See also:

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

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 ...

Special Application Services
• Severe Commercial Use Vehicles Only: Lubricate chassis components every 5 000 km/3,000 mi. • Have underbody flushing service performed once a year. ...