Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody.
Your dealer or an underbody car washing system can do this. If not removed, rust and corrosion can develop.
See also:
How OnStar Service Works
Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free Calling ar ...
Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and
GPS signal reception. Cellular reception is required for OnStar to send remote signals
to the vehicle. ...
Cooling System
If the vehicle has the Duramax® Diesel engine, see the Duramax® Diesel Supplement for more information.
The cooling system allows the engine to maintain the correct working temperature.
5.3 L En ...