BENDIX SD-13-4986 User Manual

The Bendix® ESP® EC-80™ Controller

SD-13-4986

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 characterist ics of air‑braked heavy‑ and 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 inter venes when needed — using Pressure Modulator Valves (PMVs) to adjust and/or pulse the brake pressure — in order to optimize the contact bet ween the t ires and t he road surface.

2. The Bendix® Automatic T raction Control (ATC ) EC‑80 ECU provides standard ABS; improves vehicle traction during acceleration; and aid lateral stability while driving through curves. The Bendix® A TC E CU 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.

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 s ystem will intervene to reduce the engine throt tle, and/or apply the brakes at one or more of the wheel ends — to help the vehicle return to the intended direction.

™

Label Shows ECU

Designation

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

The driver is always responsible for the control and safe ope rat io n of th e vehicl e at a ll ti me s. 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.

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

Bendix

™

EC‑80

System Name

ABS “Standard”

ATC “Premium”

ESP

EC‑60™ ECU) Designations

“Advanced”

Previous (Bendix

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

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

All items above, plus: Yaw Rate Sensor; Steering Angle Sensor; Load Sensor; Steer‑axle ATC valve; Brake Demand Sensor; and an Additional PMV

Key Components

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

Key System Features

(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)

ECU

Connector

Locations

Provided

Two SD‑13‑4983

Three SD‑13‑4983

Four

)].

See

Service Data

Sheet

SD‑13‑4986

(This

Document)

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 sho uld be shut off and the ig nition key should be removed. Where circumst ances 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 att empt to install, remove, dis assemble

or assemb le a component until you have re ad, and thoroughly understand, the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.

▲ If the wor k is being per formed on th e vehicle’s

air brake system, or any auxiliary pressurized air systems, make ce rta in to drain th e air pressur e from all rese rvoirs before be ginning ANY work on the vehicle. I f th e vehicle i s equip ped wi th a Bendix® AD-IS® air dryer system, a Bendix® DRM™ dryer re se rvoir modul e, o r a B en di x® AD-9si™ air dryer, be sure to drain the purge reservoir.

▲ Following the vehicle manufacturer’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 compone nt or plug unless you ar e certai n all system pressure has been depleted.

▲ Use only genuine Bendix

parts, components and kits. Replacement

hardware, tubing, hose,  ttings, etc. must be of

equivalent size, type and strength as original

equipment and be designed speci cally for such

applications and systems.

▲ Component s with st rippe d threads o r damaged

part s should be replaced ra ther than repaired. Do not attempt repairs requiring machining or

welding unless speci cally stated and approved

by the vehicle and component manufacturer.

▲ Prior to retur ning the vehicle to ser vice, make

certain all components and systems are restored to their proper operating condition.

▲ For vehicles with Automatic Traction Control

(ATC), the ATC function m ust be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a d rive axle ar e lifted of f the groun d and moving.

▲ The power MUST be t emporarily disco nnected

from the radar sensor whenever any tests USING A DYNAMOMETER are conducted on a Bendix Wingman® Advanced™-equipped vehicle.

brand replacement

▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,

in conjunction with the Gu ideli nes 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, trafc

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.

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 specic Controllers —

with the correct parameter set — may be used. See

“Obtaining a N ew Bendix ES P EC‑ 80 C ontroller ” on page 17 for further details.

Bendix ESP system with the EC-80 Controller-equipped

ve hi c les should not be dr i v e n on hi g h -ba n k e d ro a d s —

such as those found on high-speed test or race tracks. Test per sonnel must have the Be ndix 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 interfac es between the transmis sion and the braking system. HSA helps the driver prevent the vehicle from rolling downhill w hen m oving up a steep incline from a stationar y position. See page 6 for more

information.

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 “pus h” that — during cert ain maneuvers — could lead to a loss‑ of‑control or a jackknife incident. See " Yaw Stability" on page 13 for

further details.

ROLL STABILITY PROGRAM (RSP)

The Bendix 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 reducin g the vehicle’s speed below the critical ro ll thre sho ld dur in g direc ti on‑changing maneuvers — such as driving on curved highway exit ramps or obstacle avoidance maneuvers on dry, high friction sur faces. See " ESP ABS with Stabilit y Control"

on page 12 for further details.

Roll Stability Program (RSP), is an all‑a xle

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

• A Steer Axle T raction Control V alve (may be integral to the service brake Relay Valve or a stand‑alone device)

Sensor

Clamping

Sleeve

Straight Speed

90° Speed

Sensors

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

Delivery

(Port 2)

™

M-40X

Modulator

Exhaust (Port 3)

Sensors

Supply

(Port 1)

Electrical

Connector

During an RSP syste m intervent ion, the vehicle automatically decelerates. RSP can slow the vehicle with or without the operator applying the brake p edal, and even when the o perator 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 conguration), each with a

clamping sleeve. [Refer to SD-13-4860]

• Bendix® M‑40QR™ or M‑40‑HF™ Pressure Modulator

Valves (four, ve, 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

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

• 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

FIGURE 4 - EXAMPLES OF STEERING ANGLE SENSORS

90° Connectors

• Bendix® YAS‑60™ or YAS‑70X™ Yaw Rate/Lateral Acceleration Sensors (typically mounted to a cross‑ member 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 V alve (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

FIGURE 6 - ADDITIONAL VALVES NECESSARY FOR THE

HILL START AID FEATURE

™

Bendix® AT-3

Traction Control

Valve

™

Bendix Double Check

Valve

DC-4

BENDIX® ETRAC™ AUTOMA TED AIR SUSPENSION TRANSFER SYSTEM

The Bendix® eTrac™ automated air pressure transfer system is used on 6 x 2 semi‑trac tors that feature Bendix® ATC and ESP Antilock Brake Systems (ABS). This system complements the Bendix® S MART AT C™ 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 susp ension air bags, and increases the air pressure in t he drive a xle 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.

Yaw/Lateral

Accelerator Sensors

(Two examples

shown.)

FIGURE 5 - YAW AND BRAKE DEMAND/LOAD SENSORS

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

• 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

ECU MOUNTING

The Bendix ESP EC‑80 Controller is not protected against moisture, and must be mounted in an environmentally protected area.

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

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 suppor t Power Line Carr ie r (PLC). 24 volt models do not support PLC. See Figure 7

for more details.

ABS

Off-

Road

ATC

Mud/Snow

Blink

Codes

ESP/

RSP

HSA

Hill Start

Aid Feature

Bendix

eTrac

system*

Optional Optional Optional 12/24 4/5/6 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 Marc h 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).

™

Voltage

Input

PLC

Modu-

lators

(PMVs)

Retarder

Relay

Sensors

Serial

Communication

J1939

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 oper ates at a nominal supply voltage of 12 or 24 volts, depending on the ECU. The battery input is connected through a 3 0 amp fuse directly to the battery.

The ignition input is applied by the ignit ion switch circuit through a 5 amp fuse.

FIGURE 8 - POWER LINE WITHOUT PLC SIGNAL

FIGURE 9 - POWER LINE WITH PLC SIGNAL

The application of PLC technology fo r the heavy vehicle industry in North America is known as “PLC4Trucks.”

The Bendix® ESP® EC‑ 80™ Controller supports PLC communications in accordance with SAE J2497.

PLC SIGNAL

An oscillosc ope can be used to measure or identif y the presence of a PLC signal on the power line. The PLC signal is an amplitude and frequency‑modulated signal.

Depending on the ltering and load on the power line,

the PLC signal amplitude can range from 5.0 mVp‑p to

7.05 Vp‑p.

Ground Input

The Bendix ESP EC‑ 80 Controller supp orts one gr ound 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 co nnector contains an AB S indicator lamp interlock (X1‑15), which shorts the ABS indicator lamp circuit (X1‑18) to ground if the connector is removed from the ECU.

Bendix® WS-24™ Wheel Speed Sensors

Wheel speed data is provided to the B endix ESP EC‑ 8 0 Controller from the Bendix® WS‑24™ wheel speed sensor (see Figure 2). Vehic les have an exciter ring (or “tone ring”) as part of the wheel assembly. As the wheel turns, the teeth of the exciter ring pass the whee l speed sensor, generating an AC signal. The Bendix ESP EC‑80 Controller receives the AC signal, which varies in voltage and frequency as the wheel speed changes.

Vehicle axle configurations determine the number of Bendix WS‑24 wheel speed se nsors that must be used. A vehicle with a single rear axle requires four wheel speed sensors. Vehicles with two rear axles can utilize six wheel speed sensors for optimal performance.

Diagnostic Blink Code Switch

A momentary switch that grounds the ABS Indicator Lamp output is used to place the ECU into the diagnostic blink code mode and is typically located on the vehicle’s dash panel.

Optional ABS Off-Road Switch and Indicator Lamp Operation

Vehicle operators use an optional dash‑mounted switch to place the Bendix® ESP® EC‑ 8 0™ Controller into the ABS off‑road m ode. See "Optional A BS Off- Road Mode" on page 10 for further details. In some c ases, ECUs may also be put into the ABS off‑road mode by one of the other vehicle control module s, using a J193 9 message to the Bendix ESP EC‑80 Controller.

(If you need to know if a specic Bendix ESP EC‑80

Controller uses a J1939 message to operate the lamp, contact the Bendix Tech Team. E‑mail the Tech Team at ABS@bendix.com (be sure to specify the ECU par t number), or call 1‑800‑AIR‑BRAKE (1‑800‑245‑2725).

The ABS off-road mode should not be used on normal, paved road surfaces because vehicle stability and steerability may be adversely affected. When the ECU is placed in the ABS off-road mode,

the ABS Indicator Lamp will ash constantly (at a

rate of onc e per 2 .5 secon ds) to notif y th e vehicle operator that the off-road mode is active.

Optional ATC Mud/Snow (Off-Road) Switch and Indicator Lamp Operation (also see page 8.)

The Bendix ESP system uses a dash‑mounted switch for the operator to place the ECU into the ATC Mud/Snow mode.

Optional Hill Start/Hill Start Assist Feature Switch and Lamp Operation (see also page 8.)

ESP Controllers use a dash‑mounted switch for the operator to place the ECU into the hill star t mode. This feature interfaces between the transmission and the braking system to help the driver prevent the vehicle from rolling downhill when moving up a steep incline fro m a stationary position.

With Hill Start Aid Feature option you lose the ABS off-road function and the retarder relay output.

When the ECU is placed in the Hill Start Aid (HSA) feature

mode, the HSA Indicator Lamp will ash constantly (at a

rate of once per 2.5 seconds) to notify the vehicle operator that the HSA mode is active. The ECU receives J1939 messages from the t ransmissi on to engage the H S/HSA components. When engaged, the system applies 44 psi to the rear brakes for three (3) seconds then releases. This function is totally controlled by the automatic transmission.

Stop Lamp Switch (SLS)

The Bendix ESP EC‑ 80 Controller monitors the vehic le stop lamp status. Certain vehicle functions, such as ATC and All‑Wheel Drive (AWD), use the status of the stop lamp to determine when the driver makes a brake application. This c an be provided to the ECU via J1939 communications, or hardware input.

Brake Demand Sensors

The brake demand sensors provide the Controller with an indication of driver‑applied brake pressure. One is installed in the primary air brake circuit, and another is installed in the secondary air brake circuit.

Load Sensor

The load sensor provides the Controller with an indication of the vehicle load. It is typic ally installed in one of the suspension air bags.

Bendix® SAS-70X™ Steering Angle Sensor

Bendix® brand Steering Angle Sensors (SAS) are used to report the steering wheel position to the Controller, utilizing a dedicated serial communications link that is shared with the Y a w Rat e Sensor. The Controller supplies the power and ground inputs to the Bendix® SAS‑70X™ sensor.

The Bendix SAS‑70X sensor is available with two different styles of wire harness connectors. (See Figure 4.)

Bendix® YAS-60™ or Y AS-70X™ Yaw Rate/Lateral Acceleration Sensors

Bendix® brand yaw rate/lateral acceler ation sensors are used to provide the Controller an indication of vehicle lateral acceleration an d rotati on around t he ver ti c al ax is. This information is provided to t he Controller, utilizing a dedicated serial c ommunications link that is sha red with the Bendix® SAS‑60™ sensor. The Controller supplies the power and ground inputs to the yaw rate sensor.

BENDIX® ESP® EC-80™ CONTROLLER OUTPUTS

Bendix® M-40QR™ and M-40HF™ Pressure Modulator Valves (PMVs)

The Bendix ESP EC‑80 Controller operates Bendix® M‑40QR™ and M‑40HF™ Pressure Modulator Valves (PMVs) to modify the dr iver‑applied air pressure to the servic e brakes during ABS, ATC, RSP or YC activation (see pages 9-13). The PMV is an electropneumatic 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 hold solenoid is normally open and the release solenoid is normally closed, such that the PMV nominally allows air to

ow through. This design allows for air delivery to brake

chambers in the event of electrical trouble.

The Bendix® ESP® EC‑ 80™ Controller also utilizes an additional Pressure Modulator Valve (PMV) for control of the trailer service brakes during stability interventions.

Traction Control Valve (TCV)

Bendix ESP EC‑80 Controllers use two TCVs, one on the steer axle and one on the dr i ve a x l e. The TCV may be a separate valve or integrated into the rear axle relay valve.

The Controller will activate the drive axle TCV during differential braking ATC events.

During stabilit y interventions, the Controller will act ivate both the steer axle and drive axle TCVs as required.

Stop Lamp Output

The Controller provides an output to control a relay that illuminates the vehicle stop lamps during stability interventions. This information is also available using the J1939 serial communications link.

ABS Indicator Lamp Control with Optional Diagnostic Blink Code Switch

The Bendix ESP EC‑80 Controller has internal circuitry to control the ABS Indicator Lamp on the dash panel.

The ABS Lamp Illuminates:

1. During power up (e.g. when the vehicle is started) for approximately three (3) seconds and turns off after the self‑test is completed, providing no Diagnostic Trouble Codes (DTCs) are present on the ECU;

2. When full ABS operation is not available due to the presence of a DTC on the ECU;

3. If the ECU is unplugged or has no power;

4. When the ECU is placed into the ABS off‑road

mode (the lamp ashes steadily at a rate of once per

2.5 sec.); or

5. To display blink codes for diagnostic purposes after the external diagnostic switch is activated.

The Bendix ESP EC‑80 Controller may communicate with other vehicle control modules to operate the ABS Indicator Lamp using serial communications. (If you need to know if this Bendix ESP EC‑ 80 Controll er uses serial communications to operate the lamp; e‑mail ABS@ bendix.com, (be sure to specify the ECU part number), or call 1‑800‑AIR‑BRAKE/1‑800‑247‑2725 and speak to the Bendix Tech Team.)

Indicator Lamp Control Using Serial Communications Links

As mentioned above, depending on the vehicle manufacturer, the dash indicator lamps (ABS, ATC, ESP, and trailer ABS) may be controlled using serial communications links. In the se cases, the Bendix ESP EC‑80 Controller will send a serial communications message over the J1939 link, indicating the required status of the lamp(s). Another vehicle contro l module receives the message and controls the indicator lamp(s).

Dynamometer Mode Indicator Lamp Operation

When the Bendix ESP EC‑ 80 Controller is put into the Dynamometer mode for testing purposes, the ATC Indicator Lamp will be illuminated.

Retarder Relay Disable Output

The retarder relay disable output may be used to control a

retarder disable relay. When congured to use this output,

the ECU will energize the retarder disable relay and inhibit the use of the retarder as needed.

If the ECU is congured for the Hill Start/ Hill Start Assist

feature (HS/HSA), the retarder relay output pin is used to control the Hill St art status lamp. As a result, the vehic l e loses the retarder relay function when it has the Hill Start feature.

SAE J1939 Serial Communications

A Controller Area Network (CAN) data link (SAE J1939 ) is provided for communication. This link is used for various functions, such as:

• Diagnostic purposes.

• To disable retarding devices during ABS operation.

• To request that the torque converter disable lock‑up during ABS operation

• To share information such as wheel speed and ECU status with other vehicle control modules.

Bendix ESP EC‑80 Controllers utilize the J1939 data link for:

• ATC and drag torque control functions.

• Vehicle stability functions.

Trailer ABS Indicator Lamp Control

The Bendix ESP EC‑80 Controller will activate a trailer ABS Indicator Lamp (located on the dash panel) that indicates the status of the trailer ABS unit on one, or more trailers, or dollies that are equipped with PLC functionality. T ypically , the Bendix ESP EC‑80 Controller directly controls the trailer ABS Indicator Lamp based on the information it receives from the trailer ABS, via PLC.

Alternatively, some vehicles require the Bendix ESP EC‑80 Controller to activate the trailer A BS Indicator Lamp by communicating with other vehicle Controllers using serial communications.

(If you need to know if this Bendix ESP EC‑ 80 Controller uses a serial communications message to operate the lamp, e‑mail ABS@bendix.com (be sure to specify the ECU part number), or call 1‑800‑AIR‑BRAKE (1‑800‑245‑2725) and speak to the Bendix Tech Team.)

Interaxle Differential Lock Control (AWD Transfer Case)

Bendix ESP EC‑ 80 Controllers c an control the intera xle differential lock (AWD transfer case) . This is recommended

on AWD vehicles, but the ECU must be specially congured

to provide this feature. E‑mail ABS@bendix.com for more details.

INDICATOR LAMPS AND POWER-UP

ATC

SEQUENCE

NOTICE: The vehicle operator should Verif y the proper

operation of all installed indicator lamps (ABS, ATC/ESP, and trailer ABS) when applying ignition power and during vehicle operation. See Figure 10.

Lamps that do not illuminate as expected when ignitio n power is applied, or remain illuminated, indicate the need for maintenance.

Dash Lamp Behavior for the

ABS

Bendix® ESP® EC-80™ Controller

Mode

Ignition on ‑ start up

[trailer with Power Line

Carrier (PLC)]

3 seconds after ignition

At Vehicle Startup

[with no Diagnostic

Trouble Codes (DTCs)]

ABS

Off-Road

Mode

Vehicles with Hill Start Aid (HSA):

Special Mode Operation

Deep

Mud/

Snow/

Mode

During an Automatic Traction Control (ATC) Event Flashes quickly • Reduces wheel slip during acceleration at low speeds

During Dynamometer Mode

Normal

During an ATC

Event

‑— OR, depending on vehicle options (a vehicle can have either ABS off‑road or HSA) —

During HSA Mode

(“Hill Start” / “Hill Start Assist”)

Normal OFF

During an ATC/ESP

Event

During an ESP Event Flashes quickly •

ABS

Lamp

ON for

three (3)

seconds*

Lamp OFF* Lamp OFF* Lamp OFF**

Lamp ashes

slowly (every 2.5

seconds)

OFF Flashes quickly

ATC/ESP Lamp

ON for 2.5

seconds*

Lamp OFF

Flashes quickly

During HSA Event Lamp OFF

HSA Manually Disabled

Flashes slowly

(every 2.5

seconds)

Lamp ON

(ATC

Disabled)

TRLR

ABS Lamp

seconds**

• Uses dash switch

• Not for rm road surfaces

• Allows more wheel lock‑up (less ABS intervention)

• Mode only applies under 25 mph (Over 25 mph, the system reverts to

• Disables ATC monitoring functions

• When not in Dynamometer Mode, an illuminated lamp indicates an ATC DTC is present

HSA

Trailer

ON for

three (3)

full ABS ‑ including ATC/ESP — and upon exiting off‑road mode, the ATC lamp extinguishes.)

• Uses dash switch

• Increases allowable wheel slip during ATC interventions

• Not for rm road surfaces

System intervenes to reduce the risk of rollovers, loss‑of‑control, etc.

HSA

Lamp

ON for

three (3)

seconds*

Lamp

OFF*

Flashes

slowly

Comments

If any of the described lamp behaviors

do not occur — or if the lamp remains on during operation — have the vehicle

serviced by a qualied mechanic as

soon as possible to restore full system functionality.

Some vehicle manufacturers may

illuminate the trailer ABS indicator lamp at power‑up regardless of whether a PLC signal is detected from the trailer or not. Consult the vehicle manufacturer’s documentation for more details.

• The HSA lamp is illuminated only at power‑ up, or if an HSA DTC is present

0.5 2.0 2.5 3.0 (sec.)1.5

Power

Application

ATC/ESP System

Status Indicator

at Start-Up

ATC/ESP

enabled

No ESP

or ATC

ABS System

Status Indicators

at Start-Up

Powered Vehicle ABS

Indicator Lamp

Trailer ABS

Indicator Lamp

(PLC Detected)**

Trailer ABS

Indicator Lamp**

(PLC Not Detected)

ON OFF

FIGURE 10 - BENDIX® ESP® EC‑80™ CONTROLLER INDICATOR LAMP BEHAVIOR 8

ON OFF

0.5 2.0 2.5 3.0 (sec.)1.5

Power

Application

ABS Indicator Lamp Operation (Bulb Check)

The Bendix® ESP® EC‑80™ Controller will illuminate the ABS Indicator Lamp for approximately three seconds when ignition power is applied, after which the lamp will extinguish if no Diagnostic Trouble Codes (DTCs) are detected.

The Controller will illuminate the ABS Indicator Lamp whenever full ABS operation is not available due to a DTC. In most cases, partial ABS is still available.

ATC/ESP Status/Indicator Lamp Operation

The Bendix ESP EC‑80 Controller will illuminate the A TC/ ESP lamp for approximately 2.5 seconds when i gnition power is applied, after which t he lamp will extinguish if no DTCs are detected. The Controller will continuously illuminate the AT C/ESP Indicator Lamp whenever ESP or ATC is disabled due to a DTC.

During an ESP or ATC intervention, the lamp will ash

rapidly (2.5 times per second). When the C ontroller is placed in the ATC Mud/Snow (off‑ road) mode, the lamp

will ash slowly at a rate of once every 2.5 seconds.

Trailer ABS Indicator Lamp Operation

The Controller will control the Trailer ABS Indicator Lamp when a PLC signal (SAE J2497) from a trailer ABS ECU is detected.

Hill Start Assist (HSA) Indicator Lamp Operation

Vehicles with HSA enabled, will illuminate the HSA Indicator Lamp when ignition power is applied. The lamp will extinguish if there are no issues with the HSA system.

This test is performed only when the vehicle is stationary (if the vehicle moves, the Chuff Test will not be performed).

The Bendix ESP EC‑80 Controller will per form a PMV Chuff Test on all installed modulators in the following order:

• Steer Axle Right PMV;

• Steer Axle Left PMV;

• Drive Axle Right PMV;

• Drive Axle Left PMV;

• Additional Axle Right PMV;

• Additional Axle Left PMV; then

• Drive Axle TCV The pattern will then repeat itself. See Figure 11. Vehicles with a Bendix ESP EC‑80 Controller — following

the completion of the second round of PMV & TCV Chuff

Tests — the Controller (if congured to do so) will perform

a test to cross‑ check the trailer PMV o peration with the vehicle stop lamps. If the trailer PMV c irc uit i s mis‑wired (including the steer axle TCV), the PMV will exhaust a large amount of air, or none at all.

NOTICE: If there are any active DTCs, the stop lamp cross‑check portion of the Chuff Test will not be carried out until all DTCs are fully diagnosed and the corresp onding repairs are succes sfully conduc ted. The ESP/ATC dash indicator will also illuminate when there are ac tive ABS, ATC or ESP DTCs.

The ECU will not perform the PMV Chuff T est when wheel speed sensors show that the vehicle is in motion.

Pressure Modulator Valve (PMV) and Traction Control Valve (TCV) Chuff Test

Right Steer

Driver

Left Steer

FIGURE 11 - VEHICLE ORIENTATION (TYPICAL)

After the performance of the conguration test, the Bendix

ESP EC‑80 Controller will perform a Bendix‑patented PMV and TCV Chuff Test. The Chuff Te st is an elect ric al and pneumatic PMV test that can assist maintenance personnel in verifying proper PMV wiring and installation.

When ignition power is applied, eac h m odulator so le noi d

is briey energized. If the air system is fully charged and

the servic e brake pedal is depres sed during i gnition, the modulator creates a single, sharp audible “chuf f” of air pressure. The modulators are energized in a certain pattern: right front; left front; right rear; then left rear.

Right Drive

Left Drive

Right

Additional

Left

Additional

ABS OPERATION

Bendix® ABS uses wheel speed s ensors, ABS pres sure modulator valves, and an ECU to control either four or six wheels of a vehicle. The Bendix ESP EC‑ 80 Controlle r monitors individual wheel tur ning motion during brak ing, and adjusts or modulates the brake pressure at the wheel end. When excessive wheel slip — or wheel lock‑up — is detected, the Bendix ESP EC‑ 80 Controller will act ivate the pressure modulator valves to automatically reduce the brake pressure at one or more of the wheel ends. By these actions, the A BS system helps to maintain the vehicle's lateral stability and steerability during heavy brake applications and during braking on slippery surfaces.

Steer Axle Control

Although both wheels of the steer axle have their own wheel speed sensor and pres sure modulator valve, the Bendix ESP EC‑ 80 Controller blends the applied braking force between the two steering axle brakes. This Bendix patented brake application control, called Modified Individual Regulation (MIR), is designed to help reduce steering wheel pull during an ABS event on road surfaces with poor tracti on, or areas of poor tracti on (e.g. asphalt road surfaces with patches of ice).

Single Drive Axle Control (4x2 Vehicle)

For vehicles with a single rear drive axle (4x2) , the brakes are operated independently by the Bendix® ESP® EC‑80™ Controller, based on the individual wheel behavior.

Dual Drive Axle Control (4S/4M Conguration)

For vehicles with dual drive axles (6x4) using a 4S/4M

conguration, one ABS modulator controls both of the

right‑side rear whe els; the other modulator c ontrols both of the left‑side r ear wheels. Both wheels on each side receive equal brake pressure during an A BS stop. The rear wheel speed sensors must b e installed on the axle with the lightest load.

Dual Rear Axle Control (6S/6M Conguration)

For vehicles with dual rear axles (6x4, 6x2) using a 6S/6M

conguration, the rear wheels are controlled independently.

Therefore, brake application pressure at each wheel is adjusted according to the individual wheel behavior on the road surface.

6x2 Vehicles with 6S/5M Conguration

6x2 vehicles can utilize a 6S/5M conguration, with the

additional axle (a non‑driven rear axle) having two sensors, but only one Pressure Modulator Valve (PMV). In this case, the PMV controls both wheels on the additional axle. The additional axle wheels would receive equal brake pressure, based on the wheel that is currently experiencing the most wheel slip.

Normal Braking

During normal braking, brake pressure is delivered through the ABS PMV and into the brake chamber. If the ECU does not detect excessive wheel slip, it will not activate ABS control, and normal vehicle service braking is applied.

Retarder Brake System Control

On surfac es with low trac tion, applic ation of the retar der can lead to high levels of wheel slip at the drive axle wheels, which can adversely affect vehicle stability.

T o prevent this, the Bendix ESP EC‑80 Controller switches off the retarder as soon as a lock‑up is detected at one (or more) of the drive axle wheels.

When the ECU is placed in the A BS off‑road mode (on vehicles equipped with this optional feature), it will switch off the retarder only w hen ABS is active on a steer a xle wheel and a drive axle wheel.

Optional ABS Off-Road Mode

On some road conditi ons, particularly when the drivin g surface is s oft, the stopping distance with conventional ABS may be longer than witho ut ABS. This can occur when a locked wheel on soft ground or loose gravel plows up the road surface in front of the tire, changing the rolling friction value. Alt hough vehicle stopping dist ance with a locked wheel (in the absence of ABS) may be shorter than

corresponding stopping distanc e with conventional ABS control, vehicle steerability and stability would be reduced.

Bendix ESP EC‑80 Controllers have an optional dash

switch that initiates a modied ABS control mode (known

as "off‑road A BS") that more effectively ac commodates these soft road c onditions to shorten stopping distanc e while maintaining optimal vehicle steerability and stability.

Note: Off‑road mode is not available if the vehicle is equipped with Hill Start / Hill Start Assist (HS or HSA).

The ABS off-road mode should not be used on normal, paved road surfaces because vehicle stability and steerability may be reduced. The ABS

Indicator Lamp will ash slowly to indicate to the

driver that the ABS off-road mode is engaged.

When ABS off-road mode is engaged, stability functions are disabled at speeds below approximately 25 mph/40 kph. The A TC/ESP dash lamp will illuminate to indicat e to the driver that t he stability syst em is disabled.

The vehicle manufacturer should provide the optional ABS off‑road function only for vehicles that operate on unpaved surfaces — or that are used in off‑road applications — and is responsible for ensuring that vehicles equipped with the ABS off‑road function meet all FMVSS‑121 requirements and have adequate operator indicators and instructions.

The vehicle operator activates the off‑road function with a

switch on the dash panel. A ashing ABS Indicator Lamp

indicates to the driver that the A BS off‑road function is engaged. To exit the ABS of f‑road mode, depress and release the switch. A new ignition cycle w ill also cause the ECU to exit the ABS off‑road mode.

All-Wheel Drive (AWD) Vehicles

AWD vehicles with an engaged interaxle differential (steer axle to rear axle) / AWD transfer case, may have negative effects on ABS performance. Optimum ABS performance is achieved when the lockable differentials are disengaged, allowing individual wheel control.

Bendix ESP EC‑80 Controllers can be programmed

specically for this conguration to control the differential

lock/unlock solenoid in the AWD transfer case. When programmed to do so, the ECU will disengage the locked interaxle/AWD transfer case during an ABS event and reengage it once the ABS event has ended.

ATC OPERATION

ATC Functional Overview

Just as ABS improves vehicle stabilit y during braking, Automatic T raction Control (A TC ) improves vehicle stability and traction during vehicle acceleration. The Bendix® ESP® EC‑ 80™ Controller's ATC function uses the same wheel speed information and modulator control as the ABS function. The Bendix ESP EC‑80 Controller detects excessive drive wheel speed; compares the speed to the front, non‑driven wheels; and reacts to help bring the wheel

spin under control. The Controller can be congured to use

engine torque limiting and/or differential braking to control wheel spin. For optimal AT C performance, both methods are recommended.

ATC/ESP Lamp Output/ATC Mud/Snow Switch Input

Bendix ESP EC‑80 Controllers operate the AT C/ESP dash lamp as follows.

The ATC/ESP dash lamp illuminates:

1. During power up (e.g. when the vehicle is started) for approximately 2.5 seconds and turns off after the self test is completed, providing no Diagnostic Trouble Codes (DTCs) are present.

2. When ESP or ATC is disabled for any reason.

3. During an ESP or ATC event (the lamp will ash rapidly

at a rate of 2.5 times per second).

4. When the ECU is placed in the ATC off‑road mode

(the lamp will ash steadily at a rate of once every 2.5 seconds). This noties the vehicle operator that the

ATC Mud/Snow mode is active.

5. When the ECU is placed in the ABS off‑road mode. When in this mode, ESP will be disabled below 25 mph and its inactive status will be indicated by a steadily illuminated A TC/ESP lamp.

Differential Braking

Differential br aking within ATC is automatically activated when drive wheel(s) on one side of the vehicle are spinning excessively. This typically occurs on road sur faces with patches of ice. The tract ion system will then lightly apply the brake to the drive wheel(s) that are spinning excessively. The vehicle differential will then drive the wheels on the other side of the vehicle.

Differential braking (as part of A TC functionality) is available at vehicle speeds up to 25 mph/40 kph.

Disabling ATC Differential Braking

ATC differential braking is disabled under the following conditions:

1. During power up (e.g. when the vehicle is started), until the ECU detects a service brake application.

2. If the ECU receives a J1939 message indicating that the vehicle is parked.

3. When the dynamometer test mode is active. The Dynamometer test mode is entered using the diagnostic Blink Code Switch or by using a diagnostic tool (such as Bendix® ACom® Diagnostics).

4. In response to a serial communications request from a diagnostic tool.

5. If ATC Differential Braking function is activated for a long time period to avoid overheating of the brakes. It would take approximately three (3) continuous minutes of activation for the time‑out to occur. Once timed‑out, approximately two (2) minutes of "cool off" time would be required before A TC Dif ferential Braking can be used again.

6. When certain DTC conditions are detected.

Traction Control with Engine Torque Limiting

The Bendix ESP EC‑ 80 Controller uses Engine Torque Limiting to control drive ‑ axl e wheel slip. This is c ommu ‑ nicated to the engine contro l module (using J19 39), and is available at all vehicle speeds.

Bendix® SMART ATC™ System

The Bendix ESP EC‑80 Controller has an additional feature known as the Bendix® SMART ATC™ system. This system monitors the accelerator pedal position (using J1939) to help provide optimum traction and vehicle stability. By determining the driver’s throttle input and adapting the target slip of the drive wheels to the dr iving s ituation, th e Bendix SMART ATC system allows higher wheel slip when the accelerator pedal is applied above a preset level.

The wheel slip allowed by the Bendix SMART AT C system is decreased when dri ving through a cur ve for improved stability.

Disabling ATC Engine Control and the Bendix SMART A TC System

A TC Engine Control and the Bendix SMART AT C system will be disabled under the following conditions:

1. In response to a serial communications request from an off‑board tool;

2. At power‑up until the ECU detects a service brake application;

3. If the ECU receives a J1939 message indicating that the vehicle is parked;

4. If the dynamometer test mode is active. This may be accomplished via an off‑board tool or the diagnostic Blink Code Switch; or

5. When certain DTC conditions are detected.

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‑8 0™ Controller has an optional c o ntro l m od e to permit this desired performance.

The vehicle operator can activate the Mud/Snow function with a switch on the dash panel. Alter nately, a J1939 message may be used to place the vehicl e in this mo de.

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. T o exit the A TC Mud/Snow mode, depress and release the

ATC Mud/Snow switch.

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 Y aw Control (YC) functions. During operation, the Bendix ESP EC‑80 Controller constantly compares performance models to the vehicle’s

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 iner t ia. This c on dition i s address ed by increasing the engine torque to overcome the inertia.

Drag torque control increases vehicle stabilit y on low‑ traction road sur faces during down‑shifting or retarder braking.

actual movement, using wheel speed sensor s; 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 criti cal threshold values are approached, the system will intervene to assist the driver.

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.

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 and selectively applies brakes to reduce the tendency to jackknife.

Y aw Control system reduces engine throttle

FIGURE 12 - RSP EXAMPLE

FIGURE 13 - YAW CONTROL EXAMPLE

Bendix® Roll Stability Program (RSP®)

Bendix RSP — an element of the overall Bendix® ESP® system with the EC‑8 0™ Controller — addresses r ollover conditions. In the c ase of a potential roll event, the ECU will override the throttle and quickly apply brake pressure at all wheel ends to slow the vehicle co mbination. The level of braking application during an RS P event will be proportional to roll risk. See Figure 12.

Yaw Stability

Y aw stability counteracts the tendency of a vehicle to spin about its vertic al axis. Dur ing operation — if t he frict ion

between the road surface and the tires is not sufcient

to oppose lateral (side) forces — one or more of the tires can slide, causing the truck/tractor to spin. These events are referred to as either an "under‑steer" situation (where there is a lack of vehicle response to steering input due to tire slide on the steer axle), or an "over‑steer" (where the tractor's rear end slides out due to tire slide on the rear axle) situation. Generally, shorter wheelbase vehicles (tractors, for instance) have less natural yaw stability, while longer wheelbase vehicles (straight trucks, for instance) have

greater natural yaw stability. Factors that inuence yaw

stability are: wheelbase, suspension, steering g eometry, weight distribution front to rear, and vehicle track width.

Yaw Control

Yaw control responds to a wide range of low‑ to high‑ friction sur face scenarios including rollover, jackknife and loss‑of‑control. It is the recommended system for all power vehicles and especially cr itical for trac tors pulling trailers. In the case of vehic le slide (over‑steer or under‑ steer situations), the system will reduce the throttle and then brake one or more of the “four corners” of the vehicle (in addition to potentially applying the trailer brakes) , thus applying a counter‑force to better align the vehicle with an appropriate path of travel.

For example, in an over ‑steer situation, the system applies the “outside” front brake; while in an under‑steer condition, the “inside” rear brake is applied. (See Figure 13)

IMPORTANT SAFETY INFORMATION ABOUT THE BENDIX® ESP® SYSTEM

The Bendix ESP EC-80 Controller may reduce the vehicle speed automatically.

The Bendix® ESP® system can make the vehicle decelerate automatically and can slow the vehicle w ith or wit h o ut the operator

applying the brake — and even when the

throttle is being applied.

T o minimize une xpected deceleration and reduce the risk of a collision, the operator must:

• Avoid aggressive driving maneuvers, such as sharp turns or abrupt lane changes at high speeds, which might trigger the stability system; and

• Always operate the vehicle safely, drive defensively , anticipate obstacles and pay attention to road,

weather and trafc conditions. Bendix ABS, ATC

and ESP systems are no substitute for prudent, careful driving.

Towing Doubles Or Triples May Reduce The Effectiveness Of Stability Systems

The Bendix ESP syst em wi t h th e EC-80 Con t roll er i s designed and optimized for trucks and for tractors that tow single trailers. If a tractor equipped with Bendix ESP is used to powe r multiple trail er combination s (known as “doubl es” or “trip les”) the eff ectiveness of the Bendi x ESP system may be greatly r educed. Extremely careful driving is always required when towing doubles or triples. Excessive speed and

aggres s i v e ma n e uv e r s — such as sha r p tu r ns , su d den steering inputs, or abrupt lane changes — should be

avoided.

Limitations Of Stability Systems

The effectiveness of the Bendix ESP system with the EC‑80 Controller may be greatly reduced if:

• The load shifts due to improper retention, accident damage, or the inherently mobile nature of some loads (for example, hanging meat, live animals or partially laden tankers),

• The vehicle has an unusually high — or off‑set — center of gravity (CG),

• One side of the vehicle drops off the pavement at an angle that is too large to be counteracted by a reduction in speed,

• The vehicle is used to haul double or triple trailer combinations,

• If very rapid steering changes are attempted at high speeds,

• There are mechanical problems with suspension leveling of the tractor or trailer resulting in uneven loads,

• The vehicle is maneuvering on a high banked road creating either additional side forces due to the weight (mass) of the vehicle, or a deviation between expected & actual yaw rates,

• Gusty winds are strong enough to cause signicant

side forces on the vehicle and any towed vehicles.

To Maximize The Effectiveness Of The Bendix®

System with the EC-80™ Controller:

ESP

• Loads must be properly secured at all times.

• Drivers need to exercise extreme caution at all times, plus avoid sharp turns, sudden steering adjustments or abrupt lane changes at high speeds, particularly if:

› the vehicle hauls loads that could shift; › the vehicle or load has a high or off‑set center of

gravity (CG) when loaded; or

› the vehicle tows doubles or triples.

Truck Chassis Modications

If the vehicle’s chassis components are altered (for example, a wheel base extension or reduction; tag axle addition or rem oval; a major body change suc h as conversion of a tractor into a truck; or an axle, suspension,

or steering system component modication) the Bendix

ESP

system must be disabled. Have a qualied mechanic

replace the Bendix ESP EC‑80 Co ntr o lle r w it h a B e ndi x®

ESP

ATC EC‑80™ Controller and secure the X4 connector (which will no longer be used). The ATC/ESP indicator lamp would continue to function as an A TC indicator lamp, and should be designated as ATC only.

If a modied vehicle does not have the Bendix

ESP® system disabled, serious vehicle braking and performance issues could result, including unnecess ary ESP syst em inter vention s. This can lead to a loss-of-control of the vehicle.

In addition, remove all cab signage (e.g. visor labels, etc.) that were used to show that the Bendix ESP system was installed. Make any necessar y notations in the vehicle manual(s), so that drivers do not misunderstand which ABS options are installed on the vehicle.

Sensor Location Modications

The location and orientation of the Steering Angle Sensor and Y aw Rate Sensor must not be altered. When servicing, an identical component must be used in the same orientation (using OEM brackets & torque requirements). During installation follow the OEM leveling guidelines.

Steering Angle Sensor Re-Calibration

Whenever maintenance or repair work is performed to the steering mechanism, linkage, steering gear, adjustment of the wheel track, or if the steering angle sensor is replaced, a recalibration of the Steering Angle Sensor must be performed.

If the Steering Angle Sensor is not recalibrated, the yaw control system ma y not function properly, which can result in incidents leading to loss of vehicle control. See page 19 of this document for more

details on this procedure.

DYNAMOMETER TEST MODE

Bendix ATC and ESP systems must be disabled prior to conducting any dynamometer testing. When the Dynamometer Test Mode is engaged, the Bendix ATC EC‑80 Controller's brake control and engine control — along with drag torque contr ol and Bendix ESP system functions — are disabled. This test mode is used to avoid torque reduction or torque increase and brake control activation when the vehicle is operated on a dynamometer for testing purposes.

The Dynamometer Test Mode may be activated by pressing

and releasing the diagnostic Blink Code Switch ve times

or by using a hand‑held or PC‑based diagnostic tool. During Dynamometer Test Mode the AT C lamp remains ON. Bendix ESP EC‑80 Controllers will remain engaged in

the Dynamometer Test Mode even if power to the ECU is removed and re‑applied. To exit the test mode, press and release the Blink Code S witch three time s, or use a hand‑held or PC‑based diagnostic tool.

AUTOMATIC TIRE SIZE CALIBRATION

The ECU requires a precise rolling circ umference ratio between steer axle and dr ive axle tires in order for the Bendix ABS, ATC, and ESP systems to perform in an optimal manner. For this reason, a continuously monitoring process takes place in which the precise ratio is calculated. This calculated value is stored in the ECU memory provided the following conditions are met:

1. Rolling‑circumference ratio is within the permissible range;

2. Vehicle speed is greater than approximately 12 mph/19 kph;

3. No acceleration or deceleration is taking place; and

4. There are no active speed sensor Diagnostic Trouble Codes (DTCs).

The ECU is provided with a ratio value of 1.00 as a default setting. If the automatic tire size alignment c alculates a

different value, this is used to overwrite the original gure

in the memor y. This process adapts t he ABS and ATC function to the vehicle.

Acceptable Tire Sizes

The speed calculatio n for an exciter ring with 100 teeth is based on a default tire size of 510 revolutions per mile.

This gure is based on the actual rolling circumference of

the tires, which varies with tire size, tire wear, tire pressure, vehicle loading, etc.

The ABS response sensitivity is reduced when the actual rolling circumference is excessive on all wheels. For a 100 tooth exciter ring, the minimum number of tire revolutions per mile is 376, and the maximum is 665. T he ECU will set a Diagnostic Trouble Code (DTC) if the number of revolutions is out of this range.

In addition, the size of the steer axle tire s compared to the drive axle tires als o has to be within t he A BS system design. To avoid DTCs, the ratio of the effective rolling circumference of the steer a xle, divided by the effective rolling circumference of th e drive axle, must be bet ween

0.85 to 1.15.

Drive Axle/Additional Axle Wheel Speed Sensor DTC

The Bendix ATC and E SP systems are disabled. In a four sensor system, ABS on the affected wheel is disabled, but ABS on all other wheels remains active.

In a six sensor system, ABS remains active by using input from the remaining rear wheel speed sensor on the same side.

ATC Modulator DTC

The Bendix ATC and ESP systems are disabled. ABS remains active.

J1939 Communication DTC

The Bendix ATC and ESP systems are disabled. ABS remains active.

ECU DTC

The Bendix ABS, ATC, and ESP systems are disabled. The system reverts to normal braking.

The Bendix® ESP® system with t he EC- 80 Cont roller effectiveness relies on the accuracy of vehicle speed.

If a major ch a n g e on the tire siz e s is ma d e — su c h that

the odometer setting needs to be changed to correct

for the new tires — the Bendix ESP EC-80 Controller's

setting o f tire sizes must al so be reprogramme d to revised values.

SYSTEM IMPACT DURING ACTIVE DIAGNOSTIC TROUBLE CODES (DTCs)

ABS PARTIAL SHUTDOWN

Depending on which component the DTC is detected, the Bendix ABS, ATC, and ESP system functions may be fully or partially disabled. Even with the ABS indicator lamp illuminated, the Bendix ESP EC‑ 80 Controller m ay still provide ABS function on wheels that are not affected. The ABS system Controller shoul d be servic ed as soon as possible.

Steer Axle ABS Modulator DTC

ABS on the affected wheel is disabled. ABS and ATC on all other wheels remains active. The Bendix ESP system with the EC‑80 Controller is disabled.

Drive Axle/Additional Axle ABS Modulator DTC

ATC is disabled. ABS on the af fec ted wheel i s disabled. ABS on all other wheels remains active. The Bendix ESP EC‑80 system is disabled.

Steer Axle Wheel Speed Sensor DTC

The wheel with the DTC is still controlled by using input from the remaining wheel speed sensor on the steer axle. ABS remains active on the rear wheels. The Bendix ATC and ESP systems are disabled.

Voltage DTC

While voltage is out of range, Bendix ABS, A TC, and E SP systems are disabled. The system reverts to normal braking. When the co rrect voltage level is restored, full ABS and ATC function is available. The operating voltage range is 9.0 to 17.0 VDC for 12 volt systems, and 20 to 33.5 volts for 24 volt systems.

Steering Angle Sensor DTC