Jeep 2011 Liberty - Owner Manual - Manual (Page 344)

ANTI-LOCK BRAKE SYSTEM
The Anti-Lock Brake System (ABS) is designed to aid the
driver in maintaining vehicle control under adverse
braking conditions. The system operates with a separate
computer to modulate hydraulic pressure, to prevent
wheel lock-up and help avoid skidding on slippery
surfaces.
All vehicle wheels and tires must be the same size and
type, and tires must be properly inflated, to produce
accurate signals for the computer.
WARNING!
Significant over or under-inflation of tires or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.
The ABS conducts a low-speed self-test at about 12 mph
(20 km/h). If you have your foot lightly on the brake
while this test is occurring, you may feel slight pedal
movement. The movement can be more apparent on ice
and snow. This is normal.
The ABS pump motor runs during the self-test at 12 mph
(20 km/h) and during an ABS stop. The pump motor
makes a low humming noise during operation, which is
normal.
WARNING!
• Pumping of the Anti-Lock Brakes will diminish
their effectiveness and may lead to a collision.
Pumping makes the stopping distance longer. Just
press firmly on your brake pedal when you need
to slow down or stop.
(Continued)
342 STARTING AND OPERATING