GM Service Manual Online
For 1990-2009 cars only

Serial Data Control of Retained Accessory Power (RAP)

Retained accessory power (RAP) is a vehicle power mode that permits the operation of selected customer convenience items after the ignition switch is turned OFF. These selected items will remain in operation until a passenger compartment door is opened or until the RAP function timer reaches its shut-off limit.

The modules listed below all receive a RAP message from the dash integration module (DIM) module over the serial data circuits. The DIM module monitors the ignition switch position, battery condition and passenger compartment door status to determine whether RAP should be initiated. The DIM module then sends a message to the listed modules telling them that they are in RAP power mode. The modules then support the operation of the systems under their control as required by their RAP power mode strategy.

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

    • The DIM module receives an input as a serial data message from the driver door module (DDM) indicating the opening of a passenger compartment door.
    • The DIM module receives a message from its internal timer indicating the end of the RAP period after 10  minutes.
    • The DIM module detects a decrease in battery capacity below a prescribed limit.
    • The transition from OFF to RUN/ON or ACC of the ignition switch.

The DIM module then sends a serial data message to the listed modules ending the RAP function.

The modules receiving serial data messages for RAP functions are:

    • The driver door module (DDM)
    • The radio
    • The rear integration module (RIM)
    • The vehicle communication interface module (VCIM)

Relay Control of Retained Accessory Power (RAP)

Retained accessory power (RAP) is a vehicle power mode that permits the operation of selected customer convenience items after the ignition switch is turned OFF. These selected items will remain in operation until a passenger compartment door is opened or until the RAP function timer reaches its shut-off limit.

When the RIM module is in the RAP function as described above, it closes the RAP relay. This provides power during the RAP period for the components supplied by the RAP relay.

The RIM module opens the RAP relay to end the RAP function when it ends the RAP function as outlined in the previous text.