FORD 2012 F-550 v.1 - Manual (Page 296)

D (Overdrive) with Tow/Haul On
The tow/haul feature improves transmission operation when towing a
trailer or a heavy load. All transmission gear ranges are available when
using tow/haul.
To activate tow/haul, press the
button on the end of the gearshift
lever.
The TOW HAUL indicator light will
illuminate in the instrument cluster.
Tow/haul delays upshifts to reduce frequency of transmission shifting.
Tow/haul also provides engine braking in all forward gears when the
transmission is in the D (Overdrive) position; this engine braking will
slow the vehicle and assist the driver in controlling the vehicle when
descending a grade. Depending on driving conditions and load
conditions, the transmission may downshift, slow the vehicle and control
the vehicle speed when descending a hill, without the brake pedal being
pressed. The amount of downshift braking provided will vary based upon
the amount the brake pedal is pressed.
Tow/haul may be automatically activated (without pressing the tow/haul
button). This provides engine braking to assist the vehicles braking
system when going downhill and repetitive braking is sensed. Once the
tow/haul mode has been automatically activated it will not automatically
deactivate.
To deactivate the tow/haul feature and return to normal driving mode,
press the button on the end of the gearshift lever. The tow/haul light will
no longer be illuminated.
Tow/haul will also deactivate when the vehicle is powered down for a few
minutes.
WARNING: Do not use the tow/haul feature when driving in icy
or slippery conditions as the increased engine braking can cause
the rear wheels to slide and the vehicle to swing around with the
possible loss of vehicle control.
Driving
296
2012 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)