GM Service Manual Online
For 1990-2009 cars only

Seat belts are the primary means of occupant restraint. Seat belts help to keep the occupant inside the passenger compartment and to ride down the crash forces more gradually during the following events.

    • Frontal impact type crashes.
    • Rear impact type crashes.
    • Side impact type crashes.
    • Roll over type crashes.

All seat belts have emergency locks in the retractors. During normal operation, the retractors remain unlocked to allow free movement of the occupant's upper body under normal driving conditions. The seat belt webbing is locked to position by a pendulum that causes a locking bar to engage a cog on the spool of the retractor mechanism under the following conditions.

    • The rapid extraction of the seat belt webbing fro the retractor.
    • The speed of the vehicle changes abruptly.
    • The direction of the vehicle changes abruptly.
    • The vehicle is on a steep upgrade or a downgrade.

The seat belts have an automatic locking (cinch) feature. The cinch feature is activated when the seat belt webbing is completely extended from the retractor. The cinch feature will not allow the webbing to extend from whatever position it is allowed to retract. It is recommended that the cinch feature is used when securing a child seat. The cinch feature is canceled by allowing the webbing to be completely wound back into the retractor. After the cinch feature is canceled, the webbing is unlocked and will extend from the retractor.

The seat belts have a comfort lock feature which prevents full retraction of the webbing allowing the user to lock the seat belt into a comfortable position. The feature is activated by slowly allowing the webbing to wind in to the retractor. The user can readjust the comfort lock during vehicle operation. The feature is canceled by extending the webbing from the retractor or the user's door is opened allowing the webbing to fully retract to the stowed position.