Troubleshooting guide

ManualsBrandsBENDIX ManualsComputer equipmentEC-60 ABS-ATC ESP CONTROLLERS ADV

For more information, visit www.bendix.com or www.foundationbrakes.com • 1-800-AIR-BRAKE (1-800-247-2725)

ABS Components, continued

• Dash-mounted tractor ABS Indicator Lamp

• Service brake relay valve

• Dash-mounted trailer ABS Indicator Lamp (used on all

towing vehicles manufactured after March 1, 2001)

• Optional blink code activation switch

• Optional ABS off-road switch. (Off-road feature is not

typically available on all models)

Some “Premium” Bendix ABS systems utilize additional

components, such as traction control valves, a dash-

mounted ATC status/indicator lamp, serial communication

to the engine control module, a stop lamp switch input

and optional ATC off-road switch.

With advanced ABS, the roll stability and ESP full stability

features require additional components, including vehicle

sensors to detect vehicle motion (lateral and yaw-rate

sensors, and pressure sensors for load estimation) and

driver intention (by monitoring the turning of the steering

wheel).

All Bendix ECUs feature digital electronics with self

test and diagnostic circuitry that continuously monitors

operation of the entire antilock system, including wiring

continuity. A history of all diagnostic trouble codes is

stored in the controller’s memory and is not cleared by

loss of power to the unit.

ECU controllers are typically available in frame-mounted

and cab-mounted models.

Bendix Wingman Adaptive Cruise & Braking (ACB) also

integrates some advanced ABS components to aid in

collision mitigation: see page 49 for more information.

Truck and Tractor ABS Operation

As described in the introduction to this section, Bendix

ABS uses wheel speed sensors, modulator valves and

an ECU. By monitoring individual wheel turning motion

during braking, the ECU is able to optimize slip between

the tire and the road surface by pumping the brakes on

individual wheels (or pairs of wheels), independently.

Steer Axle Control

Although both wheels of the steer axle have their own

wheel speed sensor and pressure modulator valve, the

ECU blends the applied braking force between the two

steering axle brakes. A Bendix patented brake application

control, called Modiﬁ ed Individual Regulation (MIR), has

been designed to help reduce steering wheel pull during

an ABS event on road surfaces with poor traction (or

areas of poor traction, e.g. asphalt road surfaces with

patches of ice).

Vehicle Conﬁ gurations

Depending on the number of drive axles, a variety of

number of sensors and modulators may be used for

an ABS system. For example, a 4 sensor/4 modulator

(4S/4M) system would typically be used for a single

drive axle vehicle. System conﬁ gurations are available

for 4S/4M, 6S/6M, and 6S/5M (with the additional

axle, a non-driven rear axle, having two sensors, but

only one pressure modulator valve). In the case of a

6S/5M arrangement, the PMV controls both wheels on

the additional axle. The additional axle wheels would

receive equal brake pressure, based on the wheel

that is currently experiencing the most wheel slip.

Bendix

EC-60

™

ABS/ATC Controllers

(left: Frame mount, and right: Cab Mount.)

Advanced Bendix

ABS

uses yaw and steering

wheel sensors to monitor

the vehicle motion.

See pages 40 and 41.

Speed Sensor

Mounting Block

100 Tooth (typical)

Speed Sensor

Exciter Ring

(“tone” ring)

Bendix

WS-24

™

Speed

Sensor

(90 Deg.)

Hub

Assembly

Foundation Drum

Brake

ABS Components Continued: Truck and Tractor ABS Operation

Bendix

EC-30

™

ABS/ATC

Controller