BENDIX SD-13-4986 User Manual

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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 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.

Label Shows ECU

Designation

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.

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	®	Previous		Key System Features	ECU	See
		(Bendix®	Key Components		Connector
EC 80™		EC-60™ ECU)		(ECU Designation Shown	Locations	Service Data
System Name						Sheet
		Designations		on the ECU Label)	Provided

ABS		“Standard”	ECU; Pressure Modulator Valves (PMVs);	ABS [Antilock Braking]	Two	SD-13-4983
			Four Wheel Speed Sensors.	(EC-80 ABS)
ATC			Items above, plus: Automatic Traction	ABS plus ATC [Traction Control]
		“Premium”	Control (ATC) Valve; Option of two more		Three	SD-13-4983
				(EC-80 ATC)
			Wheel Speed Sensors and PMVs.

			All items above, plus: Yaw Rate Sensor;	ABS plus ATC plus ESP		SD-13-4986
ESP®		“Advanced”	Steering Angle Sensor; Load Sensor;	[Yaw Control (YC) and	Four
						(This
			Steer-axle ATC valve; Brake Demand	Roll Stability Program (RSP®)].		Document)
			Sensor; and an Additional PMV	(EC-80 ESP)

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

▲Following the vehicle manufac turer ’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, fi ttings, etc. must be of equivalent size, type and strength as original equipment and be designed specifi cally 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 specifi cally 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.

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.

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.

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.

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

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

Straight Speed

Sensors

90° Speed

Sensors

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

Delivery (Port 2)

Supply (Port 1)

Electrical

M-40X™ Connector

Modulator

Exhaust (Port 3)

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	90° Connectors
Connector

FIGURE 4 - EXAMPLES OF STEERING ANGLE SENSORS

•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 J1939or 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

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

Bendix® RV-3™	Bendix® AT-3™	Bendix® DC-4®
Pressure	Traction Control	Double Check
Reducing Valve	Valve	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.

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 support Power Line Carrier (PLC). 24 volt models do not support PLC. See Figure 7 for more details.

ABS

ATC

Blink

ESP/

HSA

Bendix®

Input

Modu-

Retarder

Serial

Off-

ATC

Hill Start

™

PLC

lators

Sensors

Communication

Mud/Snow

Codes

RSP

eTrac

Voltage

Relay

J1939

Road

Aid Feature

system*

(PMVs)

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 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).

FIGURE 8 - POWER LINE WITHOUT PLC SIGNAL

FIGURE 9 - POWER LINE WITH PLC SIGNAL

The application of PLC technology for 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 oscilloscope can be used to measure or identify the presence of a PLC signal on the power line. The PLC signal is an amplitude and frequency-modulated signal.

Depending on the filtering and load on the power line, the PLC signal amplitude can range from 5.0 mVp-p to 7.05 Vp-p.

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

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 the ECU.

Bendix® WS-24™ Wheel Speed Sensors

Wheel speed data is provided to the Bendix ESP EC 80 Controller from the Bendix® WS-24™ wheel speed sensor (see Figure 2). Vehicles 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 wheel 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 sensors 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 80™ Controller into the ABS off-road mode. See "Optional ABS Off-Road Mode" on page 10 for further details. In some cases, ECUs may also be put into the ABS off-road mode by one of the other vehicle control modules, using a J1939 message to the Bendix ESP EC 80 Controller.

(If you need to know if a specific 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 part 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 flash constantly (at a rate of once per 2.5 seconds) to notify the 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 start 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 from 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 flash 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 transmission to engage the HS/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 vehicle 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 can 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 typically 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 Yaw Rate 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 YAS-70X™ Yaw Rate/Lateral Acceleration Sensors

Bendix® brand yaw rate/lateral acceleration sensors are used to provide the Controller an indication of vehicle lateral acceleration and rotation around the vertical axis. This information is provided to the Controller, utilizing a dedicated serial communications link that is shared 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 driver-applied air pressure to the service 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 flow 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 drive axle. 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 stability interventions, the Controller will activate 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 flashes 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 Controller 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 these 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 control 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 configured 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 configured for the Hill Start/ Hill Start Assist feature (HS/HSA), the retarder relay output pin is used to control the Hill Start status lamp. As a result, the vehicle 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. Typically, 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 ABS 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 can control the interaxle differential lock (AWD transfer case). This is recommended on AWD vehicles, but the ECU must be specially configured to provide this feature. E-mail ABS@bendix.com for more details.

INDICATOR LAMPS AND POWER-UP SEQUENCE

NOTICE: The vehicle operator should Verify 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 ignition power is applied, or remain illuminated, indicate the need for maintenance.

Dash Lamp Behavior for the

ABS

TRLR

HSA

Bendix® ESP® EC 80™ Controller

ATC

Mode

ABS

ATC/ESP Lamp

Trailer

HSA

Lamp

ABS Lamp

Lamp

Comments

If any of the described lamp behaviors

Ignition on - start up

ON for

do not occur — or if the lamp remains

Startup

ON for 2.5

on during operation — have the vehicle

[trailer with Power Line

three (3)

seconds*

serviced by a qualified mechanic as

Carrier (PLC)]

seconds*

seconds**

seconds*

soon as possible to restore full system

Vehicle

functionality.

** illuminate the trailer ABS indicator lamp

Some vehicle manufacturers may

3 seconds after ignition

Lamp OFF*

Lamp

at power up regardless of whether a

[with no Diagnostic

Lamp OFF**

OFF*

PLC signal is detected from the trailer or

Trouble Codes (DTCs)]

not. Consult the vehicle manufacturer’s

documentation for more details.

		Normal		Lamp OFF	• Uses dash switch
	ABS	Normal	Lamp flashes	Lamp OFF	• Not for firm road surfaces
					• Not for firm road surfaces
					• Allows more wheel lock-up (less ABS intervention)
	Off-Road		slowly (every 2.5		• Allows more wheel lock-up (less ABS intervention)
	Off-Road		slowly (every 2.5		• Mode only applies under 25 mph (Over 25 mph, the system reverts to
	Mode	During an ATC	seconds)	Flashes quickly
Operation	Mode	During an ATC	seconds)		full ABS - including ATC/ESP — and upon exiting off-road mode, the
		Event
					ATC lamp extinguishes.)
		-— OR, depending on vehicle options (a vehicle can have either ABS off-road or HSA) —
				During HSA Event		Lamp OFF
Mode	Vehicles with Hill Start Aid (HSA):			During HSA Event		Lamp OFF
	Vehicles with Hill Start Aid (HSA):					• The HSA lamp is illuminated only at power-
		During HSA Mode				• The HSA lamp is illuminated only at power-
		During HSA Mode		HSA Manually Disabled		Flashes	up, or if an HSA DTC is present
Special		(“Hill Start” / “Hill Start Assist”)		HSA Manually Disabled		slowly	up, or if an HSA DTC is present
						slowly
	Deep			Flashes slowly
		Normal	OFF	(every 2.5	• Uses dash switch
		Normal	OFF	(every 2.5
	Mud/			seconds)
	Mud/			seconds)	• Increases allowable wheel slip during ATC interventions
	Snow/	During an			• Increases allowable wheel slip during ATC interventions
	Snow/				• Not for firm road surfaces
	Mode		OFF	Flashes quickly	• Not for firm road surfaces
	Mode	ATC/ESP	OFF	Flashes quickly
		Event
During an Automatic Traction Control (ATC) Event				Flashes quickly	• Reduces wheel slip during acceleration at low speeds
				Lamp ON	• Disables ATC monitoring functions
	During Dynamometer Mode			(ATC	• When not in Dynamometer Mode, an illuminated lamp indicates an
				Disabled)	ATC DTC is present
		During an ESP Event		Flashes quickly	• System intervenes to reduce the risk of rollovers, loss-of-control, etc.
	ABS System			Power		ATC/ESP System
	ABS System		Application			ATC/ESP System
	Status Indicators					Status Indicator
	at Start-Up		0.5 1.5 2.0 2.5 3.0 (sec.)			at Start-Up			Power
	Powered Vehicle ABS		ON						Application
		Indicator Lamp	OFF					0.5 1.5 2.0 2.5 3.0 (sec.)
		Trailer ABS				ATC/ESP		0.5 1.5 2.0 2.5 3.0 (sec.)
		Trailer ABS	ON			ATC/ESP		ON
		Indicator Lamp	OFF			enabled		OFF
	(PLC Detected)**		OFF					OFF
		Trailer ABS	ON			No ESP		ON
	Indicator Lamp**		ON			No ESP		OFF
	(PLC Not Detected)		OFF			or ATC

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

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 ATC/ ESP lamp for approximately 2.5 seconds when ignition power is applied, after which the lamp will extinguish if no DTCs are detected. The Controller will continuously illuminate the ATC/ESP Indicator Lamp whenever ESP or ATC is disabled due to a DTC.

During an ESP or ATC intervention, the lamp will flash rapidly (2.5 times per second). When the Controller is placed in the ATC Mud/Snow (off-road) mode, the lamp will flash 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.

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

Right Steer	Right Drive	Right
Right Steer	Right Drive	Additional
	Driver
Left Steer	Left Drive	Left
		Additional

FIGURE 11 - VEHICLE ORIENTATION (TYPICAL)

After the performance of the configuration test, the Bendix

ESP EC 80 Controller will perform a Bendix-patented PMV and TCV Chuff Test. The Chuff Test is an electrical and pneumatic PMV test that can assist maintenance personnel in verifying proper PMV wiring and installation.

When ignition power is applied, each modulator solenoid is briefly energized. If the air system is fully charged and the service brake pedal is depressed during ignition, the modulator creates a single, sharp audible “chuff” of air pressure. The modulators are energized in a certain pattern: right front; left front; right rear; then left rear.

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 perform 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 configured to do so) will perform a test to cross-check the trailer PMV operation with the vehicle stop lamps. If the trailer PMV circuit is 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 corresponding repairs are successfully conducted. The ESP/ATC dash indicator will also illuminate when there are active ABS, ATC or ESP DTCs.

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

ABS OPERATION

Bendix® ABS uses wheel speed sensors, ABS pressure modulator valves, and an ECU to control either four or six wheels of a vehicle. The Bendix ESP EC 80 Controller monitors individual wheel turning motion during braking, 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 activate the pressure modulator valves to automatically reduce the brake pressure at one or more of the wheel ends. By these actions, the ABS 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 pressure 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 traction, or areas of poor traction (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 Configuration)

For vehicles with dual drive axles (6x4) using a 4S/4M configuration, one ABS modulator controls both of the right-side rear wheels; the other modulator controls both of the left-side rear wheels. Both wheels on each side receive equal brake pressure during an ABS stop. The rear wheel speed sensors must be installed on the axle with the lightest load.

Dual Rear Axle Control (6S/6M Configuration)

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

6x2 vehicles can utilize a 6S/5M configuration, 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 surfaces with low traction, application of the retarder can lead to high levels of wheel slip at the drive axle wheels, which can adversely affect vehicle stability.

To 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 ABS off-road mode (on vehicles equipped with this optional feature), it will switch off the retarder only when ABS is active on a steer axle wheel and a drive axle wheel.

Optional ABS Off-Road Mode

On some road conditions, particularly when the driving surface is soft, the stopping distance with conventional ABS may be longer than without 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. Although vehicle stopping distance with a locked wheel (in the absence of ABS) may be shorter than

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

Bendix ESP EC 80 Controllers have an optional dash switch that initiates a modified ABS control mode (known as "off-road ABS") that more effectively accommodates these soft road conditions to shorten stopping distance 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 flash 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 ATC/ESP dash lamp will illuminate to indicate to the driver that the stability system 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 flashing ABS Indicator Lamp indicates to the driver that the ABS off-road function is engaged. To exit the ABS off-road mode, depress and release the switch. A new ignition cycle will 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 specifically for this configuration 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 stability during braking, Automatic Traction Control (ATC) 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 configured to use engine torque limiting and/or differential braking to control wheel spin. For optimal ATC performance, both methods are recommended.

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

Bendix ESP EC 80 Controllers operate the ATC/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 orATC event (the lamp will flash 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 flash steadily at a rate of once every 2.5 seconds). This notifies 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 ATC/ESP lamp.

Differential Braking

Differential braking within ATC is automatically activated when drive wheel(s) on one side of the vehicle are spinning excessively. This typically occurs on road surfaces with patches of ice. The traction 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 ATC 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 ATC Differential 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-axle wheel slip. This is commu nicated to the engine control module (using J1939), 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 driving situation, the 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 ATC system is decreased when driving through a curve for improved stability.

Disabling ATC Engine Control and the Bendix SMART ATC System

ATC Engine Control and the Bendix SMART ATC 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 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 flash steadily at a rate of once every 2.5 seconds to confirm 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 lowtraction road surfaces during down-shifting or retarder braking.

BENDIX ESP EC 80 ABS WITH STABILITY CONTROL

Overview

The Bendix ESP system with the EC 80 Controller reduces the risk of rollovers, jackknifing 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

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 higherfriction 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.

FIGURE 12 - RSP EXAMPLE

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.

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 13 - YAW CONTROL EXAMPLE

Bendix® Roll Stability Program (RSP®)

Bendix RSP — an element of the overall Bendix® ESP® system with the EC-80™ Controller — 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. See Figure 12.

Yaw Stability

Yaw stability counteracts the tendency of a vehicle to spin about its vertical axis. During operation — if the friction between the road surface and the tires is not sufficient 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 influence yaw stability are: wheelbase, suspension, steering geometry, weight distribution front to rear, and vehicle track width.

Yaw Control

Yaw control responds to a wide range of lowto highfriction surface scenarios including rollover, jackknife and loss-of-control. It is the recommended system for all power vehicles and especially critical for tractors pulling trailers. In the case of vehicle slide (over-steer or understeer 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 with or without the operator applying the brake — and even when the throttle is being applied.

To minimize unexpected 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 traffic 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 system with the EC 80 Controller is designed and optimized for trucks and for tractors that tow single trailers. If a tractor equipped with Bendix ESP is used to power multiple trailer combinations (known as “doubles” or “triples”) the effectiveness of the Bendix ESP system may be greatly reduced. Extremely careful driving is always required when towing doubles or triples. Excessive speed and aggressive maneuvers — such as sharp turns, sudden 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 significant side forces on the vehicle and any towed vehicles.

To Maximize The Effectiveness Of The Bendix® ESP® System with the EC 80™ Controller:

•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 Modifications

If the vehicle’s chassis components are altered (for example, a wheel base extension or reduction; tag axle addition or removal; a major body change such as conversion of a tractor into a truck; or an axle, suspension, or steering system component modification) the Bendix® ESP® system must be disabled. Have a qualified mechanic replace the Bendix ESP EC 80 Controller with a Bendix® 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 ATC indicator lamp, and should be designated as ATC only.

If a modified vehicle does not have the Bendix®

ESP® system disabled, serious vehicle braking and performance issues could result, including unnecessary ESP system interventions. 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 necessary notations in the vehicle manual(s), so that drivers do not misunderstand which ABS options are installed on the vehicle.

Sensor Location Modifications

The location and orientation of the Steering Angle Sensor and Yaw 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 may 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 control 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 five times or by using a hand-held or PC-based diagnostic tool.

During Dynamometer Test Mode the ATC 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 Switch three times, or use a hand-held or PC-based diagnostic tool.

AUTOMATIC TIRE SIZE CALIBRATION

The ECU requires a precise rolling circumference ratio between steer axle and drive 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 calculates a different value, this is used to overwrite the original figure in the memory. This process adapts the ABS and ATC function to the vehicle.

Acceptable Tire Sizes

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

This figure 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. The 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 tires compared to the drive axle tires also has to be within the ABS system design. To avoid DTCs, the ratio of the effective rolling circumference of the steer axle, divided by the effective rolling circumference of the drive axle, must be between 0.85 to 1.15.

The Bendix® ESP® system with the EC-80 Controller effectiveness relies on the accuracy of vehicle speed.

If a major change on the tire sizes is made — such that the odometer setting needs to be changed to correct forthenewtires—theBendixESPEC 80Controller's setting of tire sizes must also be reprogrammed 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 may still provide ABS function on wheels that are not affected. The ABS system Controller should be serviced 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 affected wheel is 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.

Drive Axle/Additional Axle Wheel Speed Sensor DTC

The Bendix ATC and ESP 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.

Voltage DTC

While voltage is out of range, Bendix ABS, ATC, and ESP systems are disabled. The system reverts to normal braking. When the correct 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