Ford Expedition Owner's Manual page 248

Driving
• If the driving condition is severe and your foot is not on the brake, the
brake pedal may move as the systems applies higher brake forces. You
may also hear a whoosh of air from under the instrument panel during
this severe condition.
• The brake pedal may feel stiffer than usual.
Traction control system (TCS)
The TCS is a driver aid feature that helps your vehicle maintain traction
of the wheels, typically when driving on slippery and/or hilly road
surfaces, by detecting and controlling wheel spin.
Excessive wheel spin is controlled in two ways, which may work
separately or in tandem: engine traction control and brake traction
control. Engine traction control works to limit drive-wheel spin by
momentarily reducing engine power. Brake traction control works to limit
wheel spin by momentarily applying the brakes to the wheel that is
slipping. Traction control is most active at low speeds.
During TCS events, the stability control light in the instrument cluster
will flash.
If the TCS system is activated excessively in a short period of time, the
braking portion of the system may become temporarily disabled to allow
the brakes to cool down. In this situation, TCS will use only engine
power reduction or transfer to help control the wheels from
over-spinning. When the brakes have cooled down, the system will regain
all features. Anti-lock braking, RSC , and ESC are not affected by this
condition and will continue to function during the cool-down period.
The engine traction control and brake traction control system may be
deactivated in certain situations. See the Switching off traction control
section following.
Electronic stability control (ESC)
Electronic stability control (ESC) may enhance your vehicle's directional
stability during adverse maneuvers, for example when cornering severely or
avoiding objects in the roadway. ESC operates by applying brakes to one or
more of the wheels individually and, if necessary, reducing engine power if
the system detects that the vehicle is about to skid or slide laterally.
During ESC events, the stability control light in the instrument cluster
will flash.
Certain adverse driving maneuvers may activate the ESC system, which
include but are not limited to:
• Taking a turn too fast
248
2012 Expedition (exd)
Owners Guide, 1st Printing
USA (fus)