See also:

Delayed Locking
When this feature is enabled and the doors are locked with the power lock switch on the instrument panel or front door panels, three chimes sound to signal that the delayed locking feature is in use ...

General Information
For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people. Genuine GM parts have one of these marks: ...

Additional Factors Affecting System Operation
Safety belts help keep the passenger in position on the seat during vehicle maneuvers and braking, which helps the passenger sensing system maintain the passenger airbag status. See “Safety Belts” ...