For 1990-2009 cars

### Serial Data Control of Retained Accessory Power (RAP)

The modules receive the power mode message from the body control module (BCM) over the serial data circuits, indicating when the retained accessory power (RAP) power mode is current. The BCM monitors the ignition switch position, battery condition and passenger compartment doors status to determine whether RAP should be initiated. The modules then support the operation of the systems under their control as required by their RAP power mode operation.

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

• | The BCM receives an input indicating the opening of any compartment door.

• | The BCM internal timer for the RAP expires after approximately 10 minutes.

• | The BCM detects a decrease in battery capacity below a prescribed limit.

• | The Radio uses an exclusive RAP message that can not be circumvented by any door but the drives door.

The BCM then sends a serial data power mode message ending the RAP function.

The radio is the only module that is controlled by the serial data circuits.

### Relay Control of Retained Accessory Power (RAP)

The body control module (BCM) keeps the accessory relay energized during all power modes, except Off-Awake and Crank.

The devices powered by the accessory relay during the retained accessory power (RAP) power mode are the sunroof and windows.