WARNING: This page is about a different car, the 2004 Pontiac Sunfire and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Connect the electrical connector to the door jamb switch.
Fig 1: Connecting Rear Door Jamb Switch Electrical Connector
Courtesy of GENERAL MOTORS CORP.
Press inward on the door jamb switch (2) until fully seated in the hinge pillar.