Reactivation for Subsequent Owners
Push 
and follow the prompts to speak to an Advisor as soon as possible after acquiring the vehicle.
The Advisor will update vehicle records and will explain the OnStar service offers and options available.
See also:
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here are some driving tips to get the best fuel economy possible.
• Avoid fast starts and accelerate smoothly.
• Brake gradually and avoid abrupt stops.
...
Range Selection Mode
Range Selection Mode
The Range Selection Mode switch, if equipped, is located on the shift lever.
To enable the Range Selection feature:
1. Move the column shift lever to the M(Manual) position ...
Muting a Call
During a call, all sounds from inside the vehicle can be muted so that the person on the other end of the call cannot hear them.
• To mute a call, press , and then say “Mute call.” . To cancel ...