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Other Features

PA1627 X3-45 Operator’s Manual

5-24

ANTILOCK BRAKING SYSTEM

(ABS),

TRACTION CONTROL SYSTEM (TCS) &
ELECTRONIC STABILITY CONTROL (ESC)

ANTILOCK BRAKING SYSTEM (ABS)

The purpose of the Antilock Braking System
(ABS) is to maintain vehicle stability and control
during braking and to minimize the stopping
distance in any road condition.

On slippery roads and more generally in
emergency situations, over-braking frequently
induces wheel locking. Wheel locking greatly
increases breaking distance on any road
surface. Locked wheels also impede directional
control and cause severe tire abrasion. An
antilock braking system provides maximum
braking performance while maintaining
adequate control on slippery roads.

The basis of ABS is constant monitoring of
wheel parameters during braking. Sensors on
each wheel of the front and drive axles
constantly measure wheel speed during braking.
This information is transmitted to a four-channel
electronic processor which senses when any
wheel is about to lock. Modulating valves
quickly adjust brake pressure (up to 5 times
every second) to prevent wheel lock. Each
wheel is therefore controlled according to the
available grip.

In this way, the vehicle is brought to a stop in the
shortest possible time while remaining stable
and under the driver's control.

WARNING

Vehicles following ABS-equipped vehicles
may not be able to brake as fast on slippery
roads.

TRACTION CONTROL SYSTEM (TCS)

TCS controls wheel spin during vehicle
acceleration to improve traction.



The TCS system will intervene automatically
and apply braking pressure to a spinning
wheel transferring engine power to the other
drive wheel that have better traction. This
feature is active only at speeds below 25
mph (40 km/h).



If all of the drive wheels begin to spin, the

TCS system will reduce engine throttle to
improve traction at all of the drive wheels.

If drive wheels begin to lose traction during
acceleration, TCS will engage automatically to
assist the driver in accelerating the vehicle. The
TCS/ESC lamp will flash rapidly to let you know
whenever TCS is actively functioning.

ELECTRONIC STABILITY CONTROL (ESC)

The ESC stability system is an optional feature
for ABS-equipped vehicles that reduces the risk
of rollovers and loss of control. The ESC system
features include the RSP Roll Stability Program
and Yaw Control.

The RSP system counteracts the tendency of a
vehicle to tip over while changing direction
(typically, while turning).

To reduce the risk of rollover, the RSP system
detects potential rollover conditions and slows
the vehicle both by reducing engine throttle (and
hence, engine torque) and by applying service
brakes as needed at the appropriate wheels.

WARNING

During an RSP system intervention, the
vehicle

automatically decelerates

. The RSP

system can slow the vehicle with or

without

you applying the brake pedal, and even
when you are applying the throttle

During an RSP system intervention, you can
always use your service brake pedal to increase
the braking pressure that will be applied. However,
if you were to apply less braking pressure than
needed or even if you release the brake pedal
entirely during an intervention, the RSP system will
continue to apply the necessary amount of braking
pressure automatically to the appropriate wheels to
mitigate a potential rollover.

Yaw Control is a feature that reduces the risk of
loss of control. If a vehicle’s tires start to slide
during a turn, Yaw Control counteracts the
tendency of that vehicle to spin (or yaw), thereby
reducing the risk of loss of control. Many factors,
including road conditions, load distribution and
driving behavior, can contribute to the
development of a spin.

WARNING