Peterbilt 325 2017, Operator'S Manual

Page: 168 / 392

OPERATING THE BRAKE SYSTEM
Advanced ABS with Stability
Control
This vehicle may be equipped with
Electronic Stability Control (ESC). ESC
is a feature for ABS-equipped vehicles
that reduces the risk of rollovers,
jackknifing and other loss of control
situations. ESC features include Roll
Stability Program (RSP) and Yaw
Control.
During operation, the ECU of the
ESC system constantly compares
performance models to the vehicle’s
actual movement, using the wheel
speed sensors of the ABS system,
as well as lateral, yaw, and steering
angle sensors. If the vehicle shows a
tendency to leave an appropriate travel
path, or if critical threshold values are
approached, the system will intervene
to assist the driver.
Roll Stability Program
RSP, an element of the overall ESC
system, addresses rollover conditions.
In the case of a potential roll event,
the ECU will override the throttle
and quickly apply brake pressure at
all wheel ends to slow the vehicle
combination. The level of braking
application during an RSP event will
be proportional to roll risk.
A Real World Example of How the
RSP System Operates
Excessive speed for road conditions
creates forces that exceed the
threshold at which a vehicle is likely to
rollover on a higher-friction surface.
The system automatically reduces
engine torque and applies the service
brakes (based on the projected rollover
risk) to reduce the vehicle speed,
thereby reducing the tendency to roll
over.
RSP Example
4-28
Y53-6060-1C1 (03/17)
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