GMC 2010 Yukon XL Denali Owner's Manual page 204

Resuming a Set Speed
If the cruise control is set at a desired speed and then
the brakes are applied, this shuts off the cruise control.
But it does not need to be reset.
Once the vehicle speed is about 40 km/h (25 mph) or
more, press the +RES button on the steering wheel.
The vehicle goes back to the previous set speed and
stays there.
Increasing Speed While Using Cruise
Control
To increase the cruise speed while using cruise control:
Press and hold the +RES button on the steering
wheel until the desired speed is reached, then
release it.
To increase vehicle speed in small increments,
press the +RES button. Each time this is done,
the vehicle goes about 1.6 km/h (1 mph) faster.
4-10
Reducing Speed While Using Cruise
Control
To reduce your speed while using cruise control:
Press and hold the SET button on the steering
wheel until the desired lower speed is reached,
then release it.
To slow down in very small amounts, press the
SET button on the steering wheel briefly.
Each time this is done, the vehicle goes about
1.6 km/h (1 mph) slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase your speed.
When you take your foot off the pedal, the vehicle slows
down to the previous set cruise speed.
Using Cruise Control on Hills
How well the cruise control works on hills depends upon
the vehicle speed, load, and the steepness of the hills.
When going up steep hills, you might have to step on
the accelerator pedal to maintain the vehicle's speed.