GMC 2010 Terrain Owner's Manual page 202

6-64 Infotainment System
Ending a Call
1. Press the hard key.
2. Select Hang Up.
Mute or UnMute a Call
1. Press the hard key.
2. Select the Mute call option to
mute the call.
3. Select the Mute call option again
to unmute the call.
Dual Tone Multi-Frequency
(DTMF) Tones
The in-vehicle Bluetooth system can
send numbers during a call, this is
used when calling a menu driven
phone system.
1. Press the hard key.
2. Select Enter Number option
and enter the number sequence.
The DTMF Tones will be generated
on the network as you enter each
number.