See also:

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 1. Press . The system responds with “Ready” ...

Starting Procedure (Keyless Access)
1. If the vehicle has the keyless access system, the transmitter must be in the vehicle. Put your foot on the brake pedal and push the START button. When the engine begins cranking, let go ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment. Added electrical equipment may interfer ...