Bendix EC-17 ANTILOCK TRACTION CONTROL User Manual

Bendix® EC-17™ AntiLock - Traction Controller

MOUNTING

HOLES

(4)

SD-13-4788

EC-17N™ CONTROLLER

WITHOUT LED DIAGNOSTICS

18 PIN

CONNECTOR

FIGURE 1 - EC-17

30 PIN

CONNECTOR

DIAGNOSTIC

DISPLAY

™

& EC-17N™ ANTILOCK TRACTION CONTROLLERS

DESCRIPTION

GENERAL The EC-17™ is an electronic antilock controller. It is the base

component in a family of full vehicle wheel control antilock systems for buses, trucks and truck tractors. In addition to the antilock function, the EC-17™ controller can be assembled and programmed to provide an optional traction control feature. Figure 1 shows the basic EC-17™/EC-17N controller configurations.

Designed to minimize the potential of brake lock up on all wheels during aggressive braking, the EC-17™ controller based antilock system provides the vehicle with a high degree of stability and steerability during braking. In most cases, vehicle stopping distance is also reduced. The antilock portion of the EC-17™ controller based system minimizes wheel skid during hard or aggressive braking. By controlling wheel skid at all wheels on the vehicle, optimum steering control and stopping distance is obtained.

Traction control, an optional feature in the full vehicle wheel control antilock system, helps improve vehicle traction during acceleration in adverse road conditions. Integrated with antilock logic, traction control monitors wheel speed

EC-17™ CONTROLLER

WITH LED DIAGNOSTICS

information from the sensors during acceleration, as well as braking. The system helps maintain vehicle stability on hazardous road surfaces and improves driveability and safety .

The EC-17™ controller contains a self configuring or learning feature that allows it to be configured by the user when installed on the vehicle. Because of this feature, all EC-17

™

controllers contain all the features and options available and will activate the specific features required for the vehicle it is installed on. The EC-17™ controller can be installed on vehicles with only antilock or vehicles using the traction control feature. The procedure for activating the self configuring feature is contained in the section entitled “Configuring The EC-17™ Controller”.

In order to provide full vehicle wheel control antilock, the EC-17™ controller is used in combination with the following components:

- Four or six wheel speed sensors

- Four air pressure modulator valves

- One dash mounted antilock condition lamp

- One service brake relay valve

™

OR M-22

™

MODULATORS

M-21

SPRING BRAKES

REAR AXLE SERVICE &

COMPUTER

DIAGNOSTIC

BATTERY

ENGINE

™

OR AT-2

™

ELECTRONIC

CONTROL MODULE

AT-1

ANTILOCK TRACTION

™

EC-17

ASSEMBLY

CONTROLLER

VALVE

SERVICE BRAKE

SENSOR

EXCITER

WHEEL SPEED

TANDEM REAR AXLE

TRACTION LAMP

RETARDER DISABLE SWITCH

VALVE

QUICK

RELEASE

™

ANTILOCK LAMP

OR M-22

™

TRACTION ENABLE SWITCH

MODULATORS

M-21

FIGURE 2 - EC-17™ ANTILOCK TRACTION CONTROLLER SYSTEM SCHEMATIC

SENSOR

WHEEL SPEED

EXCITER

When programmed to provide traction control in addition to antilock, the following components are added:

- One traction solenoid (incorporated into the relay valve)

- One dash mounted traction condition lamp

- Serial connection to engine control module (for vehicles programmed for torque limiting feature)

- Traction disable wiring and switch

PHYSICAL

The EC-17™ controller electronics are contained in a nonmetallic housing and are environmentally protected by an epoxy compound. The design of the digital electronics are intended to provide a high degree of protection from radio, electromagnetic and environmental interference.

The patented optional light emitting diode (LED) display and magnetically actuated reset switch is incorporated in the housing for troubleshooting and diagnostic purposes.

Two electrical connectors, located in the controller housing opposite the diagnostic display (if so equipped), connect the EC-17™ controller to antilock and traction system components: one 30 pin and one 18 pin connector. The optional traction solenoid is linked to the 18 pin connector using a 2 pin Deutsch connector. The optional traction solenoid is located in the upper portion of the antilock traction relay valve assembly . (See Figure 3.)

MOUNTING

The EC-17™ controller is available in two different mounting styles. One model, shown in Figure 1, is a stand-alone. It is intended for bracket mounting to a frame member and is not attached to an antilock relay valve.

The other EC-17™ controller is designed to be mounted on one of four different valves. All of the valves provide the relay

ANTILOCK TRACTION

ASSEMBLY

CONTROLLER

EC-17

™

function and replace the standard service relay on antilock equipped vehicles. In some instances the valves also provide specialized functions. When the EC-17™ controller is mounted on any of these valves, the result is a final assembly with its own model designation. Refer to the chart below and Figure 3.

AntiLock Added Function Vehicle Designation (Valve +

Valve Provided Application EC-17™ Controller)

™

AR-1 AR-2

ATR-1 ATR-2

™

™ ™

None All CR-17™ Controller Relay Bobtail Brake Tractors Only CR-18™ Controller Relay Proportioning

Traction All AT-1™ AntiLock Traction

Traction & Bobtail Tractors Only A T-2™ AntiLock Traction

Brake Proportioning

EC-17™ CONTROLLER INFORMATIONAL INPUTS AND COMMAND OUTPUTS

GENERAL

The EC-17™ controller receives information from several components in the antilock system and, based on these inputs, issues commands or delivers information. Some portions of the EC-17 commands and information. (See Figure 5.)

INPUTS

- Wheel speed information is provided to the EC-17

controller via a wiring harness from individual wheel speed sensors at the vehicle wheels (See Figure 4). Working with an exciter or tone ring, wheel speed sensors provide information to the EC-17™ controller in the form of an AC signal which varies in voltage and frequency as the speed of the wheel increases or decreases. The EC-17™ controller is designed to receive wheel speed information, from various wheel speed sensor models, at the rate of 100 pulses (86 pulses if so configured) per wheel revolution. The EC-17 controller is able to simultaneously receive, and individually interpret, speed signals from up to six wheel speed sensors. Vehicle drive configuration and whether the traction control feature is in use determines the number of speed sensors that must be used. A vehicle with a single rear axle drive (4 x 2, 4 x 4 or 6 x 2) requires 4 speed sensors for both antilock and traction operation. A vehicle with two rear drive

™

controller both receive and deliver

™

CONNECTOR

(TO TRACTION

TRACTION

RELAY

FIGURE 3 - EC-17™ CONTROLLER W/ANTILOCK TRACTION RELAY VALVE

TRACTION SOLENOID

(IN HOUSING)

2-PIN

SOLENOID)

™

WS-24

SENSOR

™

WS-20

SENSOR

90° SPEED

SENSORS

™

WS-24

SENSOR

FIGURE 4 - WS-20™ AND WS-24™ WHEEL SPEED SENSORS

STRAIGHT SPEED

SENSORS

WS-20

SENSOR

™

, or

™

modulators

™

, M-22

™

quick release

™

and M-22

™

and or M-32QR

™

Note: M-21

are shown in the diagrams in this

document — newer model M-30

M-32

modulators - except

™

) may be replaced by M-32

™

are used on many vehicles. Earlier

modulators (M-21

M-30

or M-32QR

for front axle use where there

is not a quick release valve (e.g.

a Bendix QR-1

valve) and then only M-32QR

modulators are permissible. We do

™

modulators with earlier

™

not recommend replacing M-32

M-32QR

modulators.

™

wheel

™

Note: WS-20

wheel speed sensors

speed sensors are

are used on many

shown in this document

— newer model WS-24

™

wheel

vehicles. WS-24

speed sensors may be

wheel

™

wheel speed

™

wheel speed sensors.

We do not recommend

replacing WS-24

used to replace WS-20

speed sensors with

WS-20

sensors.

FIGURE 5 - EC-17™ ANTILOCK TRACTION CONTROLLER SYSTEM WIRING SCHEMATIC

axles (6 x 4) requires 4 speed sensors for antilock only operation, but have the option to use 6 speed sensors for enhanced performance of both antilock and traction operation.

- Vehicle power is supplied to the EC-17™ controller from the ignition switch through a 30 amp fuse. The electrical ground for the EC-17™ controller is the vehicle chassis.

- A connection for a traction enable switch is provided, and used when the optional traction feature is installed. The switch allows traction to be turned on or off manually .

- A TC requires J1922/J1939 drivers requested torque. This input is necessary to engage differential braking on units built after mid-year 2000.

OUTPUTS

- Modulators - The Bendix® M-22™ modulator, is the means

by which the EC-17™ controller modifies driver applied air pressure to the service brakes. The modulator is an electrically controlled air valve located near the service actuator(s) it controls. It is the last valve that air passes through on its way to the brake actuator . A wiring harness connects the modulator to the EC-17™ antilock controller. Solenoid valves contained in the modulator provide the electrical interface between the EC-17™ controller electronics and the air brake system. The EC-17™ controller is able to simultaneously and independently control four individual modulator assemblies. When vehicle power is supplied to the EC-17™ controller, a modulator “chuf f” test is performed. When the brake pedal is depressed and the ECU is powered via the ignition switch, the patented modulator “Chuff” test is audible. A properly wired modulator will exhaust air with a sharp (or crisp) audible “Chuff”. On ECU’s manufactured prior to mid-year 2000, the hold solenoid of a modulator is energized three times longer than an exhaust solenoid while the “Chuff” test is being executed. If the modulator hold and exhaust solenoid wires are reversed the audible “Chuff” is not crisp because of the extended exhaust energization. After mid-year 2000, the hold solenoid of the modulator is energized twice while the exhaust solenoid is energized once. If the modulator hold and exhaust solenoid wires are reversed the modulator will exhaust twice during a “Chuff”. The vehicle modulators will “Chuff” in the sequence: right front, left front, right rear , left rear. It will execute this exhaust sequence twice, for a total of eight exhausts. Both patented audible “Chuff” tests help the mechanic verify when the modulators are functional and connected correctly without needing additional test equipment. If an issue is detected with the modulators, proceed with modulator troubleshooting or compare the modulator wiring to the vehicle wiring schematic found in Figure 5.

- An AntiLock dash light through an electrical relay is connected to, and controlled by , the EC-17™ controller and serves as a means of advising the driver of the condition of the antilock system.

™

M-30

MODULATOR

SUPPLY

(PORT 1)

ELECTRICAL

CONNECTOR

FIGURE 6 - M-30™, M-32™, AND M-32QR™ MODULAT ORS

EXHAUST

(PORT 3)

DELIVERY

(PORT 2)

™

M-32QR

MODULATOR

™

M-32

MODULATOR

- Two control link connections to the engine or transmission retarder and its relay are provided on the EC-17™ controller.

One control link or the other can be utilized, but not both on the same vehicle. The hardware for one control link conforms to S.A.E. standard 1708 and the protocol, or coded language used, conforms to S.A.E. standard J1922. The other control link conforms to S.A.E. standard J1939. Use of a control link allows the EC-17™ controller to temporarily disable the retarder during certain modes of operation. Units built after mid-year 2000 have improved retarder operation, allowing the retarder to re-enable sooner following an ABS event. While the EC-17™ controller is capable of this function, and connections are provided, it is not always used. Use of the retarder disable function is not essential but highly recommended for vehicles equipped with a retarder .

Note: The EC-17™ controller can also disable the retarder

using the same S.A.E. J1922 or S.A.E. J1939 protocol it uses to control the traction control, engine torque limiting feature. For this redundant retarder disable to function, the EC-17™ controller must be connected to the engine control module (as would be the case if the EC-17™ controller is programmed for the traction control, torque limiting feature).

- The diagnostic link enables the EC-17™ controller to "report" its operating condition to an external computer using the Bendix diagnostic communications interface hardware in response to certain commands it receives from software like Bendix ACom® for Windows*. The EC-17™ controller diagnostic link hardware conforms to S.A.E. standard J1708. The protocol, or coded language used, conforms to S.A.E. standard J1587. While connections are provided for this function, it is not always used. The use of the diagnostic link is essential for the servicing and reconfiguration of the EC-17N™ controller. The diagnostic link is also used by

the EC-17™ controller to request additional information and to assist diagnostics and troubleshooting.

* Windows is a registered trademark of Microsoft Corporation.

If the EC-17™ controller is programmed for traction control, it contains the following outputs:

- A connection to the engine's electronic control module allows the EC-17™ controller to reduce engine torque under certain circumstances.

- A traction dash light is connected to and controlled by

™

the EC-17

controller and serves as a means of advising

the driver of the condition of the traction control system.

- A connection to the traction solenoid (located in the upper portion of the antilock traction relay valve (see Figure

3) is provided via a 2 pin Deutsch connector.

OPERA TION - ANTILOCK (ABS)

PHILOSOPHY

The Bendix® EC-17™ antilock system uses individual sensors, modulators and an electronic controller to control the four vehicle wheel ends. By monitoring the deceleration rate during braking, and subsequently adjusting the brake application pressure at each wheel, the EC-17™ controller is able to improve braking between the vehicle tire and the road surface it is on, while maintaining vehicle stability .

The rear axle brakes are controlled independently; therefore brake application pressure at an individual wheel is adjusted solely on the basis of its behavior on the road surface on which it is traveling.

While each steering axle brake is under the control of an individual modulator, the EC-17™ controller does not treat these brakes independently . The EC-17™ controller uses a modified individual control philosophy for the steering axle brakes. This is done in order to minimize "steering wheel pull" in the event each wheel is traveling on a different road surface (for example, ice close to the curb and a dry crown). Essentially the EC-17™ controller controls the braking force differences between the two brakes.

The wheel on dry pavement is initially given less braking force and is brought up to optimum during the stop, while the wheel on ice attempts to maintain optimum braking during the entire stop.

In the case of vehicles equipped with tandem rear axles (6x2, 6x4), the wheel speed sensors are installed at the wheels on the axle that is most likely to lock first. A single modulator controls both curb side brakes on the tandem, and another modulator controls both brakes on the driver's side of the tandem. With this arrangement of speed sensors and modulators, both brakes on one side of the tandem are treated as one since they will most likely be on the same type of road surface.

NON ANTILOCK BRAKE APPLICATION

During normal braking, air pressure from the brake valve enters the control port of the service relay valve. The service relay delivers air to, and through, the antilock modulator located near the braked wheel, and into the brake actuator. The service brakes are thus applied. If the wheel sensors do

™

not detect an impending wheel lock up, the EC-17

controller does not initiate any corrective action and the vehicle comes to a stop in a normal fashion.

ANTILOCK BRAKE APPLICATION

If a service brake application is made and the wheel speed sensors detect an impending wheel lockup, the EC-17 controller will immediately begin modification of the brake application using the antilock modulator(s) at the affected wheel(s). Solenoid valves contained in the modulator (hold and exhaust) are energized and de-energized by the EC-17™ controller in order to modify the brake application. When a solenoid coil is energized, its shuttle moves. Depending upon the function of the specific solenoid, it either opens or closes, thereby causing the exhaust or reapplication of air pressure to the brake actuator. The solenoids in each modulator are controlled independently by the EC-17™ controller. By opening and closing the solenoid valves in the appropriate modulator, the EC-17 controller is actually simulating what drivers do when they "pump the brakes". It must be remembered however that unlike the driver, the EC-17™ controller is able to "pump" each brake on the vehicle independently and with far greater speed and accuracy .

OPERA TION - TRACTION CONTROL (A TC)

PHILOSOPHY

Traction control is a natural extension of antilock. Just as antilock helps vehicle control and stability during braking, traction control helps during vehicle acceleration. The wheel speed sensors not only detect rapid decreases in wheel speed for antilock but also detect unreasonably high increases for traction control. With traction control, a spinning wheel is instantly detected and compared with the other wheels on the vehicle, both front and rear. Two methods are used to control wheel spin, torque limiting and differential braking. Both methods could be configured within the ECU independently or together. On units manufactured af ter midyear 2000, only torque limiting can be configured independently . On units manufactured after mid-year 2000 it will also be necessary that the J1922 or J1939 serial link protocol communicate the vehicle throttle position or the A TC will not function.

With traction control, a spinning wheel is instantly detected and compared with the other wheels on the vehicle, both front and rear. Two different methods are used to control wheel spin; torque limiting and differential braking. Depending upon vehicle type, speed and road (surface) condition, each

™

method provides a unique and desirable type of wheel spin control. Ideally both methods are used to control vehicle traction. While all EC-17™ controllers are capable of providing wheel control antilock and traction control (utilizing both methods of control), not all systems will be configured for both methods. Depending upon the vehicle, either or both traction control methods will be activated during the self configuration procedure.

Torque Limiting - In order for the torque limiting control feature to be used, the vehicle must be equipped with an electronically controlled engine throttle. The torque limiting feature allows the EC-17™ controller to reduce engine torque to a suitable level for the available traction. Torque limiting helps to minimize the amount (or speed) of wheel spin. It is especially useful in helping to minimizing a power jackknife and when all drive wheels are on an equally slippery surface.

Differential Braking - In order for the differential braking control to be used, the vehicle must be equipped with an antilock traction relay valve such as the Bendix® A TR-1™ or A TR-2™. Additionally after mid-year 2000 the ECU requires J1922/ J1939 drivers torque request. The ATR-1™ and A TR-2™ relay valves contain a solenoid assembly which provides this feature. The differential braking feature allows the EC-17 controller to gently pump the brake on the spinning wheel. Since the vehicle's differential tends to drive the wheel that presents the least resistance (the wheel on the most slippery surface), a slight brake application to this wheel only , forces the differential to drive the stationary or slowly spinning wheel. Differential braking can be activated only when vehicle speed is under 25 MPH and one drive wheel is spinning faster than the other(s).

Traction Enable/Disable Switch - The traction control enable/ disable switch allows the operator to engage or disengage the traction control system as necessary . The switch may be used to either engage or disengage the traction control system while the vehicle is in motion. It must be noted however that while the traction control will disengage while the vehicle is in motion it will not re-engage (even with the switch in the engaged position) until the vehicle comes to a complete stop.

TRACTION CONTROL AT VEHICLE SPEEDS OF 0 TO 25 MPH

When wheel spin is detected and the vehicle is stopped, or moving at any speed up to 25 mph, the EC-17™ controller simultaneously executes the following operations:

It instantly blinks the traction dash lamp to advise the driver that a wheel spin is occurring.

If the torque limiting feature is active, the EC-17™ controller uses its link to the engine control module and sends a signal to reduce engine torque to a level suitable for the available traction.

If the differential braking feature is configured into the system, the EC-17™ controller energizes the solenoid in the ATR valve which then applies air to each of the rear axle

modulators. Because the modulators are controlled by the

™

EC-17

controller, the solenoid valves in the appropriate modulator are opened and closed to gently pump the brake on the spinning wheel only. This gentle brake application forces the differential to drive the stationary or slowly spinning wheel.

Once wheel spin is eliminated, the dash lamp goes out and the traction system disengages control.

In the event that extended periods of traction operation are experienced, without vehicle motion being detected, the ABS traction system will disable traction control to prevent brake fade. The system will re-enable traction control after a short period of time.

TRACTION CONTROL AT VEHICLE SPEEDS ABOVE 25 MPH

If wheel spin occurs at any speed above 25 mph, the EC-17™ controller will instantly blink the traction dash lamp to advise the driver that a wheel spin is occurring.

If the torque limiting feature is programmed in, the EC-17 controller uses its link to the engine control module and sends a signal to reduce engine torque to a level suitable for

™

the available traction. NOTE: THE EC-17™ CONTROLLER WILL NOT SIGNAL THE

ATR™ V AL VE TO APPL Y THE BRAKES, EVEN SLIGHTL Y, A T ANY SPEED ABOVE 25 MPH.

ANTILOCK AND TRACTION SYSTEM OPERATION DURING COMPONENT FAILURE

The Bendix® EC-17™ controller handles equipment failure using a conservative fail safe philosophy . Any single electrical failure of a component devoted to antilock or traction control results in simultaneous illumination of the appropriate condition lamp on the dash, a disabling of part or all of the antilock or traction system, and reversion to standard braking on wheels no longer under EC-17™ controller control.

Depending upon the type of failure and its position of occurrence, the EC-17™ controller disables all or only a portion of the antilock and traction system. A power or controller failure, however, will result in complete disabling of both systems and reversion to standard (non-antilock) braking is still available on all wheels.

There are a variety of ways to clear diagnostic trouble codes detected by the system. In most cases, the system will reset the diagnostic trouble code condition when the source of the original diagnostic trouble code has returned to a normal state for a period of time. Isolated diagnostic trouble codes are able to be reset by the system, but repeated occurrence (and self-clearing) of some diagnostic trouble codes will require a manual reset. This is done to aid in the troubleshooting of intermittent diagnostic trouble codes. The PC interface (or optional magnetic reset) is used to manually clear diagnostic trouble codes.

™

AUTO CALIBRATION

For optional ATC performance the ECU utilizes a feature referred to as auto calibration. Auto calibration allows the ECU to compensate for various tire sizes throughout the life of the vehicle. As there are many conditions that can result in the appearance of a change in the tire size, several items must be satisfied before the auto calibration feature is active. The auto calibration feature would automatically change the ECUs imbedded tire sizes if the difference exceeded approximately 8%. If issues occur with your A TC due to tire size changes please contact 1-800-AIR-BRAKE or 1-800-247-2725 for assistance.

SINGLE FAILURE

The following list and chart describes how the antilock and traction systems respond to a specific component failure.

(Note: right and left; front, mid and rear are determined from the driver's seat. Left front is therefore the corner closest to the driver.)

For example, if the right mid sensor ("RM Sensor" on the chart) fails, front and rear antilock will still be operative. Traction will be disabled. On those axles where antilock is disabled the system reverts to standard air braking.

Front modulator - If a front modulator fails, antilock on that wheel is disabled. Antilock and traction on all other wheels remains active.

Rear modulator - A rear modulator failure disables the traction system. Antilock on that wheel will also be disabled, but antilock on all other wheels remains active.

Front sensor - The wheel is still modulated using input from the opposite sensor on the front axle. The traction system is disabled.

Mid or rear sensor - In a four sensor system, antilock on that wheel(s) is disabled, but antilock on all other wheels remains active. In a six sensor system, antilock remains active using input from the remaining functional sensor. In both the four and six sensor system traction control is disabled.

Controller - Antilock and traction are disabled. The system reverts to standard air braking.

Traction solenoid - Traction control is disabled. Antilock remains active.

RIGHT FRONT

DRIVER

FRONT OF VEHICLE

LEFT FRONT

RIGHT MID

LEFT MID

RIGHT REAR

LEFT REAR

SYSTEM STILL OPERATING (YES/NO)

Failed ABS Front ABS Rear Traction Std.

Device

RF Sensor YES YES YES YES NO YES LF Sensor YES YES YES YES NO YES RM Sensor YES YES YES YES NO YES LM Sensor YES YES YES YES NO Y E S RR Sensor YES YES YES NO LR Sensor YE S YES NO1YES NO YES RF Modulator YES NO YES YES YES YES LF Modulator NO YES YES YES YES YES RR Modulator YES YES YES NO NO YES LR Modulator YES YES NO YES NO YES Controller NO NO NO NO NO YES Tract. Solenoid YES YES YES YES N0 YES Engine Control Module Voltage

DIAGNOSTIC TROUBLE CODE LOCATION

ABS is still available in 6 sensors system if mid sensor is functional

When ECM wiring or voltage "corrects" itself, system is restored.

FIGURE 7 - EC-17™ CONTROLLER LED DIAGNOSTIC DISPLAY

Left Right Left Right Braking

YES YES YES YES NO YES

NO NO NO NO NO YES

RER

RHT

LFT

TRC

MOD

SEN

ECU

VLT

REAR

RIGHT

LEFT

TRACTION

MODULATOR

SENSOR

ECU

VOLTAGE

NO YES

FRT

MID

FRONT

MIDDLE

Engine Control Module - If the engine control module (ECM) or the wiring from the EC-17™ controller to the ECM fails, traction control is disabled. Antilock remains active.

Voltage - If system voltage is out of range, antilock and traction are disabled. The system reverts to standard air braking.

MULTIPLE FAILURES

In the event that multiple failures occur, the dash lamp will react as it normally would during a single failure, and the EC-17™ controller equipped with LEDs will show one diagnostic trouble code at a time. When the first diagnostic trouble code is fixed and the system is reset, the next diagnostic trouble code area will appear at the LEDs. This way , the driver or mechanic does not lose track of diagnostic trouble code areas, and the system is not restored until each and every error is corrected and the EC-17™ controller is cleared of all diagnostic trouble codes.

REAR OF VEHICLE

SWITCH

RESET

ANTILOCK AND TRACTION WIRING

GENERAL NOTES

The wires that carry information and power into and out of the EC-17 at a connector. The wire groups or wire harnesses along with the connectors are most often specified and/or supplied by the vehicle manufacturer. The connectors used on the EC-17™ controller are illustrated in Figure 5. The wiring harnesses and connectors are weather resistant and the wires that enter the connector are sealed to the connector. The wire gauge used in the wire harnesses is specific to the task performed.

When diagnosing wiring in the antilock system the following general rules apply and should be followed where applicable:

1. It is generally advisable to replace a wire harness rather

2. Do not pierce wire insulation when checking for continuity.

3. Do not spread or enlarge individual pins or sockets during

4. Always check the vehicle handbook for wire and

5. While the retarder disable, serial link, and traction on/off

™

controller are generally grouped and terminate

than repair individual wires in the harness. If a splice repair must be made, it is important that the splice be properly soldered with a water based or thoroughly cleaned rosin flux (not acid based) and made water proof.

Check for power, ground or continuity by disconnecting the connector and testing the individual pins or sockets in the connector.

probing.

connector identification. Individual wire identification will differ depending upon the type of connectors in use, the vehicle manufacturer, and the system features in use.

connections are present on all EC-17™ controllers, they are not always used.

PREVENTIVE MAINTENANCE

Every 3 months; 25,000 miles; or 900 operating hours;

1. Check all wiring and connectors to ensure they are secure and free from visible damage.

2. Although the EC-17™ controller incorporates self check diagnostics, the optional LED display should be inspected to ensure that it is functional. With the vehicle ignition on, a magnet (800 gauss; capable of picking up 3 ounces) held to the LED reset switch (indicated on the housing) should cause all of the LEDs to illuminate. If one or more of the LEDs DO NOT ILLUMINATE and the dash condition lamps indicate the system is functioning properly, the non-illuminated LED(s) should be noted for future reference. Although the diagnostic capabilities will be limited, the system will continue to function as designed.

3. Road test the vehicle by making an antilock stop from a vehicle speed of 20 miles per hour. When an antilock

stop is made, the modulator solenoids pulsate and an audible burst of air can be heard from outside of the cab. The wheels should not enter a prolonged "lock" condition. Also, make a traction acceleration by accelerating on a road surface with reduced traction. As with antilock, audible bursts of air can be heard when the traction system is functioning.

4. EC-17™ controllers not equipped with an LED display require the use of separate diagnostic tools capable of using the S.A.E. J1587 diagnostic Link.

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following general precautions should be observed at all times.

1. Park the vehicle on a level surface, apply the

parking brakes, and always block the wheels. Always wear safety glasses.

2. Stop the engine and remove 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, be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components.

3. 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.

4. 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 an AD-IS air dryer system or a dryer reservoir module, be sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s

recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.

6. Never exceed manufacturer’s recommended

pressures.

7. 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.

8. Use only genuine Bendix® replacement parts,

components and kits. Replacement hardware, tubing, hose, fittings, etc. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems.

EXTREME CAUTION should

™

9. Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make certain all components and systems are restored

to their proper operating condition.

11. For vehicles with Antilock Traction Control (ATC), the ATC function must be disabled (A TC 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.

REMOVING THE EC-17™ CONTROLLER

EC-17™ CONTROLLER MOUNTED ON ANTILOCK RELAY VALVE OR ANTILOCK TRACTION RELA Y VALVE

1. Remove as much contamination as possible from the

assembly's exterior. Keep the contamination away from the open ports and electrical connections.

2. Identify and remove all air lines connected to the unit.

3. Disconnect the electrical connector(s) from the EC-17

controller.

4. Note and mark the mounting position of the assembly

on the vehicle. Loosen, remove and save the nuts on the mounting hardware that attaches the controller relay assembly bracket to the vehicle. Remove the relay valve and EC-17™ controller from the vehicle.

5. Note and mark the position of the EC-17™ controller

relative to the valve it is mounted on. Remove and retain the four hex head bolts that secure the EC-17™ controller to the valve. Then separate the EC-17™ controller from the valve.

BRACKET MOUNTED EC-17™ CONTROLLER

1. Remove as much contamination as possible from the

assembly's exterior. Keep the contamination away from open air connections and electrical connections.

2. Disconnect the electrical connector(s) from the EC-17

controller.

3. Note and mark the mounting position of the EC-17

controller on the vehicle. Loosen, remove and save the nuts on the mounting hardware that attaches the EC-17™ controller bracket to the vehicle. Remove the EC-17™ controller and bracket from the vehicle.

4. Remove and retain the four hex head bolts that secure

the EC-17™ controller to the bracket. Separate the EC-17™ controller from the bracket.

INSTALLING THE EC-17™ CONTROLLER

EC-17™ CONTROLLER MOUNTED ON ANTILOCK RELAY VALVE OR ANTILOCK TRACTION RELA Y VALVE

1. After noting the relationship of the positioning marks made prior to disassembly, position and secure the EC-17™ controller to the valve using the four hex head bolts. Torque the hex head bolts to 98 Ibs. in. (Grade 5 bolts).

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2. Mount the assembled EC-17

controller and antilock relay valve on the vehicle and orient it in the position marked before removal.

3. Reconnect all air lines to the assembly.

4. Reconnect the electrical connector(s) to the EC-17 controller and torque the connector retaining screw (“jack screw”) to 15-20 inch pounds.

5. T est the valve for operation and leakage prior to placing the vehicle in service.

6. Perform the "Initial Start up Procedure" in the TROUBLESHOOTING section to assure proper system

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operation. (Appropriate for both EC-17

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& EC-17N

controllers).

BRACKET MOUNTED EC-17™ CONTROLLERS

1. Secure the EC-17™ controller to its bracket using the four hex head bolts. Torque to 98 Ibs. in (Grade 5 bolts).

2. After noting the positioning marks, mount the EC-17 controller on the vehicle using the mounting hardware retained during removal.

3. Reconnect the electrical connector(s) to the EC-17 controller and torque the connector retaining bolts to 15-20 inch pounds.

4. Perform the "Initial Start up Procedure" in the TROUBLESHOOTING section to assure proper system operation.

DIAGNOSING AND LOCATING A SYSTEM DIAGNOSTIC TROUBLE CODE

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GENERAL

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The EC-17™ controller contains self test and diagnostic circuitry that continuously checks for proper operation of the entire antilock/traction system, including wiring continuity . The EC-17™ & EC-17N™ controllers are programmed at the factory to accommodate the needs of the vehicle and the customer's desires. Both the EC-17™ & EC-17N™ controller can be reconfigured by the end user to include traction control (See the Important notice concerning the EC-17N™ controller). A vehicle equipped with traction control can generally be identified by noting the presence of a dash mounted condition lamp, a disable switch (for the traction control system) and a traction solenoid located above the relay valve.

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