Bendix Automatic Traction Control (Atc) - Electronic Stability Control (Esc); Components; Controller's Abs Function; Controller's Atc Function - PREVOST H3-41 Maintenance Manual

23. BENDIX AUTOMATIC TRACTION
CONTROL (ATC) – ELECTRONIC STABILITY
CONTROL (ESC)
In addition to the ABS function, vehicle is
equipped with a Traction Control System (TCS)
feature. This feature is provided by the Bendix
ESP EC-80 controller. Bendix refers to this
feature as Automatic Traction Control (ATC).
Bendix ATC can improve vehicle traction during
acceleration, and
accelerating through
Engine Torque Limiting (ETL) where the ECU
communicates with the engine's controller and/or
Differential Braking (DB) where individual
wheel brake applications are used to improve
vehicle traction.
The ESP EC-80 model controller also provides
an ABS-based Electronic Stability Control (ESC)
feature. Bendix refers to it as ESC Electronic
Stability Control.
The Bendix ESC system is an ABS-based
stability system that enhances vehicle stability by
both reducing engine throttle and by applying
vehicle braking based
dynamics
ESC stability system consists of Yaw Control
(YC) and Roll Stability Program (RSP) features.
DANGER
Bendix ESC system may reduce the vehicle
speed automatically.
ESC can make the vehicle decelerate
automatically. ESC can slow the vehicle with
or without the operator applying the brake,
and even when the throttle is being applied.
CAUTION
Even with ESC-equipped vehicles, the driver
remains responsible for ensuring vehicle
stability during operation.
23.1

COMPONENTS

23.1.1 EC-80 controller's ABS function
lateral stability while
curves. ATC utilizes
on actual vehicle
PA1621 Maintenance Manual All Series | Revised June 2020
SECTION 12: BRAKE AND AIR SYSTEM
• Six (6) Bendix
®
sensors. Each sensor is installed with a
Bendix Sensor Clamping Sleeve;
Five (5) Bendix
•
Valves (M-40QR);
Dash-mounted
•
Lamp;
Service brake relay valve;
•
Dash-mounted trailer ABS Indicator Lamp.
•
23.1.2 EC-80 controller's ATC function
• Drive axle traction control valve;
• TCS status/indicator icon in the DID;
• Dash-mounted TCS Mud/Snow switch;
• J1939 serial communication to engine
control module.
23.1.3 EC-80 controller's ESC/RSP function
• Front Axle Traction Control Valve integral
to the service brake relay valve;
• Dash-mounted ESC status/indicator lamp;
•

Bendix SAS-70 Steering Angle Sensor

(mounted to the steering column);
• Bendix YAS-70 Yaw Rate/Lateral Acceler-
ation Sensor (mounted to a cross member
forward of the drive axle);
Brake Demand Sensors (installed in the
•
primary and secondary delivery circuits);
An additional Modulator Valve (Bendix
•
40QR Pressure Modulator Valve) that
TM
controls pressure applied to the trailer
brakes during system intervention.
23.2 BENDIX M-40QR PRESSURE
MODULATOR VALVE
This Bendix M-40QR (quick release) Pressure
Modulator Valve (PMV) is operated by the EC-80
controller to modify driver applied air pressure to
the service brakes during ABS, ATC, RSP or YC
activation. The PMV is an electro pneumatic
control valve and is the last valve that air passes
through on its way to the brake chamber. The
modulator hold and release solenoids are
activated to "modulate" or "control" the brake
pressure during an antilock braking event. The
WS-24 wheel speed
TM
Pressure Modulator
®
vehicle ABS Indicator
M-
®
47