See also:

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. ○ The ignition should turn to LOCK/OFF only when the shift lever is in P (Park ...

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 ...

Four-Wheel Drive
If the vehicle has Four-Wheel Drive, you can send the engine's driving power to all four wheels for extra traction. ...