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:
Roadside Assistance Program (U.S. and Canada)
For U.S.-purchased vehicles, call 1-888-881-3302; (Text Telephone (TTY): 1-888-889-2438).
For Canadian-purchased vehicles, call 1-800-268-6800.
Service is available 24 hours a day, 365 days a year.
...
Onstar.com
The website provides access to account information, manages the OnStar subscription, and allows viewing of videos of each service.
Get subscription plan pricing and sign up for OnStar Vehicle Diagnos ...
Park Brake and P (Park) Mechanism Check
WARNING
When you are doing this check, the vehicle could begin to move. You or others
could be injured and property could be damaged. Make sure there is room in front
of the vehicle in case it be ...