Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push 
to try the call again or try again after driving a few miles into another cellular area.
See also:
Courtesy Transportation Program (U.S. and Canada)
To enhance your ownership experience, we and our participating dealers are proud to offer Courtesy Transportation, a customer support program for vehicles with the Bumper-to-Bumper (Base Warranty Cove ...
Ultrasonic Parking Assist
If available, Ultrasonic Rear Parking Assist (URPA) system uses sensors on the
rear bumper to assist with parking and avoiding objects while in R (Reverse). It
operates at speeds less than 8 km/h ...
Going & Stopping
The biggest drawback I found with the Yukon was the powertrain. A
380-horsepower, 6.2-liter V-8 is standard in the Denali, but it was sluggish in
almost every passing situation I could simulate. T ...