Bendix EC-13 TRAILER ANTILOCK CONTROL User Manual

Bendix® EC-13™ Trailer AntiLock Controller Assembly

SD-13-4783

MOUNTING HOLES (4)

DIAGNOSTIC

WINDOW

FIGURE 1 - EC-13™ TRAILER ANTILOCK CONTROLLER

EC-13™ Trailer AntiLock Controller

DESCRIPTION

GENERAL

Bendix trailer antilock systems utilizing the EC-13™ electronic controller assembly provide AXLE braking control for trailers. By controlling “wheel lock-up” during aggressive braking, the trailer retains a high degree of stability and steerability while braking, and vehicle stopping distance may be reduced.

In order to provide AXLE control antilock, the EC-13™ controller is used in combination with the following components;

- Four, individual wheel speed sensors

- Two M-12R™ remote mount modulator-relay valves or a combination of one M-12™ and one M-12R™ modulator

PHYSICAL

The EC-13™ controller assembly electronics, which regulate the function of the antilock system, are contained in a die cast aluminum housing and are environmentally protected by silicone encapsulation. The metal housing, coupled with the design of the digital electronics, is intended to provide a high degree of protection from radio and electromagnetic interference.

30 PIN WIRE HARNESS

CONNECTOR

A diagnostics display window with 9 light emitting diodes (LEDs) and a magnetically actuated reset switch is incorporated in the housing for troubleshooting and diagnostic purposes.

A single electrical connector is currently used on the EC-13™ controller, for connection to the antilock system components; a 30 pin, Packard Electric, 150 series “Metripack.”

MOUNTING

The EC-13™ controller can be remote bracket mounted to a frame member or can be mounted directly on a modulatorrelay valve assembly , such as the Bendix® M-12™ modulator (reference SD-13-4772). When the EC-13™ controller is mounted on a modulator assembly the resulting assembly receives a different designation. For example when the EC-13™ antilock controller is mounted on the M-12™ modulator the resulting assembly (i.e.; EC-13™ controller plus M-12™ modulator) is known as a MC-13™ modulator controller (see Figure 3). When the EC-13™ controller is bracket mounted to a frame member, and not mounted on the modulator, an M-12R™ modulator is used. The M-12R™ modulator is identical to the M-12™ modulator but has remote mounting capabilities (see Figure 6).

SPRING

BRAKE

™

WS-20

WHEEL SPEED SENSOR

™

M-12R

MODULATOR

EC-13

CONTROLLER

™

CONTROL (SERVICE) LINE

SUPPLY (EMERGENCY) LINE

™

SR-5

SPRING BRAKE VALVE

TO TRAILER ELECTRICAL

CONNECTOR

TRAILER ANTILOCK

WIRING HARNESS

FIGURE 2 - TYPICAL EC-13™ TRAILER ANTILOCK SYSTEM

SPRING BRAKE

EC-13™ CONTROLLER INFORMATION INPUTS AND COMMAND OUTPUTS

GENERAL

™

M-12R

MODULATOR

Reservoir

WS-20

WHEEL SPEED

SENSOR

30 PIN CONTROLLER

CONNECTOR

™

Reservoir

Vehicle power is supplied to the EC-13™ controller from the stop light switch. The electrical ground for the EC-13™ controller is from the 7 pin trailer connector and trailer chassis.

The EC-13™ 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-13™ controller both receive and deliver commands and information.

INPUTS

Wheel speed information is provided to the EC-13™ controller via a wiring harness from individual speed sensors located in the trailer wheels or axle housing. Working in conjunction with an exciter or tone ring, the speed sensors provide information to the EC-13™ 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-13™ 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-13 to simultaneously receive, and individually interpret, speed signals from four wheel speed sensors (2 axles).

™

controller is able

OUTPUTS

Modulators, like the Bendix® M-12™ and M-12R™ modulators, are the means by which the EC-13™ antilock controller is able to modify driver applied air pressure to the service brakes. The EC-13™ controller is able to simultaneously and independently control two modulators assemblies. The M-12™ and M-12R™ modulators are combination valves consisting of a standard relay valve and solenoid assembly. They replace the standard relay valves used to speed up the application and release of the trailer’s rear axle brakes. An external, three pin, wiring harness connects the EC-13™ controller to the M-12™ or M-12R™ modulator solenoid assembly. For additional information and service procedures see Bendix Service Data Sheet SD-13-4772.

As stated previously , the EC-13™ controller is designed to control two modulators. It can be mounted directly on an M-12™ modulator relay valve assembly and control a separate M-12R™ modulator or the EC-13™ controller can itself be remote mounted to the trailer and control two M-12R™ modulators. When mounted directly on a modulator, the two separate components (EC-13™ controller and M-12™ modulator) become a single assembly called the MC-13™ modulator controller.

EC-13™

Controller

™

M-12

Modulator

FIGURE 3 - TYPICAL MC-13™ MODULATOR CONTROLLER

™

(EC-13

CONTROLLER & M-12™ MODULATOR)

Connected to the EC-13™ controller via a wire harness, the modulator is essentially a high capacity , on/off air valve that incorporates a pair of electrical solenoids for control. The solenoids provide the electric-air link between the antilock controller electronics and the air brake system.

An optional indicator light can be connected to, and controlled by, the EC-13™ controller and serves as a means of advising the driver of the condition of the antilock system.

The data link function enables the EC-13™ controller to “report” its operating condition to a specialized, external computer in response to certain commands it receives. The EC-13™ controller data link conﬁ guration conforms to S.A.E. standard J1708 and the protocol, or coded language used, conforms to S.A.E. standard J1587. There are two connections to the EC-13™ controller devoted to the data link. While the EC-13™ controller is capable of this function, and connections are provided, it is not always used. Use of the data link is not essential for the EC-13™ controller

to be functional.

WS-20

™

Speed Sensor

Straight Conﬁ guration

OPERATION

OPERATIONAL PHILOSOPHY

The Bendix® EC-13™ controller provides axle braking control by using four speed sensors and two modulators. By monitoring the rate of deceleration during braking, and subsequently adjusting the brake application pressure to each axle, the EC-13 braking while maintaining trailer stability.

The trailer’s rear axle brakes are controlled by the EC-13 controller and two modulators (M-12™ or M-12R™). Like the standard service relay valve it replaces, the modulator delivers brake application pressure to the service chambers on each axle. Two speed sensors on each axle “report” changes in acceleration and deceleration to the EC-13™ controller. If required, the EC-13™ controller adjusts the application pressure to either axle’s service brakes, via the modulators, based on the wheel behavior “reported” to it by the speed sensors on each axle.

The EC-13™ controller utilizes a “SELECT SMART” brake control philosophy for the trailer brakes. This means that the EC-13™ controller will initially adjust application pressure to the service chambers on either an axle based on the speed information from the ﬁ rst wheel to approach a locked condition. The initial pressure adjustment will attempt to prevent either wheel on an axle from locking. If a substantial braking difference is detected between two wheels on an axle, the EC-13™ controller will override the ﬁ rst air pressure adjustment and allow one wheel to lock. Both wheels including the locked wheel will continue to be monitored for speed and braking difference changes that would require pressure adjustments. Each of the two axles is treated independent of the other.

NON-ANTILOCK BRAKE APPLICATION

During normal braking, the tractor brake valve simultaneously delivers air to the control port of the two trailer modulators. The modulators function the same as standard service relay valves and apply air to the service brakes. The service brakes are thus applied.

If the speed sensors do not detect an impending wheel lock up, the EC-13 corrective action and the trailer comes to a stop in a normal fashion.

™

controller is able to provide improved

™

controller does not initiate any

™

WS-20™ Speed Sensor

90 Degree

Conﬁ guration

FIGURE 4 - WS-20™ WHEEL SPEED SENSORS

ANTILOCK CONTROLLED BRAKE APPLICATION - SYSTEM FULLY OPERATIONAL

If a service brake application is made and the speed sensors detect an impending wheel lockup on an axle, the EC-13™ controller will immediately begin modiﬁ cation of the brake application using the antilock modulators at the affected axle(s).

Solenoid valves contained in the modulator are energized and de-energized by the EC-13™ controller in order to modify the brake application. When a solenoid coil is energized its shuttle moves, and depending upon the function of the speciﬁ c solenoid, it either opens or closes, thereby causing the exhaust or re-application of air pressure to the relay valve portion of the modulator and to

With the failed component approach described, the antilock system will attempt to provide the trailer with the best possible braking and stability even after a problem has occurred. It should be remembered that the driver will be advised of any degraded antilock operation via the condition lamp and that standard air braking will still be available on those brakes where the antilock has been disabled.

the brake actuators connected. The solenoids in either the

™

or M-12R™ modulator are controlled independently

M-12

ANTILOCK WIRING

by the EC-13™ controller. By opening and closing the solenoid valves in the appropriate modulator, the EC-13™ controller is actually simulating what the driver does when he “pumps” the brakes.

It must be remembered however that unlike the driver, the EC-13™ controller is able to “pump” brakes on either the front or rear axle(s), or both, independently and with far greater speed and accuracy.

GENERAL NOTES

The wires that carry information and power into and out of the EC-13™ controller are grouped and terminate at a 30 pin Packard connector which plugs into the EC-13™ controller. The wiring harnesses and connectors are weather proof and the wires that enter the connector are sealed to the connector. The wire gauge used in the wire harnesses is speciﬁ c to the task performed.

ANTILOCK SYSTEM OPERATION COMPONENT PROBLEM

The Bendix® EC-13™ controller handles equipment problems using a conservative fail-safe philosophy. Any single electrical problem in a component devoted to antilock braking, results in simultaneous illumination of the antilock condition lamp and a troubleshooting LED on the EC-13™ controller. Depending upon the type of problem and its position of occurrence the EC-13™ controller can continue antilock function at a lower performance level, disable all of the antilock on the trailer or only a portion. When antilock is disabled, the brakes on the affected axle(s) revert to standard air braking.

System Parts Still Operating ( Yes / No )

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

3. Always check the vehicle hand book for wire and

Problem ABS Lead ABS Rear Location Axle Axle

Lead Axle Rt. Sensor Yes Yes Lead Axle Lft. Sensor Yes Yes Rear Axle Rt. Sensor Yes Yes Rear Axle Lft. Sensor Yes Yes Lead Axle Modulator No Y es Rear Axle Modulator Y es No Controller No No Voltage * No No

* If electrical power is below or above the 7 to 18 volt operating range the ABS will stop operating. If voltage returns to the 8-17

volt range the ABS is restored.

A problem in a single speed sensor will not result in disabling of the antilock system. If a speed sensor problem is detected by the EC-13™ controller, the remaining speed sensor on the axle will be used to continue antilock operation on the axle but at a slightly degraded level of performance.

4. While the serial link connections (2 total) are present

PREVENTATIVE MAINTENANCE

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

1. Check all wiring and connectors to ensure they are

2. Although the EC-13™ controller incorporates a self

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 ﬂ ux (not acid based) and the splice made water proof.

continuity. Check for power, ground or continuity by disconnecting the connector and testing the individual pins or sockets in the connector(s). Do not overstress sockets.

connector identiﬁ cation. Individual wire identiﬁ cation will differ depending upon the type of connectors in use, the trailer manufacturer, and the system features in use.

on all EC-13™ controllers they are not always used. In addition several connector openings are not used.

secure and free from visible damage.

check diagnostics, the LED display should be inspected to ensure that they are functional. With the tractor ignition on and a brake application held applied, hold a magnet (800 gauss; capable of picking up 3 ounces) on the diagnostic window reset switch and note all of the LEDs illuminate. If one or more of the LEDs DO NOT ILLUMINATE and the antilock condition lamp on the trailer indicates 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.

™

M-12R

Modulator

Trailer Wiring

Wheel Speed Sensor

™

Harness Connector

WS-20

™

M-12R

Modulator

Connector

Wheel Speed

(to Sensor)

Connector)

(to Trailer Electrical

Wire Harness Connector

Spring Brake

Modulator

Connector

(to Modulator)

Controller)

™

Connector

Trailer Wiring Harness

(Connects to EC-13

Note:

Connector terminals not listed in the chart

are currently not in use.

Status Light

Trailer AntiLock

Trailer Service Air Line

Terminal Connection

1K & 2K Battery Power (+) Stop Light Switch

1A & 2A Trailer Ground

3F Trailer Status Lamp

1G Front Modulator Common

2G Front Modulator Hold

2F Front Modulator Exhaust

1D Rear Modulator Common

1C Rear Modulator Hold

Connector

Trailer Electrical

GROUND

(WHT)

TAIL

LIGHTS

(BRN)

RIGHT

TURN

LIGHTS

(GRN)

POWER

(BLUE)

(RED)

BRAKE

Connector

Trailer Electrical

(BLK)

MAKER

LIGHTS

FIGURE 5 - TYPICAL MC-13™ MODULATOR CONTROLLER TRAILER WIRING SCHEMATIC

LIGHTS

LEFT TURN

(YLW)

T erminal Allocation

Typical Trailer Connector

1B Rear Modulator Exhaust

3J Left Front Wheel Speed Signal

3H Left Front Wheel Speed Signal

2H Right Front Wheel Speed Signal

3K Right Front Wheel Speed Signal

3E Left Rear Wheel Speed Signal

2C Left Rear Wheel Speed Signal

3D Right Rear Wheel Speed Signal

3C Right Rear Wheel Speed Signal

3A Serial A

3B Serial B

EC-13™

Controller

™

M-12R

Modulator

(Remote

Mount)

FIGURE 6 - EC-13™ CONTROLLER AND M-12R™ MODULA TOR ASSEMBLY

3. Road test the trailer 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. The wheels should not enter a prolonged “lock” condition.

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO A VOID 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, ﬁ ttings, etc. must be of equivalent size, type and strength as original equipment and be designed speciﬁ cally for such applications and systems.

9. 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.

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 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 EC-13™ CONTROLLER ASSY

Locate the EC-13™ controller on the trailer and determine if it is mounted on a modulator (e.g. M-12™ modulator) or is remote mounted to a trailer frame member using a bracket. Use the appropriate removal procedure below.

Removing the EC-13™ Controller and M-12™ Modulator:

1. Identify and remove all air lines connected to the

M-12™ modulator.

2. Disconnect the electrical connector (on the vehicle

wiring harness) from the EC-13™ controller.

3. Note and mark the mounting position of the MC-13™

modulator - controller assembly on the trailer. Loosen, remove and save the nuts on the mounting hardware that attaches the MC-13™ modulator controller bracket to the trailer. Remove the MC-13™ modulator - controller assembly from the trailer.

4. Remove as much contamination as possible from

the exterior of the assembly making sure to keep the contamination away from the open ports.

5. Note and mark the position of the EC-13™ controller

relative to the M-12™ modulator. Remove and retain the four hex cap screws that secure the EC-13™ controller to the M-12™ modulator. Carefully separate the EC-13™ controller from the M-12™ modulator enough to expose the wire harness that connects both units electrically. Disconnect the wire harness by separating the four pin connector at the EC-13™ controller. Peel the gasket from the EC-13™ controller or M-12™ modulator and retain for reuse. Note: Use a new gasket if damaged during removal or if a new gasket is immediately available.

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