Anti-lock brake system (abs), Using abs, Abs warning lamp – FORD 2011 Expedition User Manual
Page 244: Abs p ! brake
Anti-lock brake system (ABS)
On ABS-equipped vehicles, a noise from the hydraulic pump motor and
pulsation in the pedal may be observed during ABS braking events. Pedal
pulsation coupled with noise while braking under panic conditions or on
loose gravel, bumps, wet or snowy roads is normal and indicates proper
functioning of the vehicle’s anti-lock brake system. The ABS performs a
self-check after you start the engine and begin to drive away. A brief
mechanical noise may be heard during this test. This is normal. If a
malfunction is found, the ABS warning light will come on. If the vehicle
has continuous vibration or shudder in the steering wheel while braking,
the vehicle should be inspected by an authorized dealer.
The ABS operates by detecting the onset of wheel lockup during brake
applications and compensates for this tendency. The wheels are
prevented from locking even when the brakes are firmly applied.
Using ABS
• In an emergency or when maximum efficiency from the four-wheel ABS
is required, apply continuous force on the brake. The four-wheel ABS
will be activated immediately, thus allowing you to retain steering
control of your vehicle and, providing there is sufficient space, will
enable you to avoid obstacles and bring the vehicle to a controlled stop.
• The anti-lock system does not always reduce stopping distance.
Always leave enough room between your vehicle and the vehicle in
front of you to stop.
• We recommend that you familiarize yourself with this braking
technique. However, avoid taking any unnecessary risks.
ABS warning lamp
The ABS warning lamp in the
instrument cluster momentarily
illuminates when the ignition is
turned on. If the light does not
illuminate momentarily at start up,
remains on or continues to flash, the ABS needs to be serviced.
With the ABS light on, the anti-lock
brake system is disabled and normal
braking is still effective unless the
brake warning light also remains
illuminated with parking brake
released. If your brake warning lamp illuminates, have your vehicle
serviced immediately.
ABS
P
!
BRAKE
Driving
244
2011 Expedition (exd)
Owners Guide, 1st Printing
USA (fus)