SD-13-4986

SB-10057460-3833

®

The Bendix® ESP® EC‑80™ Controller
Label Shows ECU
Designation

INTRODUCTION
®

®

™

The Bendix ESP EC‑80 Electronic Control Unit (ECU)
is a member of a family of three Bendix® -brand electronic
Antilock Braking System (ABS) devices used to help
improve the braking characteristics of air-braked heavyand medium-duty trucks, tractors, and buses:
1. The Bendix® ABS ESP® ECU uses wheel speed sensors
to monitor four wheel-ends to detect wheel-slip or wheel
lock‑up during braking. The system intervenes when
needed — using Pressure Modulator Valves (PMVs)
to adjust and/or pulse the brake pressure — in order
to optimize the contact between the tires and the road
surface.
2. The Bendix® Automatic Traction Control (ATC) EC‑80™
ECU provides standard ABS; improves vehicle traction
during acceleration; and aid lateral stability while driving
through curves. The Bendix® ATC ECU communicates
with the engine’s Controller to provide Engine Torque
Limiting (ETL), and/or use Differential Braking (DB) to
make brake applications at individual wheels.

FIGURE 1 - THE BENDIX® ESP® EC‑80™ CONTROLLER

The driver is always responsible for the control
and safe operation of the vehicle at all times. The
Bendix ® ABS system does not replace the need
for a skilled, alert professional driver, reacting
appropriately and in a timely manner, and using
safe driving practices.

3. The Bendix ESP EC‑80 Controller provides — in
addition to the ABS and ATC functions described
above — advanced braking features referred to as the
Bendix® ESP® Electronic Stability Program. The Bendix
ESP EC‑80 Controller analyzes the vehicle's motion
compared to the driver's intended path and provides
Yaw Control (YC) and Roll Stability Program (RSP)
capabilities. When necessary, the system will intervene
to reduce the engine throttle, and/or apply the brakes
at one or more of the wheel ends — to help the vehicle
return to the intended direction.
Previous
Bendix®
(Bendix®
EC‑80™
EC-60™ ECU)
System Name Designations

TABLE OF CONTENTS
Page
Components . . . . . . . . . . . . . . . . . . . .
3-4
Indicator Lamps and Power-Up Sequence . . . . . 8-9
ABS Operation . . . . . . . . . . . . . . . . . . .
9-10
ATC Operation . . . . . . . . . . . . . . . . . . . 11-12
ESP ABS With Stability Control . . . . . . . . . . 12-13
Important Safety Information About
The ESP Stability System . . . . . . . . . . . . . 13-14
Troubleshooting . . . . . . . . . . . . . . . . . . . 17-62
See page 63 for the full Table of Contents

Key System Features
Key Components

ABS

“Standard”

ECU; Pressure Modulator Valves (PMVs);
Four Wheel Speed Sensors.

ATC

“Premium”

Items above, plus: Automatic Traction
Control (ATC) Valve; Option of two more
Wheel Speed Sensors and PMVs.

ESP®

All items above, plus: Yaw Rate Sensor;
Steering Angle Sensor; Load Sensor;
“Advanced”
Steer-axle ATC valve; Brake Demand
Sensor; and an Additional PMV
®

(ECU Designation Shown
on the ECU Label)

ABS [Antilock Braking]
(EC-80 ABS)

ABS plus ATC [Traction Control]
(EC-80 ATC)

ABS plus ATC plus ESP
[Yaw Control (YC) and
Roll Stability Program (RSP®)].
(EC-80 ESP)

ESP is a registered trademark of DaimlerChrysler and is used by BCVS under license.

ECU
See
Connector
Service Data
Locations
Sheet
Provided
Two

SD-13-4983

Three

SD-13-4983

Four

SD-13-4986
(This
Document)
1

GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS
TO AVOID PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:
▲ Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
Always wear personal protection equipment.
▲ Stop the engine and remove the ignition key
when working under or around the vehicle.
When working in the engine compartment,
the engine should be shut off and the ignition
key should be removed. Where circumstances
require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal
injury resulting from contact with moving,
rotating, leaking, heated or electrically-charged
components.
▲ Do not attempt to install, remove, disassemble
or assemble a component until you have read,
and thoroughly understand, the recommended
procedures. Use only the proper tools and
observe all precautions pertaining to use of those
tools.
▲ If the work is being performed on the vehicle’s
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with a
Bendix® AD-IS® air dryer system, a Bendix® DRM™
dryer reservoir module, or a Bendix® AD-9si™ air
dryer, be sure to drain the purge reservoir.
▲ F o l l o w i n g t h e v e h i c l e m a n u f a c t u r e r ’s
recommended procedures, deactivate the
electrical system in a manner that safely removes
all electrical power from the vehicle.

▲ Never exceed manufacturer’s recommended
pressures.
▲ Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove
a component or plug unless you are certain all
system pressure has been depleted.
▲ Use only genuine Bendix ® brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, fittings, etc. must be of
equivalent size, type and strength as original
equipment and be designed specifically for such
applications and systems.
▲ Components with stripped threads or damaged
parts should be replaced rather than repaired.
Do not attempt repairs requiring machining or
welding unless specifically stated and approved
by the vehicle and component manufacturer.
▲ Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
▲ For vehicles with Automatic Traction Control
(ATC), the ATC function must be disabled (ATC
indicator lamp should be ON) prior to performing
any vehicle maintenance where one or more
wheels on a drive axle are lifted off the ground
and moving.
▲ The power MUST be temporarily disconnected
from the radar sensor whenever any tests USING
A DYNAMOMETER are conducted on a Bendix®
Wingman® Advanced™-equipped vehicle.

▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the Guidelines above.

Even with the Bendix® ESP® system with the EC‑80™
Controller, the driver remains responsible for ensuring
vehicle stability during operation. The braking system
can only function within the limits of physics. The
system helps mitigate potential vehicle stability
incidents, but cannot prevent them in all cases.
Other factors such as driving too fast for road, traffic
or weather conditions, oversteering, an excessively
high vehicle Center of Gravity (CG), or poor road
conditions can cause vehicle instability that is beyond
the capability of any stability system to mitigate. In
addition, the effectiveness of Bendix ESP system
with the EC‑80 Controller can be greatly reduced on
vehicles towing multiple trailer combinations.

2

The Bendix ESP system with the EC‑80 Controller
(see page 12) may only be used on vehicles tested and
approved by Bendix engineering. The tests produce
a validated parameter data set for use by the vehicle’s
Bendix ESP EC‑80 Electronic Control Unit (ECU).
When replacing an ECU, only specific Controllers —
with the correct parameter set — may be used. See
“Obtaining a New Bendix ESP EC‑80 Controller” on
page 17 for further details.
Bendix ESP system with the EC‑80 Controller-equipped
vehicles should not be driven on high-banked roads —
such as those found on high-speed test or race tracks.
Test personnel must have the Bendix ESP system's
stability features disabled prior to operating a vehicle
on such tracks.

For vehicles with the (optional) Hill Start Aid (HSA) system
(sometimes referred to as a “Hill Start Assist”, or simply “Hill
Start”), this feature interfaces between the transmission
and the braking system. HSA helps the driver prevent
the vehicle from rolling downhill when moving up a steep
incline from a stationary position. See page 6 for more
information.

The Bendix ESP EC‑80 Controller's ESP/RSP function
utilizes the following additional components:
•

A Steer Axle Traction Control Valve (may be integral
to the service brake Relay Valve or a stand-alone
device)
Sensor
Clamping
Sleeve

YAW CONTROL (YC)
A Bendix® EC‑80™ ESP® Controller includes Yaw Control
(YC) functionality. Yaw Control has the ability to apply
brakes to individual wheel ends, as well as applying the
trailer brakes, to counteract trailer “push” that — during
certain maneuvers — could lead to a loss-of-control or
a jackknife incident. See "Yaw Stability" on page 13 for
further details.

Straight Speed
Sensors
90° Speed
Sensors

FIGURE 2 - BENDIX® WS-24™ WHEEL SPEED SENSORS

ROLL STABILITY PROGRAM (RSP)
The Bendix® Roll Stability Program (RSP), is an all-axle
ABS solution that helps decrease vehicle speed by
reducing the engine's throttle and applying all vehicle
brakes as needed, mitigating the vehicle's tendency to
roll over. RSP focuses on reducing the vehicle’s speed
below the critical roll threshold during direction-changing
maneuvers — such as driving on curved highway exit
ramps or obstacle avoidance maneuvers on dry, high
friction surfaces. See "ESP ABS with Stability Control"
on page 12 for further details.

Delivery
(Port 2)
Supply
(Port 1)

M-40X™
Modulator

Electrical
Connector
Exhaust (Port 3)

FIGURE 3 - EXAMPLE OF A BENDIX M-40X™ MODULATOR

During an RSP system intervention, the vehicle
automatically decelerates. RSP can slow the
vehicle with or without the operator applying
the brake pedal, and even when the operator is
applying the throttle.

COMPONENTS
The Bendix ESP EC‑80 Controller’s ABS function utilizes
the following components:
•

Bendix® WS-24™ Wheel Speed Sensors (four or
six, depending on the configuration), each with a
clamping sleeve. [Refer to SD-13-4860]

•

Bendix® M-40QR™ or M-40-HF™ Pressure Modulator
Valves (four, five, or six may be present) [refer to
SD-13-4958]. For legacy systems where a Bendix®
M-32™ or M-32QR™ Pressure Modulator Valve is
used, refer to SD-13-4870.

•

A dash-mounted tractor ABS Indicator Lamp

•

A service brake Relay Valve

•

A dash-mounted trailer ABS Indicator Lamp

•

An optional blink code Activation Switch

•

An optional ABS Off-road Switch

•

A dash-mounted ESP Status/Indicator Lamp (also
serves as the ATC Status/Indicator Lamp)

•

A Bendix ® SAS-60 ™ Steering Angle Sensor
(mounted to the steering column - See Figure 4)

When replacing a steering wheel, take care not to
damage the Steering Angle Sensor or interfere with
its operation, and the Steering Angle Sensor must be
recalibrated (see Troubleshooting section.)

Straight
Connector

90° Connectors

FIGURE 4 - EXAMPLES OF STEERING ANGLE SENSORS
3

•

Bendix® YAS-60™ or YAS-70X™ Yaw Rate/Lateral
Acceleration Sensors (typically mounted to a crossmember near the back of the vehicle cab). See
Figure 5.

•

Brake Demand Sensors (installed in the primary
and secondary delivery circuits)

•

A Load Sensor (typically installed in the suspension
air bag)

•

An additional Modulator Valve (Bendix® M-40QR™ or
M-40HF™ Pressure Modulator Valve) that controls
the pressure applied to the trailer brakes during a
system intervention

The Bendix ® ESP ® EC‑80™ Controller's ATC function
utilizes the following additional components:
•

A drive axle Traction Control Valve (may be integral
to the service brake relay valve or a stand-alone
device)

•

A dash-mounted ATC Status/Indicator Lamp

•

A J1939 serial communication Control Module

•

A J1939- or ECU hardware-provided Stop Lamp
Switch Input

•

An optional ATC Mud/Snow Switch (sometimes
referred to as an ATC off-road switch)
Brake Demand/
Load Sensor

Bendix® RV-3™
Pressure
Reducing Valve

Bendix® AT-3™
Traction Control
Valve

Bendix® DC-4®
Double Check
Valve

FIGURE 6 - ADDITIONAL VALVES NECESSARY FOR THE
HILL START AID FEATURE

BENDIX® ETRAC™ AUTOMATED AIR
SUSPENSION TRANSFER SYSTEM
The Bendix® eTrac™ automated air pressure transfer system
is used on 6 x 2 semi-tractors that feature Bendix® ATC
and ESP Antilock Brake Systems (ABS). This system
complements the Bendix® SMART ATC™ traction control
feature of our ABS system to provide improved traction at
low speeds (e.g. pulling away on an inclined ramp, or in
slippery conditions such as mud or snow-covered surfaces,
etc.) When active, the Bendix eTrac system vents — or
“dumps” — the air pressure of the tag axle suspension
air bags, and increases the air pressure in the drive axle
suspension air bags to a pre-determined maximum. This
action helps the drive axle to gain more traction.
See SD-13-21021 for more information about the Bendix ®
eTrac™ Automated Air Suspension Transfer System.

ECU MOUNTING
The Bendix ESP EC‑80 Controller is not protected against
moisture, and must be mounted in an environmentally
protected area.
Yaw/Lateral
Accelerator Sensors
(Two examples
shown.)

All wire harness connectors must be properly seated. The
use of secondary locks is strongly recommended.
The Bendix ESP EC‑80 Controller utilizes connectors from
the AMP MCP 2.8 product family.

HARDWARE CONFIGURATIONS
FIGURE 5 - YAW AND BRAKE DEMAND/LOAD SENSORS

The Bendix ESP EC‑80 Controller's Hill Start Aid function
utilizes the following additional components:

4

•

A Bendix® AT-3™ Traction Control Valve

•

A dash-mounted Hill Start Status/Indicator Lamp

•

A dash-mounted Enable/Disable Switch

•

A Bendix® RV-3™ Pressure Reducing Valve

•

A Bendix® DC-4® Double Check Valve

Bendix ESP EC‑80 Controllers support applications up to
six sensor/six modulator (6S/6M) installations with ATC
and drag torque control. They can also support Hill Start
functions. All 12 volt models support Power Line Carrier
(PLC). 24 volt models do not support PLC. See Figure 7
for more details.

ABS
OffRoad

ATC

Bendix ®
HSA
ATC
Blink ESP/
eTrac™
Hill Start
Mud/Snow Codes RSP Aid Feature
system*

Optional

Optional Optional

ModuRetarder
Input
Sensors
PLC lators
Relay
Voltage
(PMVs)

12/24

4/5/6

Serial
Communication

J1939

4/6

* For information about the Bendix ® eTrac™ automated air suspension transfer system, see SD-13-21021
FIGURE 7 - BENDIX® ESP® EC‑80™ CONTROLLER FEATURES

BENDIX® ESP® EC‑80™ CONTROLLERS USE
POWER LINE CARRIER (PLC)
All new towing vehicles built since March 1, 2001, have had
an in-cab trailer ABS Indicator Lamp installed.
Trailers built since March 1, 2001, transmit the status of
the trailer ABS over the power line (the blue wire of the
J560 connector) to the tractor using a Power Line Carrier
(PLC) signal. See Figures 8 and 9. Typically the signal is
broadcast by the trailer ABS Electronic Control Unit (ECU).

Suggested oscilloscope settings are AC coupling, with one
volt/div, 100 µsec/div. The signal should be measured at
the ignition power input of the Bendix EC‑80 Controller.
Note: An ABS trailer equipped with PLC, or a PLC
diagnostic tool, must be connected to the vehicle in order
to generate a PLC signal on the power line.

BENDIX ESP EC‑80 CONTROLLER INPUTS
Battery and Ignition Inputs
The Bendix ESP EC‑80 Controller operates at a nominal
supply voltage of 12 or 24 volts, depending on the ECU.
The battery input is connected through a 30 amp fuse
directly to the battery.
The ignition input is applied by the ignition switch circuit
through a 5 amp fuse.

Ground Input
FIGURE 8 - POWER LINE WITHOUT PLC SIGNAL

The Bendix ESP EC‑80 Controller supports one ground
input. See pages 52 and 53 for wiring system schematics.

ABS Indicator Lamp Ground Input
The Bendix ESP EC‑80 Controller requires a second
ground input (X1‑12) for the ABS indicator lamp. The X1
wire harness connector contains an ABS indicator lamp
interlock (X1‑15), which shorts the ABS indicator lamp
circuit (X1‑18) to ground if the connector is removed from