DVD Error Messages
Player Error: This message displays when there are disc load or eject problems.
Disc Format Error: This message displays if the disc is inserted with the disc label wrong side up, or if the disc is damaged.
Disc Region Error: This message displays if the disc is not from a correct region.
No Disc Inserted: This message displays if no disc is present when 
DVD or DVD/CD/AUX is pressed on the radio.
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. ...
Customer Satisfaction Procedure (U.S. and Canada)
Your satisfaction and goodwill are important to your dealer and to GMC. Normally, any concerns with the sales transaction or the operation of the vehicle will be resolved by your dealer's sales or ser ...
Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance.
However, if a customer wishes to write or e-mail GMC, the letter should be addressed to:
United States
GMC Customer Assistance ...