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 time-out limit.
The modules listed below all receive a RAP message from the body control module
(BCM) over the serial data circuits. The BCM monitors the ignition switch position,
battery condition and passenger compartment door status to determine whether RAP should
be initiated. The BCM 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 BCM receives an input (as a hard wired input from the door switches)
indicating the opening of a passenger compartment door. |
| • | The BCM receives a message from its internal timer indicating the end
of the RAP period after 10 minutes. |
| • | The BCM detects a decrease in battery capacity below a prescribed limit. |
| • | The transition from OFF to RUN/ON or ACC of the ignition switch. |
The BCM then sends a serial data message to the listed devices ending the RAP
function.
The devices receiving serial data messages for RAP functions are:
| • | Driver information center (DIC) |
| • | Digital radio receiver (DRR), if equipped |
| • | Instrument panel cluster (IPC) |
| • | Vehicle communication interface module (VCIM), if equipped |
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 time-out limit.
The body control module (BCM) activates the RAP relay in either the RAP function
as described above or if the BCM detects a RUN/ON or accessory power mode. This provides
power for the following:
| • | The sunroof control module, if equipped |
The BCM deactivates the RAP relay to end the RAP function when it ends the
RAP function as outlined in the previous text.
