Retained Accessory Power (RAP)
The retained accessory power (RAP) system allows specific vehicle functions to operate for a specific amount of time after the ignition switch is turned OFF. The BCM monitors the ignition switch position, battery condition, and each door open/closed status to determine whether RAP should be initiated or terminated. RAP is controlled with 2 different methods; serial data and relay control. The relay is internal to the BCM and feeds multiple external components. Some modules receive a RAP message 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 the internal 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.
The BCM sends a serial data power mode message ending the RAP function when one of the following conditions are met:
- The BCM receives an input indicating the opening of any passenger compartment door after the ignition key is out of the ignition.
- The BCM internal timer for RAP expires after approximately 10 minutes.
- The BCM detects a decrease in battery voltage below a calibrated limit.
The only door that will turn off the radio during RAP is the driver door. This is a function of the radio and will still turn off after the time limit.