Limit Switch
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The limit switch is part of the sunroof motor assembly and is to signal the sunroof module when the sunroof glass is closed flush with the roof or when it reaches the comfort stop during the express open feature.
As the limit switch closes, the sunroof limit switch low reference circuit is applied to the sunroof limit switch soft stop signal circuit, pulling the 12 volt reference down to 0 volts. The 0 volts at the sunroof limit switch soft stop signal input indicates that the sunroof glass has either reached the flush close or the comfort stop position and that the voltage will be removed from the motor control circuits.