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). � ...

Electronic Range Select (ERS) Mode
ERS or manual mode allows for the selection of the range of gear positions. Use this mode when driving down hill or towing a trailer to limit the top gear and vehicle speed. To use this feature: ...

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