Section 427 (Power Liftgate System): Chime/Thermistor: Operation
WARNING: This page is about a different car, the 2004 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.
The chime function is activated by a hardwired connection to the power liftgate control module. The thermistor portion provides a outside temperature signal to the power liftgate control module. As the outside temperature increases the resistance reading increases, as temperature decreases the resistance reading decreases.