Radio Messages
Calibration Error: The audio system has been calibrated for the vehicle from the factory.
If Calibration Error displays, it means that the radio has not been configured properly for the vehicle and it must be returned to your dealer for service.
Locked or Loc: One of these messages will display when the THEFTLOCK® system has locked up the radio. Take the vehicle to your dealer for service.
If any error occurs repeatedly or if an error cannot be corrected, contact your dealer.
See also:
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 ...
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a trailer.
See Maintenance Schedule on page 11‑3. Things that are especially important in trailer operation are automatic transmission fluid, e ...
Checking Coolant
The vehicle must be on a level surface when checking the coolant level.
Check to see if coolant is visible in the coolant surge tank. If the coolant
inside the coolant surge tank is boiling, do not ...