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 ...

Retrieve My Number
1. Push . System responds: “OnStar ready.” 2. Say “My Number.” System responds: “Your OnStar Hands-Free Calling number is.” ...

Noise Control System
The following information relates to compliance with federal noise emission standards for vehicles with a Gross Vehicle Weight Rating (GVWR) of more than 4 536 kg (10,000 lbs). The noise control syste ...