Jeep 2004 Liberty - Manual (Page 234)

ANTI-LOCK BRAKE SYSTEM — IF EQUIPPED
The Anti-Lock Brake System is designed to aid the driver
in maintaining vehicle control under adverse braking
conditions. The system operates with a separate com-
puter 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 Anti-Lock Brake System conducts a low speed self-
test at about 12 mph (20 km/h). If for any reason, your
foot is on the brake when the vehicle reaches 12 mph (20
km/h), this check will be delayed until 25 mph (40
km/h).
The Anti-Lock Brake System pump motor runs during
the self-test and during an ABS stop to provide the
regulated hydraulic pressure. The motor pump makes a
low humming noise during operation, this is normal.
During off-road use, loss of traction can temporarily
defeat the system and cause the warning light to illumi-
nate. Turn the ignition OFF and ON again to restore
Anti-Lock Brake System function.
234 STARTING AND OPERATING