When the trunk release switch is pressed, the release switch grounds a switch input to the driver's widow switch. The driver's widow switch sends a signal to the drivers door module by a simple bus interface. The drivers door module sends a class 2 message to the rear integration module which grounds the control circuit of the trunk release relay in the rear fuse block for 1/2 second.
The trunk release relay is hot at all times through a 15 A fuse. When the trunk release relay is energized, the trunk release relay sends battery voltage to the trunk release actuator.