Bendix EC-16 ANTILOCK CONTROLLER User Manual

Bendix® EC-16™ AntiLock - Traction Controller

SD-13-4787

MOUNTING

HOLES

(4)

18 PIN

CONNECTOR

FIGURE 1 - EC-16™ CONTROLLER

30 PIN

CONNECTOR

DIAGNOSTIC

DISPLAY

DESCRIPTION

GENERAL The EC-16™ 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-16™ controller can be assembled and programmed to provide an optional traction control feature. Figure 1 shows the basic EC-16™ controller configuration.

Designed to minimize the potential of brake lock up on all wheels during aggressive braking, the EC-16™ 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-16™ 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 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 .

There are two versions of the EC-16™ controller. The older version, was factory pre-programmed with vehicle particulars, such as the number of speed sensors, if the traction control feature was enabled and the type of traction control (torque limiting, differential braking or both). A part number was assigned to the EC-16™ controller which was specific for the programmed features contained in the unit. The newer version contains a self configuring or learning feature that allows the EC-16™ controller to be configured by the user when installed on the vehicle. Because of this feature, all of the new version EC-16™ controllers contain all the features and options available and will activate the specific features required for the vehicle it is installed on. The new version EC-16™ controller can be installed on vehicles with only antilock or vehicles using the traction control feature. The procedure for activating the self configuring feature and identifying old and new version EC-16™ controllers is

SPRING BRAKES

REAR AXLE SERVICE &

™

OR M-22

™

MODULATORS

M-21

TANDEM REAR AXLE

COMPUTER

DIAGNOSTIC

TRACTION LAMP

ANTILOCK

BATTERY

ENGINE ELECTRONIC

™

CONTROL MODULE

OR AT-2

™

TRACTION ASSEMBLY

AT-1

RETARDER DISABLE SWITCH

™

EC-16

CONTROLLER

QUICK

VALVE

RELEASE

VALVE

SERVICE BRAKE

SENSOR

WHEEL SPEED

SENSOR

EXCITER

WHEEL SPEED

EXCITER

ANTILOCK LAMP

TRACTION ENABLE SWITCH

FIGURE 2 - EC-16™ CONTROLLER SYSTEM SCHEMATIC

™

OR M-22

™

MODULATORS

M-21

contained in the section entitled "Configuring The EC-16 Controller".

In order to provide full vehicle wheel control antilock, the EC-16™ controller is used in combination with the following components:

- Four wheel speed sensors

- Four air pressure modulator valves

- One dash mounted antilock condition lamp

- One service brake relay valve

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

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CONTROLLER

ANTILOCK TRACTION

ASSEMBLY

™

EC-16

2-PIN CONNECTOR

(TO TRACTION SOLENOID)

- One traction solenoid (incorporated into the relay valve)

- Two additional wheel speed sensors (optional for tandem drive vehicles with differential braking feature)

- 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-16™ controller electronics are contained in a die cast aluminum housing and are environmentally protected by a self healing silicone compound. The metal housing and the design of the digital electronics are intended to provide a high degree of protection from radio and electromagnetic interference.

The patented light emitting diode (LED) display and a 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, connect the EC-16 controller to antilock and traction system components: one 30 pin and one 18 pin Packard Electric 150 series "Metri pack" connector. In addition to these two housing mounted connectors, the EC-16™ controller also uses a 2 pin Deutsch connector when programmed with the optional traction control feature. The 2 pin connector is linked to a traction solenoid, which is located in the upper portion of the antilock traction relay valve assembly . (See Figure 3.)

MOUNTING

TRACTION

RELAY

FIGURE 3 - EC-16™ CONTROLLER W/ANTILOCK TRACTION RELAY VALVE

The other EC-16™ controller is designed to be mounted on one of four different valves. All of the valves provide the relay function and replace the standard service relay on antilock equipped vehicles. In some instances the valves also provide specialized functions. When the EC-16™ controller is mounted on any of these valves, the result is a final assembly with its own model designation. Refer to the chart and figure

AntiLock Added Function Vehicle Designation

Valve Provided Application (Valve + EC-16)

AR 1 None All CR 17 Controller Relay AR 2 Bobtail Brake Tractors Only CR 18 Controller Relay

Proportioning ATR-1 Traction All AT 1 AntiLock Traction ATR 2 Traction & Bobtail Tractors Only AT 2 AntiLock Traction

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Brake Proportioning

EC-16™ CONTROLLER INFORMATIONAL INPUTS AND COMMAND OUTPUTS

GENERAL

The EC-16™ controller receives information from several components in system and, based on these inputs, issues commands or delivers information. Some portions of the EC-16™ controller both receive and deliver commands and information. (See Figure 4.)

TRACTION SOLENOID

The EC-16™ 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.

INPUTS

- Wheel speed information is provided to the EC-16

controller via a wiring harness from individual wheel speed sensors at or in the vehicle wheels. Working with an exciter or tone ring, wheel speed sensors provide information to the

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F E D C B A

A1 GROUND

A2 GROUND

A3 GROUND

B1 BATTERY VOLTAGE

B2 ENGINE CONTROL SERIAL A

B3 ENGINE CONTROL SERIAL B

C1 RIGHT FRONT MOD. COMMON

C2 TRACTION LAMP

C3 AUXILIARY OUTPUT

D1 RIGHT FRONT MOD. HOLD

D2 NOT USED

D3 NOT USED

E1 RIGHT FRONT MOD. EXHAUST

E2 NOT USED

E3 WARNING LAMP

F1 LEFT FRONT MOD. EXHAUST

F2 TRACTION ENABLE SWITCH

F3 NOT USED

G1 LEFT FRONT MOD. HOLD

G2 DIAGNOSTIC SERIAL A

G3 DIAGNOSTIC SERIAL B

H1 LEFT FRONT MOD. COMMON

H2 RIGHT FRONT W. S. SIGNAL

H3 RIGHT FRONT W. S. RTN

J1 LEFT FRONT W. S. SIGNAL

J2 LEFT FRONT W. S. RTN

J3 CHASSIS GROUND

K1 RETARDER DISABLE

K2 BATTERY VOLTAGE

K J H G F E D C B A

K3 BATTERY VOLTAGE

A1 RIGHT REAR MOD. COMMON

A2 FUTURE RELAY GRD.

A3 AUXILIARY OUTPUT

B1 RIGHT REAR MOD. HOLD

B2 RIGHT MID W.S. SIGNAL

B3 RIGHT MID W.S. RTN

C1 RIGHT REAR MOD. EXHAUST

C2 LEFT MID W.S. SIGNAL

C3 LEFT MID W.S. RTN.

D1 LEFT REAR MOD. EXHAUST

D2 TRACTION SOLENOID SOURCE

D3 TRACTION SOLENOID GRD.

E1 LEFT REAR MOD. HOLD

E2 RIGHT REAR W. S. SIGNAL

E3 RIGHT REAR W. S. RTN

F1 LEFT REAR MOD. COMMON

F2 LEFT REAR W. S. SIGNAL

F3 LEFT REAR W. S. RTN

inset below

See Lamp Relay

inset below

See Retarder Relay

M-22

AT-1, 2 ANTILOCK

TRACTION

MODULATOR AND

CONTROLLER

M-22

MODULATOR

CONNECTOR ON M-22

Switch

Retarder

Relay

Dash

Battery

Lamp

Battery

AntiLock

Controller

Relay

AntiLock

Controller

Retarder

Retarder Relay

Lamp Relay

M-22 Modulator

FIGURE 4 - EC-16™ CONTROLLER SYSTEM WIRING SCHEMATIC

M-22

WS-20™ STRAIGHT

SPEED SENSOR

ELECTRICAL

CONNECTOR

DELIVERY

PORT

EXHAUST

PORT

™

M-22

MODULATOR

SUPPLY

PORT

SUPPLY

PORT

MODULATOR

M-21

™

DELIVERY

PORT

WS-20™ 90

DEGREE SPEED

SENSOR

FIGURE 5 - WS-20

™

SPEED SENSORS

EC-16™ 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-16™ controller is designed to receive wheel speed information, from various wheel speed sensor models, at the rate of 100 pulses per wheel revolution. The EC-16™ controller is able to simultaneously receive, and individually interpret, speed signals from 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 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-16™ controller from the ignition switch through a fuse or circuit breaker. (30 amp.) The electrical ground for the EC-16™ controller is the vehicle chassis.

- A connection for a traction enable switch is provided, but not always used. The switch allows traction to be turned on or off manually .

OUTPUTS

- Modulators, like the Bendix® M-21™ or M-22™ modulator,

are the means by which the EC-16™ 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-16™ antilock controller. Solenoid valves contained in the modulator provide the electrical interface between the EC-16™ controller electronics

ELECTRICAL

CONNECTOR

FIGURE 6 - MODULATORS

EXHAUST

PORT

and the air brake system. The EC-16™ controller is able to simultaneously and independently control four individual modulator assemblies.

- An antilock dash light and its electrical relay are connected to, and controlled by , the EC-16™ controller and serve as a means of advising the driver of the condition of the antilock system.

- A connection to the engine or transmission retarder and its relay is provided on the EC-16™ controller, which allows the EC-16™ controller to temporarily disable the retarder during certain modes of operation. While the EC-16 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-16™ controller can also disable the retarder

using the same J1922 protocol it uses to control the traction control, engine torque limiting feature. For this redundant retarder disable to function, the EC-16™ controller must be connected to the engine control module (as would be the case if the EC-16 controller is programmed for the traction control, torque limiting feature).

- The data link enables the EC-16™ controller to "report" its operating condition to a specialized, external computer in response to certain commands it receives. The EC-16 controller diagnostic data link hardware conforms to S.A.E. standard J1708. The protocol, or coded language used, conforms to S.A.E. standard J1587. There are two connections to the EC-16™ controller devoted to the data link. While connections are provided for this function, it is not always used. The data link is not essential for the EC-16™ controller to be functional.

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If the EC-16™ controller is programmed for traction control, it contains the following outputs:

- A connection to the engine's electronic control module allows the EC-16™ controller to reduce engine torque under certain circumstances.

- A traction dash light is connected to and controlled by

™

the EC-16

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

PHILOSOPHY

The Bendix® EC-16™ controller 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-16 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.

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-16™ 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-16 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 are energized and de energized by the EC-16™ 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 re application of air pressure to the brake actuator. The solenoids in each modulator are

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controlled independently by the EC-16™ controller. By opening and closing the solenoid valves in the appropriate modulator, the EC-16™ controller is actually simulating what drivers do when they "pump the brakes". It must be remembered however that unlike the driver, the EC-16 controller is able to "pump" each brake on the vehicle independently and with far greater speed and accuracy .

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While each steering axle brake is under the control of an individual modulator, the EC-16™ controller does not treat these brakes totally independently . The EC-16™ 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-16™ 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.

OPERATION - TRACTION CONTROL

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 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 new version EC-16™ 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-16™ 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 feature to be used, the vehicle must be equipped with an antilock traction relay valve such as the Bendix® A TR-1™ or ATR-2™ relay valve. The ATR-1™ and ATR-2™ relay valve contain a solenoid assembly which provides this feature. The differential braking feature allows the EC-16

™

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 slipperiest surface), a slight brake application to this wheel only, forces the differential to drive the stationary or slowly spinning wheel. While a vehicle must be equipped with an electronic throttle to utilize the torque limiting feature of traction control, differential braking can be used on all vehicles. 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 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-16™ 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-16™ 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-16™ 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-16™ 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.

TRACTION CONTROL AT VEHICLE SPEEDS ABOVE 25 MPH

If wheel spin occurs at any speed above 25 mph, the

™

EC-16

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-16

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.

THE EC-16™ CONTROLLER WILL NOT SIGNAL THE A TR VALVE TO APPLY THE BRAKES, EVEN SLIGHTLY, AT ANY SPEED ABOVE 25 MPH.

ANTILOCK AND TRACTION SYSTEM OPERATION DURING COMPONENT FAILURE

The Bendix® EC-16™ 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-16

™

controller control.

Depending upon the type of failure and its position of occurrence, the EC-16™ 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 braking on all wheels.

SINGLE FAILURE

The following list and chart describe 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, and, as always, the system has 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. The traction system is disabled.

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Mid or rear sensor - Antilock on that wheel is disabled, but antilock on all other wheels remains active. 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.

Engine Control Module* - If the engine control module (ECM) or the wiring from the EC-16™ 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.

*Note: A voltage problem and an intermittent ECM wiring

problem can "correct" themselves. For example, a power surge can take the system out of voltage range for a moment, which will flash the voltage LED and an intermittent wiring problem between the EC-16™ controller and the ECM can cause the traction LED to go on. During the time that the problem is occurring, the dash lamp will also be on. When the problem corrects itself, the system is restored. The dash lamp and the appropriate LED go out.

For all other problems, the system will not be restored in the problem area until the error is corrected and the EC-16 controller is cleared with the reset switch. It should be remembered that the driver will be advised of the degraded operation via the dash lamps and that standard air braking will still be available on those brakes where the EC-16 controller has disabled the system.

MULTIPLE FAILURES

In the event that multiple failures occur, the dash lamp will react as it normally would during a single failure, and the LEDs will show one failure at a time. When the first problem is fixed and the system is reset, the next problem area will appear at the LEDs. This way , the driver or mechanic does not lose track of problem areas, and the system is not restored until each and every error is corrected and the EC-16™ controller is reset.

SYSTEM STILL OPERA TING (YES/NO)

ABS Front ABS Rear Traction Braking

Left Right Left Right

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 YES RR Sensor YES YES YES NO NO YES LR Sensor YES YES NO YES NO YES RF Modulator YES N O YES YES YES YES LF Modulator NO YE S YES YES YES YES RR Modulator YES YES YES NO N O YES LR Modulator YES YES NO YES N O YES Controller NO N O NO NO N O YES

FAILURE LOCATION

Solenoid YES YES YES YES NO YES Engine Control YES YES YES YES NO YES Module* Voltage* NO NO NO NO NO YES

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

ANTILOCK AND TRACTION WIRING

GENERAL NOTES

The wires that carry information and power into and out of the EC-16™ controller are generally grouped and terminate 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-16™ controller are illustrated in Figure 4. The wiring harnesses and connectors are weather resistant and the

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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

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general rules apply and should be followed where applicable:

1. It is generally advisable to replace a wire harness rather 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 rosin flux (not acid based) and made water proof.

2. Do not pierce wire insulation when checking for continuity. Check for power, ground or continuity by disconnecting the connector and testing the individual pins or sockets in the connector.

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

4. While the retarder disable, serial link, and traction on/ off connections (4 total) are present on all EC-16 controllers they are not always used.

Std.

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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.

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2. Although the EC-16

controller incorporates self check diagnostics, the 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 should cause all of the LEDs to illuminate. If one or more of the LEDs DO NOT ILLUMINA TE and the dash condition lamps indicate the system is functioning properly , the nonilluminated 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.

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, EXTREME CAUTION should 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.

DIAGNOSTIC

DISPLAY LEDs

FIGURE 7 - EC-16™ CONTROLLER DIAGNOSTIC DISPLA Y

RESET SWITCH

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 (ATC indication 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-16™ CONTROLLER

EC-16™ CONTROLLER MOUNTED ON ANTILOCK RELAY VALVE OR ANTILOCK TRACTION RELAY VALV E

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

2. Disconnect the electrical connector(s) from the EC-16

controller.

3. 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-16™ controller from the vehicle.

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4. Remove as much contamination as possible from the assembly's exterior. Keep the contamination away from the open ports.

5. Note and mark the position of the EC-16

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controller relative to the valve it is mounted on. Remove and retain the four cap screws that secure the EC-16™ controller to the valve. Then separate the EC-16™ controller from the valve.

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

DIAGNOSING AND LOCATING A SYSTEM PROBLEM

GENERAL

BRACKET MOUNTED EC-16™ CONTROLLER

1. Disconnect the electrical connector(s) from the EC-16 controller.

2. Note and mark the mounting position of the EC-16 controller on the vehicle. Loosen, remove and save the nuts on the mounting hardware that attaches the EC-16™ controller bracket to the vehicle. Remove the EC-16™ controller and bracket from the vehicle.

3. Remove and retain the four cap screws that secure the EC-16™ controller to the bracket. Separate the EC-16 controller from the bracket.

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

INSTALLING THE EC-16™ CONTROLLER

EC-16™ 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-16™ controller to the valve using the four cap screws. T orque the cap screws to 50-80 Ibs. in.

2. Mount the assembled EC-16™ 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-16 controller.

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 operation.

BRACKET MOUNTED EC-16™ CONTROLLER

1. Secure the EC-16™ controller to its bracket using the four cap screws. Torque to 50-80 Ibs. in.

2. After noting the positioning marks, mount the EC-16 controller on the vehicle using the mounting hardware retained during removal.

3. Connect the electrical connector(s) to the EC-16 controller.

The EC-16™ controller contains self test and diagnostic circuitry that continuously checks for proper operation of

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the entire antilock/traction system, including wiring continuity . The EC-16™ controller is programmed at the factory to

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accommodate the needs of the vehicle and the customer's desires. All EC-16

™

controllers are not factory programmed with the traction control feature, in which case antilock only will be active. The newer , self configuring EC-16™ controller can be reconfigured by the end user to include traction

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control. A vehicle equipped with traction control can generally be identified by noting the presence of a dashmounted condition lamp, a disable switch (for the traction control system) and a traction solenoid located above the relay valve.

Separate dash lamps, controlled by the EC-16™ controller, advise the driver of the condition of the entire antilock/traction system. The condition of specific components is provided by a series of labeled, light emitting diodes (LEDs) in the EC-16™ controller housing. No special tools or equipment are needed to read or interpret the EC-16™ controller diagnostic display. It should be noted that the EC-16 controller diagnostics display is separate from the antilock and traction condition lamps on the dash. With this separation, the driver is aware of any problems that occur but is not confused by diagnostic information.

When the controller senses an erroneous condition, it stores the condition in memory, disables the antilock or traction function, and illuminates the dash mounted condition lamp

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and the appropriate diagnostic LEDs on the EC-16 controller. The failure condition is truly stored and is not cleared by loss of power to the EC-16™ controller. The LEDs will relight when power is restored and remain illuminated until the failure is corrected. After the actual problem is corrected, maintenance personnel can clear or reset the EC-16™ controller diagnostics by holding a small magnet over the RESET point in the diagnostics display .

DIAGNOSTIC LEDS

There are ten LEDs plus a magnetically actuated reset switch

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in the EC-16™ controller diagnostic display . The first six LEDs locate a problem to a specific area of the vehicle, and the next three indicate the problem component or its wiring.

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The LEDs are software driven and are either ON or OFF depending upon their monitor function. (Note: right and left, front and rear are determined from the driver's seat.)

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