User's Manual

12
Optional ATC Mud/Snow (Off-Road) Mode
In some road conditions, the vehicle operator may desire
additional drive wheel slip when ATC is active. The Bendix
®
ESP
®
EC‑80
™
Controller has an optional control mode to
permit this desired performance.
The vehicle operator can activate the Mud/Snow function
with a switch on the dash panel. Alternately, a J1939
message may be used to place the vehicle in this mode.
The ATC/ESP Indicator Lamp will ash steadily at a rate
of once every 2.5 seconds to conrm that the ATC mud/
snow mode is engaged.
To exit the ATC Mud/Snow mode, depress and release the
ATC Mud/Snow switch.
Drag Torque Control Functional Overview
Bendix ESP EC‑80 Controllers have a feature referred to
as drag torque control which reduces wheel slip on a driven
axle due to driveline inertia. This condition is addressed
by increasing the engine torque to overcome the inertia.
Drag torque control increases vehicle stability on low‑
traction road surfaces during down‑shifting or retarder
braking.
FIGURE 13 - YAW CONTROL EXAMPLE
A Real World Example Of How Yaw Control
Operates:
Excessive speed exceeds the threshold, creating a
situation where a vehicle is likely to spin and jackknife.
The Bendix
®
Yaw Control system reduces engine throttle
and selectively applies brakes to reduce the tendency
to jackknife.
FIGURE 12 - RSP EXAMPLE
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.
BENDIX ESP EC-80 ABS WITH STABILITY
CONTROL
Overview
The Bendix ESP system with the EC‑80 Controller reduces
the risk of rollovers, jackkning and other loss‑of‑control
events. Bendix ESP EC‑80 Controllers include Roll
Stability Program (RSP
®
) and Yaw Control (YC) functions.
During operation, the Bendix ESP EC‑80 Controller
constantly compares performance models to the vehicle’s
actual movement, using wheel speed sensors; a lateral
acceleration sensor, a yaw rate sensor, and a steering
angle sensor. 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.