BENDIX EC-17 ANTILOCK TRACTION CONTROL User manual

1
®
SD-13-4788
DESCRIPTION
GENERAL
TheEC-17™isanelectronicantilockcontroller.Itisthebase
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
assembledandprogrammedto provide an optionaltraction
controlfeature.Figure1 shows the basicEC-17™/EC-17N™
controllerconfigurations.
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
minimizeswheelskidduringhardor aggressive braking. By
controllingwheelskid at allwheels on thevehicle,optimum
steeringcontrol and stopping distance is obtained.
Tractioncontrol,anoptional feature in thefullvehicle wheel
controlantilocksystem,helpsimprovevehicletractionduring
acceleration in adverse road conditions. Integrated with
antilock logic, traction control monitors wheel speed
informationfromthesensorsduringacceleration,aswell as
braking. The system helps maintain vehicle stability on
hazardousroadsurfacesandimprovesdriveabilityandsafety.
TheEC-17™controllercontainsaself configuring orlearning
feature that allows it to be configured by the user when
installedonthe vehicle. Becauseofthis feature, allEC-17™
controllerscontainallthefeaturesand options available and
willactivatethespecificfeaturesrequired 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
“ConfiguringTheEC-17™Controller”.
In order to provide full vehicle wheel control antilock, the
EC-17™controlleris used in combination withthe following
components:
- Four or six wheel speed sensors
- Fourairpressuremodulatorvalves
- Onedash mounted antilock condition lamp
- Oneservicebrakerelayvalve
MOUNTING
HOLES
(4)
Bendix®EC-17™AntiLock - Traction Controller
18 PIN
CONNECTOR 30 PIN
CONNECTOR
DIAGNOSTIC
DISPLAY
FIGURE 1 - EC-17™& EC-17N™ANTILOCK TRACTION CONTROLLERS
EC-17N™CONTROLLER
WITHOUT LED DIAGNOSTICS
EC-17™CONTROLLER
WITH LED DIAGNOSTICS

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FIGURE 2 - EC-17™ANTILOCK TRACTION CONTROLLER SYSTEM SCHEMATIC
TRACTION ENABLE SWITCH
ANTILOCK LAMP
RETARDER DISABLE SWITCH BATTERY
ENGINE
ELECTRONIC
CONTROL MODULE
M-21™OR M-22™
MODULATORS
QUICK
RELEASE
VALVE
SERVICE BRAKE
VALVE
EC-17™
CONTROLLER
AT-1™ORAT-2™
ANTILOCK TRACTION
ASSEMBLY
M-21™OR M-22™
MODULATORS
TANDEM REAR AXLE
WHEEL SPEED
SENSOR EXCITER
WHEEL SPEED
SENSOR
EXCITER
REAR AXLE SERVICE &
SPRING BRAKES
DIAGNOSTIC
COMPUTER
TRACTION LAMP

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Whenprogrammedto provide tractioncontrol in additionto
antilock,the following componentsare added:
- Onetractionsolenoid(incorporatedinto the relay valve)
- Onedash mounted tractioncondition lamp
- Serialconnectiontoenginecontrol module (for vehicles
programmed for torque limiting feature)
- Traction disable wiring and switch
PHYSICAL
The EC-17™controller electronics are contained in a non-
metallic 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,
electromagneticandenvironmentalinterference.
Thepatentedoptionallightemittingdiode(LED)displayand
magnetically actuated reset switch is incorporated in the
housingfortroubleshooting and diagnostic purposes.
Twoelectricalconnectors,located in thecontroller 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
solenoidis locatedintheupperportionoftheantilocktraction
relayvalveassembly.(SeeFigure3.)
MOUNTING
TheEC-17™controllerisavailablein two different mounting
styles. One model, shown in Figure 1, is a stand-alone. It
isintended for bracket mounting to a frame member and is
notattached to an antilock relay valve.
The other EC-17™controller is designed to be mounted on
oneoffour differentvalves.Allofthe valves provide therelay
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™controller both receive and deliver
commandsandinformation. (See Figure5.)
INPUTS
- Wheel speed information is provided to the EC-17™
controllervia a wiring harness fromindividual wheel speed
sensorsat the vehiclewheels (See Figure4). Working with
an exciter or tone ring, wheel speed sensors provide
information to the EC-17™controller in the form of an AC
signalwhichvariesinvoltageandfrequency as the speed of
thewheelincreasesordecreases. The EC-17™controller is
designedto receive wheelspeed information, fromvarious
wheel speed sensor models, at the rate of 100 pulses (86
pulses if so configured) per wheel revolution. The EC-17™
controllerisableto simultaneously receive, and individually
interpret,speedsignalsfromuptosixwheelspeedsensors.
Vehicledrive configurationand whether thetraction 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
antilockandtraction operation.Avehiclewith two rear drive
2-PIN
CONNECTOR
(TO TRACTION
SOLENOID)
ANTILOCK TRACTION
ASSEMBLY EC-17™
CONTROLLER
TRACTION
SOLENOID
(INHOUSING)
TRACTION
RELAY
FIGURE 3 - EC-17™CONTROLLER W/ANTILOCK
TRACTION RELAY VALVE
AntiLock Added Function Vehicle Designation (Valve +
Valve Provided Application EC-17™Controller)
AR-1™None All CR-17™Controller Relay
AR-2™Bobtail Brake Tractors Only CR-18™ControllerRelay
Proportioning
ATR-1™Traction All AT-1™AntiLock Traction
ATR-2™Traction & Bobtail Tractors Only AT-2™AntiLock Traction
Brake Proportioning
functionand replace the standard service relay on antilock
equippedvehicles.Insomeinstancesthevalvesalsoprovide
specialized functions. When the EC-17™controller is
mountedonanyofthesevalves,theresultisafinalassembly
with its own model designation. Refer to the chart below
andFigure3.
FIGURE 4 - WS-20™AND WS-24™WHEEL SPEED
SENSORS
90°SPEED
SENSORS
STRAIGHTSPEED
SENSORS
WS-24™
SENSOR
WS-20™
SENSOR
WS-20™
SENSOR
WS-24™
SENSOR

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FIGURE 5 - EC-17™ANTILOCK TRACTION CONTROLLER SYSTEM WIRING SCHEMATIC
Note:M-21™and M-22™modulators are shown in the diagrams in this document — newer model M-30™, M-32™andor M-32QR™modulators are used on many vehicles. Earlier modulators (M-21™, M-22™, or M-30™) may be replaced by M-32™ or M-32QR™modulators - except for front axle use where there is not a quick release valve (e.g. a Bendix QR-1™ quick release valve) and then only M-32QR™ modulators are permissible. We do not recommend replacing M-32™or M-32QR™modulators with earlier modulators.
Note: WS-20™wheel
speed sensors are shown in this document — newer model WS-24™
wheel speed sensors are used on many vehicles. WS-24™wheel
speed sensors may be used to replace WS-20™
wheel speed sensors. We do not recommend replacing WS-24™wheel
speed sensors with WS-20™wheel speed
sensors.

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axles (6 x 4) requires 4 speed sensors for antilock only
operation, but have the option to use 6 speed sensors for
enhancedperformanceofbothantilockandtractionoperation.
- Vehicle power is supplied to the EC-17™controller from
the ignition switch through a 30 amp fuse. The electrical
groundfor theEC-17™controller isthe vehiclechassis.
- 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.
- ATCrequiresJ1922/J1939driversrequestedtorque. This
input is necessary to engage differential braking on units
builtaftermid-year 2000.
OUTPUTS
- Modulators -TheBendix®M-22™modulator,isthemeans
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. Awiring harness
connects the modulator to the EC-17™antilock controller.
Solenoid valves contained in the modulator provide the
electricalinterfacebetweentheEC-17™controllerelectronics
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
theEC-17™controller,amodulator“chuff”test is performed.
WhenthebrakepedalisdepressedandtheECUispowered
viatheignitionswitch,thepatentedmodulator“Chuff”testis
audible. Aproperly 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
energizedthreetimeslonger than anexhaustsolenoidwhile
the“Chuff”testisbeingexecuted. Ifthe 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. Ifthemodulator hold andexhaust solenoid wiresare
reversedthe modulator will exhaust twice during a “Chuff”.
The vehicle modulators will “Chuff” in the sequence: right
front,leftfront,rightrear,leftrear. Itwillexecutethisexhaust
sequencetwice,foratotalofeightexhausts. Bothpatented
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
withthe modulators,proceedwithmodulatortroubleshooting
or compare the modulator wiring to the vehicle wiring
schematic found in Figure 5.
- An AntiLock dash light through an electrical relay is
connectedto, and controlled by,the EC-17™controller and
servesas a means of advisingthe driver of the conditionof
the antilock system.
-Twocontrollink connectionstotheengineortransmission
retarder anditsrelay are provided on the EC-17™controller.
Onecontrol link orthe other canbe utilized, butnot both on
thesamevehicle.Thehardwareforonecontrollinkconforms
toS.A.E. standard1708andtheprotocol, orcodedlanguage
used,conformstoS.A.E.standardJ1922.Theothercontrol
link conforms to S.A.E. standard J1939. Use of a control
linkallows the EC-17™controller to temporarily disable the
retarderduringcertain modes ofoperation. Unitsbuilt after
mid-year2000 haveimproved retarderoperation, allowing
the retarder to re-enable sooner following an ABS event.
Whilethe EC-17™controller iscapable ofthis function, and
connections are provided, it is not always used. Use of the
retarder disable function is not essential but highly
recommendedforvehiclesequippedwitha retarder.
Note: TheEC-17™controllercanalsodisabletheretarder
using the same S.A.E. J1922 or S.A.E. J1939
protocolit usestocontrolthetraction control,engine
torquelimiting feature. For this redundant retarder
disable to function, the EC-17™controller must be
connected to the engine control module (as would
bethecaseiftheEC-17™controllerisprogrammed
for the traction control, torque limiting feature).
- The diagnostic link enables the EC-17™controller to
"report"itsoperating conditiontoanexternalcomputerusing
theBendix diagnostic communications interface hardware
inresponse to certain commands itreceives from software
like Bendix ACom®for Windows*. The EC-17™controller
diagnosticlink hardwareconformstoS.A.E.standardJ1708.
Theprotocol, 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.
FIGURE 6 - M-30™, M-32™, AND M-32QR™MODULATORS
* Windows is a registered trademark of Microsoft Corporation.
M-32QR™
MODULATOR
M-32™
MODULATOR
ELECTRICAL
CONNECTOR
DELIVERY
(PORT2)
SUPPLY
(PORT1)
EXHAUST
(PORT3)
M-30™
MODULATOR

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Ifthe EC-17™controller is programmed for tractioncontrol,
it contains the following outputs:
- Aconnection to theengine's electronic control module
allowstheEC-17™controller to reduce enginetorqueunder
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
upperportionofthe antilock traction relayvalve(see Figure
3) is provided via a 2 pin Deutsch connector.
OPERATION - ANTILOCK (ABS)
PHILOSOPHY
The Bendix®EC-17™antilock system uses individual
sensors,modulators andan electronic controller to control
thefourvehiclewheel ends. By monitoringthedeceleration
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.
Therearaxlebrakes are controlledindependently;therefore
brakeapplicationpressureat an individual wheelisadjusted
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
thesebrakes independently.TheEC-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 eventeach wheel istraveling on a different road
surface(forexample,iceclosetothecurb and a dry crown).
EssentiallytheEC-17™controllercontrols the brakingforce
differencesbetweenthe 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,
andanother modulator controlsboth brakeson the driver's
sideofthetandem.Withthisarrangementofspeedsensors
andmodulators,both brakes on oneside of the tandemare
treated as one since they will most likely be on the same
typeof road surface.
NON ANTILOCK BRAKE APPLICATION
During normal braking, air pressure from the brake valve
entersthecontrolportofthe service relay valve. The service
relay delivers air to, and through, the antilock modulator
locatednearthe braked wheel,and into the brakeactuator.
Theservicebrakesarethusapplied.If the wheel sensors do
notdetectanimpendingwheellockup,theEC-17™controller
doesnotinitiateany corrective action and thevehiclecomes
to a stop in a normal fashion.
ANTILOCK BRAKE APPLICATION
Ifa service brake application is made andthe 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 containedin 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.
Dependingupon thefunctionofthespecificsolenoid,iteither
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"
eachbrakeon thevehicleindependentlyandwithfargreater
speedand accuracy.
OPERATION - TRACTION CONTROL (ATC)
PHILOSOPHY
Traction control is a natural extension of antilock. Just as
antilock helps vehicle control and stability during braking,
tractioncontrolhelpsduringvehicle 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
spinningwheelis instantly detectedandcompared with the
otherwheelsonthevehicle,bothfrontandrear. Twomethods
areusedto controlwheelspin,torquelimitingand differential
braking. Bothmethodscould be configured withinthe ECU
independentlyortogether. Onunitsmanufacturedaftermid-
year 2000, only torque limiting can be configured
independently. On unitsmanufactured aftermid-year2000
it will also be necessary that the J1922 or J1939 serial link
protocol communicate the vehicle throttle position or the
ATC willnot function.
Withtraction control, aspinning wheel is instantly detected
and compared with the other wheels on the vehicle, both
front and rear. Two different methods are used to control
wheelspin;torquelimitinganddifferentialbraking.Depending
uponvehicletype,speedandroad(surface)condition, each

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modulators. Because the modulators are controlled by the
EC-17™controller, the solenoid valves in the appropriate
modulatorareopened and closed togentlypump the brake
on the spinning wheel only. This gentle brake application
forcesthedifferentialtodrivethestationaryorslowlyspinning
wheel.
Oncewheel spin is eliminated,the dash lampgoes out and
the traction system disengages control.
Inthe event thatextended periods of traction operationare
experienced, without vehicle motion being detected, the
ABS traction system will disable traction control to prevent
brakefade. The system willre-enable traction controlafter
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™controllerwill instantly blink the tractiondash lamp
toadvise 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
sendsasignaltoreduceenginetorquetoalevelsuitablefor
theavailabletraction.
NOTE:THEEC-17™CONTROLLERWILLNOTSIGNALTHE
ATR™VALVETOAPPLYTHE BRAKES,EVEN SLIGHTLY,
ATANY SPEEDABOVE 25 MPH.
ANTILOCK AND TRACTION SYSTEM
OPERATION DURING COMPONENT FAILURE
The Bendix®EC-17™controller handles equipment failure
usingaconservativefailsafephilosophy.Anysingleelectrical
failureofacomponentdevotedtoantilockortractioncontrol
results in simultaneous illumination of the appropriate
condition lamp on the dash, a disabling of part or all of the
antilockortractionsystem,andreversiontostandardbraking
onwheelsno longer underEC-17™controllercontrol.
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.
Thereareavarietyofwaystoclear diagnostic trouble codes
detected by the system. In most cases, the system will
resetthediagnostictroublecodeconditionwhenthesource
of the original diagnostic trouble code has returned to a
normalstatefora period of time.Isolateddiagnostic trouble
codes are able to be reset by the system, but repeated
occurrence (and self-clearing) of some diagnostic trouble
codeswill require amanual reset. This isdone to aid in the
troubleshootingof intermittentdiagnostictroublecodes. The
PCinterface(or optionalmagneticreset)isusedtomanually
cleardiagnostic trouble codes.
methodprovidesa unique anddesirable type ofwheel spin
control. Ideally both methods are used to control vehicle
traction.WhileallEC-17™controllersarecapableofproviding
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
configurationprocedure.
TorqueLimiting-Inorderforthetorquelimitingcontrolfeature
to be used, the vehicle must be equipped with an
electronicallycontrolled engine throttle.The torque limiting
featureallowstheEC-17™controller toreduceenginetorque
to a suitable level for the available traction.Torque limiting
helpsto minimize the amount (orspeed) of wheel spin. Itis
especiallyusefulin helping tominimizing a powerjackknife
andwhenalldrivewheelsareonan equallyslipperysurface.
DifferentialBraking-Inorderforthedifferentialbrakingcontrol
to be used, the vehicle must be equipped with an antilock
tractionrelayvalve such as theBendix®ATR-1™orATR-2™.
Additionally after mid-year 2000 the ECU requires J1922/
J1939drivers torquerequest. TheATR-1™andATR-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.
Sincethe vehicle's differential tends todrive the wheel that
presentstheleast resistance(thewheelonthemost slippery
surface),aslightbrake application to thiswheelonly,forces
thedifferentialtodrivethestationaryorslowlyspinningwheel.
Differentialbrakingcanbeactivatedonlywhenvehiclespeed
isunder25MPHandonedrivewheelisspinningfasterthan
theother(s).
TractionEnable/Disable Switch-Thetractioncontrolenable/
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
howeverthat while thetraction control will disengage while
the vehicle is in motion it will not re-engage (even with the
switchin the engagedposition) until thevehicle comes to a
complete stop.
TRACTION CONTROL AT VEHICLE SPEEDS
OF 0 TO 25 MPH
Whenwheel spin isdetected andthe vehicle isstopped, or
moving at any speed up to 25 mph, the EC-17™controller
simultaneouslyexecutes the followingoperations:
Itinstantlyblinks the tractiondash lamp toadvise the driver
that a wheel spin is occurring.
Ifthe torque limitingfeature is active,the EC-17™controller
usesitslinktotheenginecontrolmoduleandsendsasignal
toreduce enginetorque to a level suitable for the available
traction.
Ifthedifferentialbrakingfeatureisconfiguredintothesystem,
the EC-17™controller energizes the solenoid in the ATR
valve which then applies air to each of the rear axle

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AUTO CALIBRATION
For optional ATC performance the ECU utilizes a feature
referred to as auto calibration. Auto calibration allows the
ECUtocompensateforvarioustiresizes throughout the life
ofthe vehicle. As thereare many conditionsthat can result
intheappearanceof a change inthetire size, several items
mustbesatisfied beforetheautocalibrationfeatureis active.
Theautocalibrationfeaturewouldautomaticallychangethe
ECUs imbedded tire sizes if the difference exceeded
approximately8%. Ifissues occur withyourATCdue to tire
size changes please contact 1-800-AIR-BRAKE or
1-800-247-2725forassistance.
SINGLE FAILURE
The following list and chart describes how the antilock and
traction systems respond to a specific component failure.
(Note:rightandleft;front,midandrear are determined from
thedriver's seat. Leftfront is thereforethe corner closestto
thedriver.)
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
remainsactive.
Rearmodulator-Arearmodulatorfailuredisablesthetraction
system. Antilock on that wheel will also be disabled, but
antilockon all other wheels remains active.
Frontsensor- The wheelis still modulatedusinginput 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
remainsactive.
EngineControlModule-Iftheenginecontrolmodule(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
diagnostictrouble code at a time.When thefirst diagnostic
trouble code is fixed and the system is reset, the next
diagnostic trouble code area will appear at the LEDs. This
way,thedriverormechanicdoesnotlosetrackofdiagnostic
trouble code areas, and the system is not restored until
eachandeveryerroriscorrected and the EC-17™controller
is cleared of all diagnostic trouble codes.
DIAGNOSTIC TROUBLE CODE LOCATION
SYSTEM STILL OPERATING (YES/NO)
Failed ABS Front ABS Rear Traction Std.
Device Left Right Left Right Braking
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 NO1NO YES
LR Sensor YES 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. SolenoidYES YES YES YES N0 YES
Engine Control
Module2YES YES YES YES NO YES
Voltage2NO NO NO NO NO YES
1ABS is still available in 6 sensors system if mid sensor is functional
2When ECM wiring or voltage "corrects" itself, system is restored.
FRONTOFVEHICLE
REAROFVEHICLE
DRIVER
RIGHTFRONT
LEFT FRONT
RIGHT REAR
LEFT REAR
RIGHTMID
LEFTMID
RESET
SWITCH
FIGURE 7 - EC-17™CONTROLLER LED DIAGNOSTIC
DISPLAY
FRT MID RER RHT LFT TRC MOD SEN ECU VLT
FRONT MIDDLE REAR RIGHT LEFT TRACTION MODULATOR SENSOR ECU VOLTAGE

9
ANTILOCK AND TRACTION WIRING
GENERAL NOTES
The wires that carry information and power into and out of
theEC-17™controller are generallygrouped and terminate
at a connector. The wire groups or wire harnesses along
withtheconnectorsare most oftenspecifiedand/orsupplied
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
wiresthat enter the connector are sealed to the connector.
Thewiregaugeusedin the wire harnessesisspecificto the
taskperformed.
Whendiagnosingwiringintheantilock system the following
generalrulesapplyandshouldbefollowedwhereapplicable:
1. Itisgenerallyadvisableto replace a wireharnessrather
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
cleanedrosinflux(notacidbased)andmadewaterproof.
2. Donotpiercewireinsulationwhencheckingforcontinuity.
Checkfor power,ground or continuityby disconnecting
theconnector and testingthe individual pins or sockets
inthe connector.
3. Donotspreadorenlargeindividualpinsorsocketsduring
probing.
4. Always check the vehicle handbook for wire and
connectoridentification.Individualwireidentificationwill
differ depending upon the type of connectors in use,
the vehicle manufacturer, and the system features in
use.
5. While the retarder disable, serial link, and traction on/off
connectionsarepresent on allEC-17™controllers, they
are not always used.
PREVENTIVE MAINTENANCE
Every3 months; 25,000 miles; or 900 operatinghours;
1. Check all wiring and connectors to ensure they are
secure and free from visible damage.
2. Althoughthe EC-17™controller incorporates self check
diagnostics, the optional LED display should be
inspectedtoensure that it isfunctional.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. Roadtest the vehicleby making anantilock stop froma
vehicle speed of 20 miles per hour. When an antilock
stop is made, the modulator solenoids pulsate and an
audibleburstofaircanbeheardfromoutsideofthecab.
Thewheelsshouldnotenteraprolonged"lock"condition.
Also,make a traction acceleration by accelerating ona
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 INJURYOR 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
enginebeinoperation,EXTREMECAUTION 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. Useonlytheproper 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 draintheair 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
recommendedprocedures,deactivatethe 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.

10
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 indicator
lampshould 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 RELAY VALVE
1. Remove as much contamination as possible from the
assembly'sexterior.Keep the contaminationaway from
the open ports and electrical connections.
2. Identifyand remove all air lines connected to the unit.
3. Disconnecttheelectrical connector(s) fromthe EC-17™
controller.
4. Note and mark the mounting position of the assembly
onthevehicle. Loosen, remove andsavethenutsonthe
mounting hardware that attaches the controller relay
assemblybrackettothe vehicle. Remove therelayvalve
andEC-17™controller from thevehicle.
5. Note and mark the position of the EC-17™controller
relativetothevalveitismountedon.Removeandretain
thefourhex headboltsthatsecuretheEC-17™controller
tothe valve. Then separate the EC-17™controller from
thevalve.
BRACKET MOUNTED EC-17™CONTROLLER
1. Remove as much contamination as possible from the
assembly'sexterior.Keep the contaminationaway from
openair connections and electrical connections.
2. Disconnecttheelectrical connector(s) fromthe EC-17™
controller.
3. Note and mark the mounting position of the EC-17™
controlleron 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™controllerand bracket fromthe vehicle.
4. Remove and retain the four hex head bolts that secure
the EC-17™controller to the bracket. Separate the
EC-17™controllerfrom the bracket.
INSTALLING THE EC-17™CONTROLLER
EC-17™CONTROLLER MOUNTED ON
ANTILOCK RELAY VALVE OR ANTILOCK
TRACTION RELAY 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).
2. Mount the assembled EC-17™controller and antilock
relay valve on the vehicle and orient it in the position
markedbefore removal.
3. Reconnect all air lines to the assembly.
4. Reconnect the electrical connector(s) to the EC-17™
controllerandtorquetheconnectorretainingscrew(“jack
screw”)to 15-20 inchpounds.
5. Testthevalvefor operation andleakageprior to placing
the vehicle in service.
6. Perform the "Initial Start up Procedure" in the
TROUBLESHOOTINGsectiontoassurepropersystem
operation. (Appropriate for both EC-17™& EC-17N™
controllers).
BRACKET MOUNTED EC-17™CONTROLLERS
1. Secure the EC-17™controller to its bracket using the
fourhexhead 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
retainedduringremoval.
3. Reconnect the electrical connector(s) to the EC-17™
controller and torque the connector retaining bolts to
15-20inchpounds.
4. Perform the "Initial Start up Procedure" in the
TROUBLESHOOTINGsectiontoassurepropersystem
operation.
DIAGNOSINGAND LOCATING ASYSTEM
DIAGNOSTIC TROUBLE CODE
GENERAL
The EC-17™controller contains self test and diagnostic
circuitry that continuously checks for proper operation of
theentireantilock/tractionsystem,includingwiringcontinuity.
TheEC-17™& EC-17N™controllers are programmed atthe
factory to accommodate the needs of the vehicle and the
customer'sdesires.Both the EC-17™&EC-17N™controller
canbereconfiguredbytheendusertoincludetractioncontrol
(SeetheImportantnoticeconcerningtheEC-17N™controller).
A vehicle equipped with traction control can generally be
identifiedbynotingthepresenceofadashmountedcondition
lamp,a disable switch (for the traction control system) and
atractionsolenoid located above therelay valve.

11
Separate dash lamps, controlled by the EC-17™/EC-17N™
controller, advise the driver of the condition of the entire
antilock/traction system.
Whenthecontrollersenses an erroneouscondition,itstores
the condition in memory, illuminates the dash mounted
condition lamp and after certain criteria are met it disables
the antilock or traction control function. If so equipped, the
EC-17™controller illuminates the appropriate diagnostic
LEDs.
The diagnostic trouble code condition is truly stored and is
not cleared by loss of power to the antilock system. The
optional LEDs will illuminate when power is restored and
remain illuminated until the failure is corrected. After the
actualissueis corrected, maintenancepersonnelcan clear
orreset theEC-17™controllerdiagnosticsthroughtheS.A.E.
J1587diagnosticlinkortheoptional magnetic RESET point
in the diagnostics display. To clear or reset an EC-17N™
controller (not equipped with LEDs) the S.A.E. J1587
diagnostic link must be utilized.
IMPORTANT:
The balance of this manual deals with diagnostics and
controller self-configuration using the optional LED
displayon the EC-17™controller (see Figure1). Antilock
systems using the EC-17N™controller (see Figure 1)
must use the Bendix, Diagnostic Communication
Interface or DCI for diagnostics or reconfiguration.
Used with its Microsoft Windows* based software and a
personalcomputer,theDCIisabletoprovidethetechnician
with a high level of diagnostic information and antilock
diagnostic trouble code history. This is particularly useful
when attempting to determine the source of intermittent
diagnostic trouble code indication from the antilock dash
conditionlamp.
Forfielduseor when aPCisnotavailable,theDCI’sintegral
LED display and switch provides the EC-17N™controller
userwithexactlythesameinformationthatisavailablefrom
the optional LED display on the EC-17™controller. When
usingtheDCI’sLEDdisplayforsystemdiagnosisorcontroller
self-configurationthedescriptionsandprocedurespresented
* Windows is a registered trademark of Microsoft Corporation.
VEHICLE DIAGNOSTIC
CONNECTOR (J1587)
FIGURE 9 VEHICLE DIAGNOSTIC CONNECTOR
LOCATION
DIAGNOSTIC COMMUNICATION INTERFACE
TheDCI (part#5004893)isaduallevelelectronicdiagnostic
toolfor either the EC-17™or EC-17N™antilock controller. It
caneitherbeused as a “standalone”diagnostic tool or with
Bendix’s AComFor Windows software (part # 5004892).
InordertousetheDCI, the vehicle must beequippedwitha
J1587 diagnostic link connector as illustrated in Figure 9.
This connector is generally located on the driver’s side, in
lowerportion of the dash orunder thedash panel.
MPSITool:MultiProtocolCartridge(J38500-1500),PCMCIA
CardForBendix(J38500-2400). FIGURE 10 DCI CONNECTED TO LAP TOP COMPUTER
DCI
SERIAL
CABLE
LAP TOP
COMPUTER
TO VEHICLE
J1587
CONNECTOR
DIAGNOSTIC
LAMPS RESET
SWITCH
COMPUTER
SERIAL PORT
CONNECTOR
J1587
DIAGNOSTIC
CONNECTOR
(CONNECTED
TO VEHICLE)
POWER AND
COMMUNICATION
INDICATION LAMPS
FIGURE 8 DIAGNOSTIC COMMUNICATIONS INTERFACE

12
inthis manual can be used. When connected to a PC,use
theinstructions and documentationpackaged with theDCI
to troubleshoot or reconfigure the EC-17™/EC-17N™
controller.
For more information on the Bendix Diagnostic
CommunicationInterface,seeyourlocalauthorized Bendix
partsoutletorcall1-800-AIR-BRAKE(1-800-247-2725).
OPTIONAL DIAGNOSTIC LEDS & RESET
Theconditionofspecific components is providedbyaseries
of labeled, light emitting diodes (LEDs) in the EC-17™
controllerhousing.Nospecialtoolsorequipmentareneeded
toreadorinterprettheEC-17™controllerdiagnosticdisplay.
It should be noted that the EC-17™controller diagnostics
display is separate from the antilock and traction condition
lampsonthe dash. Withthisseparation, the driverisaware
of any issues that occur but is not confused by diagnostic
information.TherearetenLEDsplusamagneticallyactuated
resetswitch. The firstsix LEDs locatean issue toa specific
areaofthevehicle,andthenextthreeindicatethecomponent
or its wiring. The LEDs are software driven and are either
ON or OFF depending upon their monitor function. (Note:
rightandleft,frontandreararedetermined from the driver’s
seat.) Note: The non LED EC-17N™controller is also not
equippedwith a magneticreset.
FRT Red LED
MID RedLED(SeeNote)
RER RedLED
RHT RedLED
LFT RedLED
TRC Red LED
MOD RedLED
SEN RedLED
ECU Red LED
VLT Green LED
RESET + No LED
Note: TheMIDLED is usedwithsomebutnotallvehicles.
Whensix speed sensorsare not installed this LED
is not used in the diagnostic process. However, it
will light when a magnet is placed on the RESET
switch in the diagnostic display.
"FRT"(Front)LED
ThisRedLED illuminates inorderto indicate thelocationof
a component or its wiring. It will light in conjunction with
eithertheRIGHTorLEFTLEDandtheMODorSENSLED.
"MID" (MiddleAxle)LED
This Red LED is not used in all installations. On those
vehicles that have six speed sensors installed, this Red
LED illuminates to indicate the location of a speed sensor
or its wiring. The "MID" LED should not illuminate with the
"MOD"LED.
Both the Antilock & Traction dash lamps are
ON during the system self test.
This is the first blink occurrence of the
Antilock dash lamp. Compare and note the
traction lamp’s reaction to the Antilock lamp.
Both dashlamps are OFF and remain OFF at
theendof the powerupsequence.
This is the second blink occurrence of the
Antilock dash lamp. Compare and note the
traction lamp’s reaction to the Antilock lamp.
Torque Limiting & Torque Limiting Differential
Differential Only Braking
Braking Only
ON ON ON ON ON ON
OFF OFF OFF ON OFF OFF
ON ON ON ON ON ON
OFF OFF OFF OFF OFF ON
ON ON ON ON ON ON
OFF OFF OFF OFF OFF OFF
ANTILOCK TRACTION
DASH DASH
LAMP LAMP
ANTILOCK TRACTION
DASH DASH
LAMP LAMP
ANTILOCK TRACTION
DASH DASH
LAMP LAMP
LAMP CONFIGURATION TABLE

13
"RER"(Rear)LED
ThisRedLEDilluminatesinordertoindicate thelocationofa
component or its wiring. It will light in conjunction with either
theRIGHTorLEFTLED and the MODorSENSLED.
"RHT"(Right)LED
ThisRedLED illuminates inorderto indicate thelocationof
a component or its wiring. It will light in conjunction with
either the FRONT or REAR LED and the MOD or SENS
LED.
"LFT"(Left)LED
ThisRedLEDilluminatesinordertoindicate thelocationofa
component or its wiring. It will light in conjunction with either
theFRONT or REAR LED and the MOD or SENS LED.
"TRC"(Traction)LED
ThisRedLED illuminatestoindicateapermanentdiagnostic
trouble code in the traction control system. It may be
illuminated with the MOD LED or may illuminate by itself.
NOTE: If a problem may exist with the wiring to the engine
controlmodule (ECM), this LED will go on.
"MOD"(Modulator) LED
ThisRedLEDilluminatestoindicateanopenor short circuit
in the solenoids of one of the four modulators or the wiring
connectingthem tothesystem.Whenindicatingadiagnostic
trouble code with a modulator this LED will be illuminated
with two positioning LEDs (RHT/LFT + FRT/RER). NOTE:
TheMIDpositioningLEDshouldnot be illuminated withthis
LED. This LED is also used to indicate a possible problem
with an ATR-1™or ATR-2™valve, antilock traction relay,
solenoid.Whenilluminated for atractionsystem diagnostic
trouble code the TRC LED will also be on.
"SEN"(SpeedSensor)LED
ThisRedLEDilluminatestoindicateanopenor short circuit
in one of the speed sensors or the wiring connecting them
to the system. The "SEN" LED will be illuminated with two
positioningLEDs(RHT/LFT+FRT/MID/RER).
"ECU" (ElectronicControlUnit) LED
ThisRedLED, whenilluminated,indicatesthatthecontroller
itselfhasfailed. Beforecontrollerreplacementisconsidered,
alwayscheck vehicle voltagetothe controller.
"VLT"LED
ThisGreenLEDilluminates and remains ONduringvehicle
operation to indicate that vehicle power is reaching the
controller.If vehicle powerisout of range(below10 VDC or
above 18.0 VDC) this LED will flash until power is brought
intorange.
"RESET"
Beneath the RESET area of the display is a magnetically
sensitiveswitchthat is usedto reset thediagnosticsystem.
The device will respond to a magnet which has strength
sufficienttolift athree(3)ounceweight.Momentarily holding
a magnet against the RESET will causeALL LEDs to light
during the time the magnet is against it. Holding a magnet
against the RESET longer than 20 seconds will cause the
EC-17™controllerto initiate theself configuration feature.
EC-17™CONTROLLER CONFIGURATION
IMPORTANT GENERAL NOTE:
The following information and procedure applies to the
EC-17™controllerequippedwiththeoptionalLEDdiagnostic
display and magnetic RESET switch. Controllers without
this option (EC-17N™) must use the J1587 diagnostic link
andtheDCIwithitsrelatedcomputerprogramstoreconfigure
the controller. See the documentation and instructions
packagedwith the equipment for specifics.
EC-17™CONTROLLER CONFIGURATION DISPLAY
1. Turntheignition ON.
2. All LEDs will illuminate then go out.
3. The number of active sensors will be displayed by the
momentary illumination of the red SEN (sensor) LED
and two or more of the red locating LEDs. No other
LEDs will be on.
A. SEN + FRT (front) + RER (rear) = A four sensor
configuration (all systems must have at least a 4
sensorconfiguration)
B. SEN + FRT + MID (middle) + RER = A six sensor
configuration
4. Thered TRC LED will momentarilyilluminate by itself if
traction control torque limiting is active, if not, then the
display will go to the condition described in #5.
5. TheredTRCandMODLEDswill momentarily illuminate
iftractioncontroldifferentialbrakingisactive,ifnot,then
the display will go to the condition described in #6. No
other LEDs will be on.
6. Thediagnosticdisplaywillreturntoitsnormaloperational
status. Assuming no diagnostic trouble codes exist in
the antilock or traction system, all red LEDs will be off
and the single, green, VLT LED is illuminated.
EC-17™CONTROLLER SELF CONFIGURING
PROCESS
Important General Information:
1. Three aspects of the antilock and traction system are
influencedbythe self configuringfeature of theEC-17™
controller.
A. Speed Sensors: The number of speed sensors
connectedto the EC-17™controller will bedetected
during the self configuration process. The EC-17™
controller will check the MID SEN (mid axle speed
sensor) locations on its connector to determine if a
sensor is connected to it and will default to a six
sensor configuration if it detects even one sensor

14
connected. If mid axle speed sensors are not
detected,the EC-17™controller willdefault to afour
sensorconfiguration.(Twofrontandtworear)
B. ElectronicEngine Control: Onunitsmanufactured
prior to mid-year 2000, if the EC-17™controller is
connected to the control module of an electronic
engine, the torque limiting and differential braking
feature of ATC will be activated when the traction
enable/disable switch is toggled prior to self
configuration. After mid-year 2000, the electronic
engine must transmit the throttle position via the
J1922 or J1939 serial link for ATC to be activated
duringwheelspin.
C. Antilock Traction Relay Valve: If the solenoid
assembly in the ATR™valve is connected to the
EC-17™controller,thedifferentialbrakingfeatureof
traction control will be activated during the self
configuringprocess.
D. Traction Disable Switch: The traction disable
switch must be toggled prior the self configuration
process.
2. Nomethod is available todisable the self configuration
feature.
3. Dueto the extendedperiod of time the magnetmust be
held on the RESET to initiate the self configuration
process (20 seconds), it is unlikely that a self
configurationwouldoccur accidentally.
4. Basic,four speed sensor,antilock operation can not be
removedduringthe self configuration process.This is a
minimumconfigurationfor all EC-17™controllers.
5. If a speed sensor is connected to either wheel on the
mid axle, the EC-17™controllers will configure for six
sensors. If no mid axle speed sensor is detected, the
EC-17™controller will configure for four sensors. Any
disconnected speed sensor(s) will register as a failure
on the diagnostic display at the end of the EC-17™
controller self test.
6. All or part of traction control can be lost during self
configuration by;
A. Not connecting one of the wire harnesses (engine
control module for torque limiting and ATR™valve
solenoidfordifferentialbraking).
B. A missing or inoperative traction control enable
disable switch.
C. Nottogglingthetractioncontrolenable/disableswitch
in the “traction enabled” after power up, but prior to
theself configuration. The operator can tell that the
traction features are lost by noting the absence of
thetractionlampflash upon power up.Theoperator
should note the flashing of the antilock condition
lamp,and thetractionlampiftraction equipped,upon
every power up. Observing the dash lamps is one
method the operator has to verify the system
operation.
7. TheEC-17™controllercanbereprogrammedupto10,000
times.
8. Whenareplacement EC-17™controllerisinstalled on a
vehicle that does not have one or more of the
preprogrammedfeatures, a failurewill be registeredon
thedashlamp(s)andontheEC-17™controllerdiagnostic
display. For this reason it is necessary to perform the
selfconfiguringprocedure.
9. Someconfigurationinformationisavailablebyobserving
the reaction of the dash condition lamps on vehicles
configured with traction control and equipped with the
self configuring EC-17™controller. When the ignition is
switched ON, the EC-17™controller self test is begun.
During the self test the dash lamps will flash on and off
together as indicated in the chart, depending upon the
type and amount of traction control configured into the
EC-17™controller. Note: For more information on this
subject see the TROUBLESHOOTING section of this
document.
Self Configuration Process
Inordertosuccessfullycompletetheselfconfiguringprocess
followthe steps presented.
1. Connectallantilockandtractioncontrolwireharnesses.
Referto the schematicin Figure 5.Make certain thatall
thespeedsensorspresentonthevehicleareconnected
(H2,H3, J1, J2on the 30pin connector andE2, E3, F2,
F3,B2,B3,C2,C3onthe18pinconnector).Ifthevehicle
has an electronic engine and traction control torque
limiting is desired the engine control module must be
connected(B2andB3 on the 30 pinconnectorforJ1922
orC3,D2, and D3on the 30pin connector forJ1939). If
thevehicleisequippedwitheitheranATR-1™orATR-2™
valve, the solenoid connection must be made to the
EC-17™controller(D2 and D3 on the 18 pin connector)
inorder to obtaintraction control differential braking.
2. If the vehicle is to be configured with traction control, it
must have a traction control dash lamp and a traction
controlenable/disableswitch.Both the lamp andswitch
mustbe functional.
3. Turnthe ignition ON,toggle thetraction control enable/
disable switch back and forth then hold a magnet on
theRESETposition of theEC-17™controllerdiagnostic
display until the LEDs begin to flash then remove the
magnet. If the magnet is not removed during the LED
flashing a second self configuration may be initiated.
The magnet may have to be held on the RESET for as
longas20 seconds.Whentheselfconfigurationprocess
is complete the EC-17™controller will automatically go
through a self test. During the self test the diagnostic
displaywill indicate thenew configuration as described
under the section entitled EC-17™Controller
Configuration Display. Note: If the EC-17™controller is

15
being configured with traction control (either torque
limiting,differential braking or both),the traction control
condition dash lamp, will be illuminated as well as the
appropriate LEDs on the EC-17™controller diagnostic
display.Thetractioncontroldashlampwillbeilluminated
until the traction control enable/disable switch is placed
in the traction control enabled position (traction control
operative).
4. Place the traction control enable/disable switch in the
traction control enabled position (traction control
operative),the traction control dashlamp should beoff.
5. Before placing the vehicle in service, verify the
configuration and the system condition by turning the
ignition OFF then ON while observing the EC-17™
controller diagnostic display. The diagnostic display
should indicate the desired configuration as described
under the section entitled EC-17™Controller
Configuration Display and no red LEDs should be
illuminated at the end of the self test.
6. If the configuration appears correct but the diagnostic
LEDsindicate a failure somewhere in the system,refer
to the General Configuration Information section and
usetheTroubleshootingsectionofthismanualtolocate
andrepair the diagnostictrouble code.
7. If the configuration is incorrect, the process can be
repeatedas required. Onecommon error is performing
theselfconfigurationwithout toggling the tractioncontrol
enable/disable switch. This will prevent any traction
featuresfrombeing activated. Note:Thetraction switch
mustbetoggled toconfiguretraction,butmustbe placed
intheenable position toallow the tractionlamp to flash.
TROUBLESHOOTING
IMPORTANT BEFORE TROUBLESHOOTING:
1. Determineifthevehicleisequippedwithtraction control.
The presence of a traction condition lamp on the dash
can be used.
2. Some vehicles are equipped with a traction control
"disabling switch." If so equipped, ENABLE THE
TRACTION SYSTEM BEFORE BEGINNING THE
TROUBLESHOOTING. THE TRACTION CONTROL
MUST BE DISABLED FOR DYNAMIC TESTING.
3. If the vehicle is equipped with traction control and is a
tandem axle unit, note the number of drive axles. The
"MID" diagnostic LED is used only on 6x4 vehicles.
GENERAL
While the EC-17™controller diagnostic display locates a
specificdiagnostic trouble code area, itis stillnecessary to
confirmwhether the problem may reside in the component
itselforthewiring. The following troubleshootingprocedure
isdevotedtonarrowingthediagnostictroublecodetoeither
the wiring or a specific antilock or traction component. It
should be noted thatALL TROUBLESHOOTING BEGINS
BY OBSERVING THE ANTILOCK AND TRACTION
CONDITION LAMPS ON THE DASH. All troubleshooting
should begin by first performing the "Initial Start up
Procedure"and following the directions containedin it.
TROUBLESHOOTING TIPS
1. Begin by observing the dash condition lamp(s) and
performingthe"Initial Start Up Procedure."
2. Thetroubleshootingtechnicianshouldrecord all findings
andtheactiontaken during the troubleshootingprocess.
3. No voltage or resistance tests are performed into the
EC-17™controller.All voltage and resistance tests are
performed by beginning at the wire harness half of the
connectorandmovingAWAYfromtheEC-17™controller
toward an antilock traction system component
(modulator,wheelspeedsensor, etc.)

16
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
GOTO
SECTIONIV ON
(NOTFLASHING)
ONEOR
MOREON
ONEFROMTHIS
GROUPON
ONEFROMTHIS
GROUPON
ON- GO TOSECTIONVI A ON-GOTOSECTIONVIIA
ONEFROMTHIS
GROUPON
ONEFROMTHIS
GROUPON
NOTHINGON-GO
TOSECTIONV
FLASHING-GOTO
SECTIONV ON(NOTFLASHING)-GO
TOSECTIONII
DIAGNOSTIC DISPLAY
QUICK REFERENCE
Thisindexispresentedforthebenefitofpersonnelexperiencedin
troubleshooting Bendix full-vehicle wheel control antilock with
tractioncontrol. Itprovidesaquickreferencetospecificsections
thatprovidetestingproceduresandvalues.
ON - GO TO
SECTIONXII
ON - GO TO
SECTIONXI

17
TURN IGNITIONONAND
OBSERVEDASHANTILOCK
LAMP.
DIDANTILOCKDASHLAMPBLINK?
ISANTILOCKDASHLAMP
STILLILLUMINATED?
YES
YES
GOTOSECTIONIII
“INSPECTIONFOR
ILLUMINATED
LEDs”
INCREASE VEHICLE SPEED TO ABOVE 7
MPH FOR AT LEAST 10 SECONDS AND
OBSERVE THE DASH LAMP.
DASH LAMP ILLUMINATES
NO
ANTILOCK DASH LAMP DOES
NOT BLINK, COMES ON AND
REMAINS ILLUMINATED
START HERE
NO
ISVEHICLEEQUIPPEDWITH
TRACTIONCONTROL?
YES
THEANTILOCKSYSTEM IS
FUNCTIONINGNORMALLY. MAKE
NOTEOFANYPARTSREPLACEDOR
REPAIRED.
NO
TURN IGNITIONOFFTHEN
ONANDOBSERVEONLY
THETRACTIONCONTROL
DASHLAMP. DIDTRACTION
CONTROLLAMPBLINKTHEN
GOOUT?
THE TRACTION SYSTEM IS
FUNCTIONING NORMALLY.
YES
NO
MAKECERTAINTRACTION
ISENABLED(WITHVEHICLE
STATIONARY,LOCATE&ACTI-
VATETHEREMOTETRACTION
ENABLESWITCH).RETEST
DIDTRACTIONCONTROL
LAMPGOOUT? YES
ISTRACTIONDASH
LAMPILLUMINATED?
GOTOSECTIONXI
"TESTINGTRACTION
CONTROLMODULATOR"
YES
NO
GOTOSECTIONX
"TESTINGTHETRACTION
DASHLAMP"
NO
YES
NO
IftheEC-17™controllerhasbeenrecentlyreplaced,make
certain it is configured properly for the vehicle. If traction
control is part of the configuration, the "enable - disable"
switch must be toggled after power has been applied to
the EC-17™controller and before self configuring process
(traction control operable).
GO TO SECTION II “INSPECTION
FOR ILLUMINATED LEDS”
YES
ANTILOCK DASH LAMP DOES
NOT BLINK, DOES NOT COME
ON. GO TO SECTION I.
NO
INITIAL START-UP PROCEDURE
AFTER mid-year 2000 A
SERIAL COMMAND NEEDS
TO BE SEEN ON THE J1922
OR J1939 LINK FOR TRAC-
TION TO FUNCTION

18
SECTION I - ANTILOCK DASH LAMP TESTING
YES
NO
CHECKWIRINGHARNESSANDRELAYFOR
SHORTSTOGROUND. RECONNECTAND
CHECK/REPLACETHEFOLLOWING:
1.DASHLIGHTBULB
2.FUSE
3.RELAYPOWERWIRE
4. RELAY
AFTERREPLACINGEACHCOMPONENTTEST
THEDASHLAMP.
REPLACETHEEC-17™
CONTROLLER
NO NO
STARTHERE
E3
TODASHLAMP
RELAY
A3
GROUND
A1
GROUND
A2
GROUND
REPAIRORREPLACE
WIREHARNESS
REPLACERELAY&
RETESTFORBATTERY
VOLTAGE
SECONDTIMETO
THISPOINT?
ISVOLTAGECORRECT?
REPEATTHE“INITIAL
START-UPPROCEDURE”
WITHIGNITION ON,MEASURE VOLTAGEBETWEEN
PINS E3 & A1, A2, A3. VOLTAGE SHOULD BE SAME
AS BATTERY VOLTAGE
YES
YES
DISCONNECT30PINCONNECTORFROM
EC-17™CONTROLLERANDOBSERVETHE
ANTILOCKDASHLAMP.
ANTILOCKDASH LAMP
ILLUMINATED?
A1,A2, A3
GROUND
DASHLAMP
RELAY
VEHICLEPOWER
(IGNITION)
E3
TODASHLAMP
RELAY
DASHLAMP

19
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT
SECTION II - INSPECTION FOR ILLUMINATED LEDs
CHECKCLOSELYAND
NOTEIFGREEN,VLT
LEDISILLUMINATED
NO(OFF)
YES
NO
YES (ON)
GOTO SECTIONV
“TESTINGFORPOWER
TOTHEEC-17™
CONTROLLER”
YES
AREANYREDLEDs
ILLUMINATED?
NO
YES
NO
INSPECTEC-17™
CONTROLLERFORPRESENCE
OFILLUMINATEDLEDSAND
RECORD
STARTHERE
AREANYREDLEDs
ILLUMINATED?
ISGREENLEDFLASHING?
EC-17™CONTROLLER
DIAGNOSTICDISPLAY
GREENVLT LED
REDLEDs
REPLACETHEEC-17™
CONTROLLER
GOTO SECTIONV “TESTING
FORPOWERTOTHEEC-17™
CONTROLLER”.
NOTEANDRECORDTHE
CONDITIONOFALLRED
LEDs
GOTOSECTIONIV
“INSPECTIONFOR
ILLUMINATEDLEDs”
GOTOSECTIONVIII“TESTINGFOR
FALSEFAILUREINDICATION-
CAUSED BY DASH LAMP RELAY”

20
SECTION III - INSPECTION FOR ILLUMINATED LEDs
ISGREENLEDFLASHING?
YES
NO
YES
GOTO SECTIONIX “TESTINGFOR
FALSEFAILUREINDICATION-CAUSED
BY WHEELSPEEDCOMPONENTS”
NO
YES
YES
NO
NO
INSPECTTHEEC-17™CONTROLLER
FORPRESENCEOFILLUMINATEDLEDS
ANDRECORD
STARTHERE
GOTOSECTIONIV“INSPECTION
FORILLUMINATEDLEDs”
EC-17™CONTROLLER
DIAGNOSTICDISPLAY
GOTOSECTIONV
“TESTINGFOR
POWERTOTHE
EC-17™CONTROLLER”
ISGREENVOLTLED ILLUMINATED? AREANYRED
LEDs
ILLUMINATED?
GOTO SECTIONV
“TESTINGFORPOWER
TOTHEEC-17™
CONTROLLER”
REPLACETHEEC-17™
CONTROLLER
AREANYREDLEDsILLUMINATED?
NOTEANDRECORD
THECONDITIONOF
ALLREDLEDs
MOD
RESET
FRT
RER
MID
RHT
LFT
TRC
SEN
ECU
VLT