Circuit/System Description
WARNING: This page is about a different car, the 2012 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.
The exterior passenger door handle contains a small sensor which allows a person to lock the vehicle doors from the outside without using the remote keyless transmitter. The keyless entry control module monitors the voltage level on the passenger door handle switch signal circuit, when the switch is pressed, the voltage in the signal circuit will drop and the keyless entry control module will then send a serial data message to the BCM to command all the doors to lock.