Serial Data Control

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

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

Modules listed below receive a RAP message from Dash Integration Module (DIM) module over Class 2 serial data circuit. DIM module monitors ignition switch position, battery condition and passenger compartment door status to determine whether RAP should be initiated. DIM module then sends a message to listed modules telling them that they are in RAP power mode. Modules then support operation of systems under their control as required by their RAP power mode strategy. RAP will wil terminate if:

DIM module receives a serial data message from Driver Door Module (DDM) indicating opening of a passenger compartment door.
DIM module times out RAP period after 10 minutes.
DIM module detects a decrease in battery capacity below a prescribed limit.
Ignition switch transition from OFF to RUN or ACC.

DIM module will send a serial data message to modules to terminate RAP function:

Driver Door Module (DDM)
Radio
Rear Integration Module (RIM)
Vehicle Communication Interface Module (VCIM-Generation F1) or Vehicle Interface Unit (VIU-Generation 2.6)