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:
Liftgate
To open the liftgate the vehicle must be in P (Park). Press the touch pad under the liftgate handle. To close the liftgate, use the pull cup or pull strap as an aid.
Power Liftgate
On vehicles with ...
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 on page 9‑64.
Added electrical equipment ...
Blind Spot Mirrors
The blind spot mirror is a small convex mirror built into the upper and outer corner of both outside mirrors. It can show objects that may be in the vehicle's blind zone.
Driving with the Blind Spot ...