Using the “Re-dial” Command
1. Press and hold 
for two seconds.
2. After the tone, say “Re-dial.” Once connected, the person called will be heard through the audio speakers.
See also:
Overview
The GMC Sierra All Terrain HD concept is an exploration of heavy-duty truck
capability combined with greater off-road versatility. It is highlighted by a
bold exterior design, enhanced all-terrain ...
Sun Visors
Pull the sun visor down to block glare. Detach the sun visor from the center
mount to pivot to the side window, or to extend along the rod, if available. ...
Automatic Dimming Mirror
If the vehicle has the automatic dimming mirror, the driver outside mirror automatically adjusts for the glare of the headlamps from behind.
This feature is controlled by the on and off setting on th ...