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.
The body control module (BCM) monitors the ignition switch position,
battery condition and passenger compartment door status to determine whether
RAP should be initiated. If the ignition switch transitions from RUN/ON
to OFF, the battery level is within the acceptable range and the passenger
compartment doors are closed, the BCM closes the RAP relay. This provides
power for the following:
| • | The sunroof (if equipped) |
| • | The OnStar® System (if equipped) |
The BCM turns OFF the RAP function and opens the RAP relay when one
of the following conditions are met:
| • | The BCM senses the opening of any door (or the liftgate on utility
vehicles) in the passenger compartment. |
| • | The BCM detects a decrease in battery capacity below a prescribed
limit. |
| • | The BCM receives a message from its internal timer indicating
the end of the RAP period after 20 minutes. |
| • | The transition from OFF to RUN/ON or ACC of the ignition switch |
