM enables RAP power mode. After the 10 minutes have elapsed, the BCM will cease to produce the RAP power mode.

Some BCM features, such as the interior courtesy lamps, will function after the 10 minute RAP time limit has elapsed. This is normal and does not mean RAP power mode is malfunctioning. The BCM enables the following functions in RAP power mode:

* The radio
* The sunroof, internal to BCM-if equipped
* The power windows, internal to BCM-if equipped

RAP is disabled when:

* A door is opened.
* The BCM detects low battery voltage.
* The transition of ignition switch from OFF to ON or ACC.
* 10 minutes have elapsed after the ignition was turned OFF.

Important: There may be some functions of the vehicle that are hard-wired straight to the battery; these are the exceptions.

ACC Relay

The accessory (ACC) relay switches the accessory power to the vehicle and also severs as the retained accessory power (RAP) relay when the body control module (BCM) commands a RAP power mode. The ACC relay is installed directly on the BCM and its supply current is derived from the fuse block underhood junction box. The BCM on this vehicle is integrated with a bussed electrical center (BEC), because the BCM and the BEC are integrated. Replacement of the BCM may be the only way to repair certain RAP malfunctions, e.g., internal short to B+ or ground.