There is a driver seat belt reminder light on the instrument cluster.

When the vehicle is started, this light flashes and a chime may come on to remind the driver to fasten their seat belt. Then the light stays on solid until the belt is buckled.
This cycle may continue several times if the driver remains or becomes unbuckled while the vehicle is moving.
If the driver seat belt is buckled, neither the light nor the chime comes on.
Passenger Seat Belt Reminder Light#09-00-89-008A: Warranty Administration - Labor Operation 0600018 - Personal Property Damage - (May 20, 2013)
Subject:Warranty Administration – Labor Operation 0600018 – Personal Property DamageModels: 2014 and Prior GM Passenger Cars and Light Duty TrucksAttention: GMODC dealers are not authorized to use this bulletin.This bulletin is being revised to add model years, update the Labor Operation Infor ...