GM Service Manual Online
For 1990-2009 cars only
Driver Seat Belt Switch: The scan tool displays the current status of the driver seat belt switch. The scan tool will display Active when the driver seat belt is buckled and Inactive when the belt is unbuckled.

Passenger Seatbelt Indicator Commanded: The scan tool displays the commanded state of the passenger seat belt indicator. The scan tool will display On when a passage is detected in the passenger seat and the passenger seat belt is unbuckled. The scan tool will display Off when a passenger is detected in the passenger seat and the passenger seat belt is buckled or when no passenger is detected in the passenger seat.