FORD 2012 F-550 v.1 - Manual (Page 299)

Although the SST will make some downshifts for you, it will still allow
you to downshift at any time as long as the SST determines that the
engine will not be damaged from over-revving.
The SST will not automatically upshift, even if the engine is approaching
the RPM limit. It must be shifted manually by pressing the + button.
Engine damage may occur if excessive engine revving is held
without shifting.
Hill start assist (HSA)
The hill start assist feature makes it easier to pull away when the vehicle
is on a slope without the need to use the parking brake. When the hill
start assist feature is active, the vehicle will remain stationary on the
slope for up to two seconds after you release the brake pedal. During
this time, you have time to move your foot from the brake to the
accelerator pedal and pull away. The brakes are released automatically
once the engine has developed sufficient drive to prevent the vehicle
from rolling down the slope. This is an advantage when pulling away on a
slope; for example from a car park ramp, traffic lights or when reversing
uphill into a parking space.
WARNING: The hill start assist feature does not replace the
parking brake. When you leave the vehicle, always apply the
parking brake and select first or reverse gear.
Using hill start assist
The hill start assist feature is activated automatically when the vehicle is
stopped on a slope greater than five degrees. The hill start assist feature
operates with the vehicle facing downhill if reverse gear is selected. The
hill start assist feature will not operate if the parking brake is activated.
WARNING: You must remain in the vehicle once you have
activated the hill start assist feature.
Activating hill start assist
1. Press the brake pedal to bring the vehicle to a complete standstill.
Keep the brake pedal pressed.
2. If the sensors detect that the vehicle is on a slope, the hill start assist
feature will be activated automatically.
3. When you remove your foot from the brake pedal, the vehicle will
remain on the slope without rolling away for approximately up to two
seconds. This hold time will automatically be extended if you are in the
process of driving off.
Driving
299
2012 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)