GMC Yukon Denali 2015 Owner's Manual page 213

9-8 Driving and Operating
When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
Warning
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill:
1. Apply the brakes to stop the
vehicle, and then apply the
parking brake.
2. Shift into P (Park) and then
restart the engine.
If driving uphill when the
vehicle stalls, shift to
R (Reverse), release the
parking brake, and back
straight down.
Never try to turn the vehicle
around. If the hill is steep
enough to stall the vehicle,
it is steep enough to cause
it to roll over.
If you cannot make it up the
hill, back straight down
the hill.
Never back down a hill in
N (Neutral) using only the
brake.
The vehicle can roll
backward quickly and you
could lose control.
If driving downhill when the
vehicle stalls, shift to a
lower gear, release the
parking brake, and drive
straight down the hill.
3. If the vehicle cannot be restarted
after stalling, set the parking
brake, shift into P (Park), and
turn the vehicle off.
3.1. Leave the vehicle and
seek help.
3.2. Stay clear of the path the
vehicle would take if it
rolled downhill.
Avoid turns that take the vehicle
across the incline of the hill.
A hill that can be driven straight
up or down might be too steep to
drive across. Driving across an
incline puts more weight on the
downhill wheels, which could
cause a downhill slide or a
rollover.
Surface conditions can be a
problem. Loose gravel, muddy
spots, or even wet grass can
cause the tires to slip sideways,
downhill. If the vehicle slips
sideways, it can hit something
that will trip it a rock, a rut,
etc. and roll over.