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ABS/ASR „D“- „Cab“ - VersionAnti-Lock Braking System for Commercial Vehicles
1st Edition
Copyright WABCO 2006
Vehicle Control SystemsAn American Standard Company
The right of amendment is reservedVersion 001/12.99(en)
8150100013 815 010 001 3
31
Page
1. INTRODUCTION 4
2. SYSTEM FUNCTIONS 5
3. SYSTEM DESIGN ANDCOMPONENTS 8
4. ABS / ASR SYSTEM DESCRIPTION 10
5. OTHER COMPONENTS 17
6. INSTALLATION 26
7. ANNEX 31
Contents ABS-D
4
1. Introduction
IntroductionABS-D1.Anti-lock Braking Systems (ABS) or- to use another common term - au-tomatic anti-lock systems - are usedto prevent a vehicle’s wheel fromlocking as a result of excessive op-eration of the service brake, espe-cially on a slippery road surface.Thus lateral control on the wheelsbeing braked is maintained even atfull brake application or in panicbraking situations to ensure the cor-nering stability and steerability of avehicle or a tractor-trailer combina-tion to the greatest possible physicalextent.
At the same time, the objective is tooptimize the utilization of the availa-ble adhesion coefficient betweentyres and the road surface and thusvehicle retardation and stopping dis-tance.
High-performance ABS for commer-cial vehicles was first introduced atthe end of 1981 by Mercedes-Benzand WABCO after elementary sys-tems had been used in the USAfrom the mid 70s.
System design and control princi-ples of this 4-channel system withindividual wheel control (4 sensors -4 modulators, called 4S/4M below)were subsequently highly success-ful in the European market for com-mercial vehicles and became thebasis for a world-wide standard forall commercial vehicles with powerbrakes.
ABS and ASR have proved their val-ue as 4- and 6-channel systems incommercial vehicles. The reliabilityof systems and components fromseries production is excellent, inspite of their complexity. The de-
mand is rising not only in Germanyand Europe or Israel and Australia,but also in the USA and in Japan.
As is generally known, the EEC andother legal requirements demandautomatic anti-lock braking systemsfor certain types of commercial vehi-cles.
It is these provisions and measureswhich have resulted in the evenmore widespread use of ABS and ingreater numbers being produced;this in turn has allowed cost reduc-tions to be implemented, in spite ofkeen competition. WABCO has nowdeveloped the 4th generation of ABSand ABS/ASR. The D-generation of-fers different variants in the form ofmodular system designs.
These are based on state-of-the-artelectronics technology with high-performance micro computers, in-cluding data storage, and take intoaccount recent diagnostic princi-ples. The 4- and 6-channel ABS/ASR systems for commercial vehi-cles offer various interfaces forworking together with electronic en-gine control systems and the opti-mal use of an integrated speedlimiting facility. Special functions forboth ABS and ASR operation areavailable for selection in off-road op-erations.
This document describes the basicelements and the operation, the de-sign and the system configurationsof these anti-lock systems for com-mercial vehicles. The subject ofdrive-slip control (ASR) is men-tioned only briefly in the section onsystem functions.
5
In case of impending wheel lock, thebrake pressure of the correspond-ing wheel will be decreased, heldduring expected or measured wheelre-acceleration and subsequentlyincreased in steps after re-accelera-tion. The cycle is started again if thebrake force is still too high for theactual friction level (adhesion).
Rear axle wheels are subject to indi-vidual control (IR), front axle wheelsare subject to Modified IndividualRegulation (MIR).
Fig. 1 shows an exam-ple of a control cyclewith the most importantcontrol variables, wheeldeceleration threshold-b, wheel accelerationthreshold +b and slipthresholds λ1 and λ2.
As the brake pressureincreases, the wheel isprogressively deceler-ated. At point 1 wheeldeceleration exceeds avalue that can not phys-ically be exceeded byvehicle deceleration.The reference speed,which up to this pointhad been the same asthe wheel speed, nowdiverges and is reducedaccording to a fictitiousvehicle retardation frompoint 2 (exceeding the-b threshold) with a
slower deceleration.
The deceleration threshold -b is ex-ceeded at point 2. The wheel nowmoves into the unstable region ofthe µ-λ slip curve at which point thewheel has reached its maximumbraking force and any further in-crease in braking torque does notachieve any further deceleration ofthe vehicle but merely deceleration
of the wheel. For this reason thebrake pressure is quickly reducedand so wheel deceleration decreas-es. The time taken for wheel decel-eration is determined by thehysteresis of the wheel brake andby the characteristic of the µ-λ slipcurve in the unstable region.
Only after the wheel brake hystere-sis has been overcome a continuedreduction in pressure leads to a de-crease in wheel deceleration.
At point 3 the wheel decelerationsignal -b drops below the thresholdand the brake pressure is held at aconstant level for a set time T1.
Normally, wheel acceleration willexceed the acceleration threshold+b within this set time (point 4). Aslong as this threshold is exceeded,the brake pressure is kept constant.If (for example on a low-friction sur-face) the +b signal is not generatedwithin time T1, the brake pressure isfurther decreased by slip signal λ 1.During this control phase the higherslip threshold λ 2 is not reached.
At point 5, the curve falls below thethreshold +b. The wheel is now inthe stable region of the µ-λ slipcurve.
Brake pressure is now rapidly ap-plied for time T2 to overcome thebrake hysteresis. The time T2 isfixed for the first control cycle andthen recalculated for each subse-quent control cycle. After the initialrapid phase, brake pressure is thenincreased more gradually by ”puls-es”, by alternating pressure holdand pressure increase.
The basic logic demonstrated in thisexample is not fixed at all; it adaptsto the corresponding dynamic re-sponse of the wheel to varying coef-ficients of friction, i.e. it implementsan adaptive type of system control.
2.1 Description of an ABS control cycle
System Functions ABS-D 2.
T2
T1
1 2 3 4 5 6 7 89pres
sure
in
whe
el b
rake
cyl
inde
rty
re c
ircum
fere
nce
acce
lera
tion
inlet valve
outlet valve
spee
ds
+ b
- b
λ1
λ2
wheel speed reference speed
vehicle speed
t
t
t
t
t
Fig. 1
2. System functions
6
2.1.1 Off-road ABS The off-road mode can be used toallow more brake slip (temporarywheel lock) for braking on specialsurfaces. ECE R13 SupplementNo. 7 requires the off-road ABSfunction to be reset as soon as theignition is switched on again.
The vehicle manufacturer decides,according to vehicle type and appli-cation, whether this switch is fitted ornot. Off-Road ABS disables ABScontrol at vehicle speeds of lessthan 15 km/h and allows greaterbrake slip up to 40 km/h At speedsabove 40 km/h there is no modifica-tion to ABS control.
The mode selected is indicated tothe driver by the warning lamp (WL)which will flash slowly unless otherevents result in a permanently litwarning lamp. The speed rangesand the warning light function can bealtered via parameter settings. Thevehicle manufacturer has to recordin the driver’s handbook that the off-road mode may not be used in ordi-nary road traffic because the vehiclemight not meet the requirements ofECE 13 Cat.1 in these circumstanc-es.
System FunctionsABS-D2.All threshold values depend on sev-eral different parameters, such asdriving speed, vehicle deceleration,etc.
The number of control cycles resultsfrom the dynamic response of theoverall control system composed ofthe ABS-control - the wheel brake -the wheel - the road. Here, the fric-tional connection is of vital impor-tance. In general, 3 to 5 cycles persecond are performed, but signifi-cantly fewer on wet ice.
If an engine brake / retarder is usedduring an ABS control cycle, it isswitched on or off by the ECU. Forthe purpose of front axle ModifiedIndividual Control (MIR), the systemcompares the front wheel signalsand modulates the pressure for bothfront wheel brakes. If, for example,control is activated on a front wheel
on a road surface with partially loweradhesion, the other wheel channelregulates the brake pressure so thatpressure differences are built up(slowly, in graduated steps) to a lim-ited maximum value.
In the event of a 4S/3M -or 6S/3Mconfiguration being used, there isonly one modulator on the front axle.The wheel locking first takes overABS control of this axle. This resultsin a control process similar to SelectLow which is called Modified AxleControl (MAR).
On 6x4 or 6x2 vehicles with a 6S/4Msystem, the same philosophy isused on the two rear wheels of oneside which are controlled by onemodulator. This type of system iscalled Modified Side Control (MSR).
7
In addition to ABS control, trucksand buses can be equipped with anAnti Spin Regulation ASR, alsoknown as drive-slip control. ASR re-duces the amount of wheel spin(drive slip). The philosophy of ASRis based on keeping the slip of spin-ning drive wheels compared to thenon-driven front wheels within arange providing the best possibletraction and stability.
Depending on the road conditionsASR will start engine and/or brakecontrol, if excessive wheel slip hasbeen detected. On a homogeneousroad surface, control is mainlyachieved by reducing the speed ofthe engine, and differential brakecontrol will be limited to synchroniz-ing the wheels. If µ-split conditionsapply, differential brake control willput pressure only to the brake cylin-ders of the wheel which is spinning.The engine torque is thus trans-ferred to the other wheel.
Engine control will not commenceuntil both wheels spin or the slip ofthe spinning wheel exceeds a cer-tain threshold. During differentialbrake control, the pressure is sup-plied by way of actuation of the dif-ferential brake valve. The brake
pressure of the wheel which is spin-ning is controlled by the correspond-ing ABS solenoid control valve.
To prevent pressure building up inthe brake chamber for the drivingwheel which is not spinning, theABS solenoid control valve of thiswheel will cut off brake pressure.This cut-off function is also availablefor the Z-axle modulators of a 6-channel system or optionally for aseparate solenoid valve in case of a4-channel system on a 6x2 vehicle.To prevent the foundation brakefrom overheating, the differentialbrake threshold is subject to a linearincrease at vehicle speeds over 35km/h, thus increasingly controllingslip by means of slowing the enginespeed. When the vehicle’s speedexceeds 50 km/h, differential brakecontrol will not commence althoughany brake control in process willcontinue. ASR for 6x4 vehicles with a 6S/4Mor 6S/6M system takes the speedsand accelerations of both wheels ofone side into account. In compari-son to a 4S/4M system, this systemis able to avoid spinning or locking ofthe driving wheels which have nosensors.
2.2 ASR
2.2.1 Traction mode In deep snow or comparable condi-tions the traction can be increasedby activating a special mode. Bytemporarily pushing the tractionmode button for at least 150 milli-seconds, the ECU switches to a typeof ASR control with different thresh-olds and different engine/differential
brake distribution to allow higher slipratios. Depending on the parame-ters set on the ECU, an ordinaryswitch may be used for this purpose.Activation of the ASR traction modeis confirmed by slow flashing of theASR lamp to inform the driver thatvehicle’s stability might be impaired.
2.3 Speed limiter with proportional valve
System Functions ABS-D 2.
The auxiliary output can be used forlimiting the speed using a propor-tional valve and an ASR operatingcylinder. These components actuatean injection pump and consequentlymodulate the speed of the vehicle.
An idle stop cylinder is needed forcertain single-lever injection pumps.
The speed limiter meets ECE re-quirements. The speed limiting valueis part of the parameter record and isstored in the EEPROM. The stand-ard parameter record has a defaultspeed limiting value set to 160 km/h
This value can be changed via thediagnostic interface. The minimum
8
3. System design and components
3.1 System description The Anti Lock Braking System(ABS) for commercial vehicles com-prises the following components:
q 4 or 6 wheel sensors, sensorclamping bushes and polewheels
q between 3 and 6 solenoid controlvalves
q Electronic Control Unit (ECU)
q Warning lamp, diagnostic inter-face, relay or data interface forretarder control
q switch for the ABS off-road func-tion
q harness for cab, frame, ground(3), power supply (fused)
In addition, Anti Spin Regulation(ASR), also known as drive slip con-trol, comprises:
q differential brake valve
q double check valve
q ASR Lamp
q push-button switch or normalswitch for the ASR (ATC) tractionmode function
q engine control interface (SAE J1922, SAE J 1939, PWM in/out,PRIO/PWM out) or depending onthe ECU variant used
q proportional valve
q control (operating) cylinder
q idle stop cylinder
System Design and ComponentsABS-D3.value is 20 km/h For vehicles withnon-synchronized gearboxes, theneutral position has to be allocatedto the related input or additionalequipment is necessary.
A second speed limiting value canbe defined as part of the procedurefor setting the parameters (lowestspeed setting). When the speed set-ting switch is actuated, the currentspeed is stored and compared to theparameter value for the speed set-ting. The vehicle’s speed is limitedto the higher of the two values aslong as the speed setting switch isactuated.
The signal from a tachograph whichis connected to the C3/B7 input port
is required to give off between 2,400and 24,000 pulses per kilometre.Suitable appliances are, for in-stance, the KIENZLE tachographs1314 or 1318.
The ECU checks the input signal forplausibility and signalling errors.Any error is indicated by the warninglamp or ASR lamp if the vehicle ismoving at a speed faster than 3 km/h
If no C3 signal is available, thewheel speed signals from the ABS/ASR system are used to limit thespeed (does not comply with ECregulations!).
9
The following may also be included:
q a normal switch or push-buttonfor the speed-setting function
q a switch for temporarily switch-ing of the limiting speed if the ve-hicle does not have a synchro-mesh gearbox.
For vehicles with two axles, the 4S-4M system is the best choice. Forvehicles with three axles, the 6S-6M system is available. A compro-mise regarding system cost andperformance is achieved if not eve-ry wheel has a sensor, i.e. is not in-dividually controlled. Different ECUvariants are available for this pur-pose.
Vehicle 4 x 2 6 x 2 6 x 4 8 x 4ABS - System
4S - 3M front axle: MARrear axle: IR
4S - 4M
front axle: MIRrear axle: IR
front axle: MIR1st rear axle: IR2nd rear axle: second-ary control by sides
front axle: MIR1st rear axle: IR2nd rear axle: secondary control by sides
1st front axle: MIR2nd front axle second-ary control by sides1st rear axle: IR2nd rear axle: second-ary control by sides
6S - 4M – – front axle: MIRrear axles: MSR
front axle: MIRrear axles: MSR
6S - 6M6x2 ASR –
front axle: MIR1st rear axle: IR2nd rear axle: IR
front axle: MIR1st rear axle: IR2nd rear axle: IRwithout ASR function
front axle: MIR2nd front axle: second-ary control by sides 1st rear axle: IR2nd rear axle: IRwithout ASR function
6S - 6M6x4 ASR –
front axle: MIR1st rear axle: IR2nd rear axle: IRwithout ASR function
front axle: MIR1st rear axle: IR2nd rear axle: IR
front axle: MIR2nd front axle: second-ary control by sides1st rear axle: IR2nd rear axle: IR
System Design and Components ABS-D 3.
WABC
O
BASIC -
ABS44
6 004 ... 0
ALB
WABCO
BASIC - ABS446 004 ... 0
ALB
Fig. 2
10
4.2 Electronic Control Unit (ECU)
ABS / ASR System DescriptionABS-D4.
For the 4S/4M (4S/3M) system, anECU with 4 AMP Junior Power Tim-er plugs is used; for the 6-channelapplication, an ECU with 5 plugs isrequired. These plugs have been al-located to the power supply, the di-agnostic and dashboard connec-tions, and to the components of thecable harness for the wheels or ax-les.
For dimensions of the ECU’s hous-ing and the recommended fitting po-sition, please refer to the outlinedrawing (see Annex). Any water in-gress must be prevented. The ECUshould not be sited near any heatingelements.
For installation, either screws or arack (not shown) may be used. Dif-ferent variants are available fornominal voltages of 12 volt and 24volt.
Any voltage or ground problems re-garding the ABS-D ECU cause thewhole system to be switched off.
4.2.1 Description of warning lamp
A special transistor grounds thewarning lamp’s output, either tempo-rarily for bulb testing, or permanentlyif an error has been detected.
Test pulses check whether a load isconnected. Dimming of the bulb forreduced brightness must not bedone, especially not by switched
voltage supply, because bulbchecks might be affected and inter-preted as flash-code activation.
The bulb should have a maximum of5 W. The system is capable of de-tecting a defective bulb.
4. ABS / ASR systemdescription
4.1 CompatibilityThe D-Version is not compatiblewith any of the A-, B or C-Ver-sions because the cable harness
and plugs of the ECU have beenmodified.
11
v = 0 km/h
v = 7 km/h
ON
WARNINGLAMPON
OFF
WARNINGLAMP BLINKS
"IGNITION" on
actual faults : WARNING-LAMP ON
STREET-ABS
OFFROAD-ABS
WARNINGLAMPOFF
with stored sensor-fault orfirst time after fault clearance.
WARNINGLAMPON
OFF
In the normal mode (on-road ABS)the warning lamp goes off in keepingwith ECE R 13 Supplement 07 whilethe vehicle is stationary. The warn-ing lamp indicates defective sensors
detected when the ignition was firstswitched on.
It is possible that maintenance work(changing the lining) increases theclearance of the sensors becausethe workshop staff failed to re-adjustthem (pushing sensors home).
In order to prevent that the vehicle isdriven before this has been put right,WABCO recommends that the errormemory of the ECU is deleted whenmaintenance work has been done.This puts the ECU into its workshopmode. To leave this mode, thespeed signals received from allwheels have to be measured again.When this has been achieved suc-cessfully, the ECU will automaticallyreturn to the normal mode.
4.2.2 Function when igni-tion is switched on and vehicle is still stationary
4.2.3 Sensor input ports Different types of inductive sensorscan be connected. In order to pre-vent any interference potential, theinduced sinusoidal sensor voltage isfiltered.Different types of errors are detect-ed to permit selective deactivation.
Types of errors: interrupt and shortcircuit to ground or plus and crossedor wrong connections are detectedeven before the vehicle has movedoff and stored in the error memory. Dynamic sensor defects are detect-ed by analysing the signalling fre-quency (implausible signals such aserratic changes).To allow the ECU to detect anyclearance or wheel wobble on thebrake test bench, the ECU for the
D-version has been designed insuch a way that the peak-peak volt-age is measured and its highest andlowest readings stored in the RAMfor at least one wheel revolution.This is designed for the inspectionafter installation; the ECU should notbe disconnected from the system forthis purpose.It is important to know that the fil-tered sensor voltages may result indifferent values being measured us-ing an oscilloscope or a multimeter.In normal operation, measuring sup-ports the safety functions and helpsidentify any errors in the installation,such as excessive clearances,wrong installation of a pole wheel, ora soiled pole wheel.
ABS / ASR System Description ABS-D 4.
4.2.4 Grounding of output stage for modulators
Every solenoid is connected be-tween a switching (+) transistor andone of the two (diagonal) discon-necting (ground) transistors. This allows redundant interruption ofthe valve current, thereby ensuringthat a single defect does not cause
ABS to be switched off. If there is adefect inside the ECU, the system ispartially or fully shut down. The tran-sistors are checked periodically. Adistinction is made between partingof a cable and a defective outputstage.
12 1
4.2.5 Power output stage for modulators
The ECU concept is designed forbetween 3 and 6 modulators. Thevehicle manufacturer chooses oneof the different versions for the typeof vehicle in question. Connection ofa harness with a larger number ofmodulators causes the warninglamp to come on because the mod-ulator output port which is not pro-vided for is shorted to the warninglamp output port. Any cable har-nesses with fewer modulators thanthe number defined for the respec-tive system also causes the warninglamp to come on because the ab-sence of these components is per-ceived as a defect.
Defects which might cause the mod-ulator coils to be energized (transis-tor failure, external short circuit tobattery) are identified within 100 mil-liseconds and the corresponding di-agonal is switched off. Open circuitor short circuit conditions without ac-tive ABS control are identified within10 seconds causing wheels to beselectively switched off.
4.2.6 Controlling engine brake or retarder
4.2.7 ASR lamp
ABS / ASR System DescriptionABS-D4.
When ABS control is taking place, aswitching transistor connects the in-put port of the engine’s ECU or anexternal relay to ground. The tran-sistor is checked periodically with
the other output ports. The parame-ters set on the ECU determinewhether a parted cable can be de-tected.
While ASR control is taking place,the ASR lamp is used to indicate any
defects in the ASR components, de-pending on the parameters set.
The D-version ABS allows the ASRfunction to be shut off via a switch if
the parameters have been set ac-cordingly.
4.2.8 ASR shut-off
4.2.9 Output port of ASR lamp
A switching transistor supplies theASR lamp and briefly grounds theoutput port for testing. Test pulsescan now check whether a load isconnected. No dimmer may be usedto reduce the lamp’s brightness.
This particularly applies if a voltagesupply is connected. Dimming couldbe taken to mean that the flash codehas been activated.
4.2.10 Output port of ASR DIF brake
Depending on the speed and slipvalues, this function is supported byengine control. When both wheelsslip, the engine speed is reduced. Inthe event of any difference in thespeeds of the wheels on the drivingaxle, the ECU connects battery volt-age to the output port of the DIF
valve and applies the brake force viathe differential brake valve (DIF).
Parted cables can be detected auto-matically or by an appropriate facto-ry setting. Short to battery or groundis also detected.
131
4.2.11 Engine control
4.2.12 Neutral switch of transmission
On vehicles which do not have asynchromesh transmission, thespeed limiting facility via the PROPvalve is temporarily inhibited by thisinput signal in order to permit rev-
ving up for the purpose of changinggear. Any manipulation is perceivedand stored.
ABS / ASR System Description ABS-D 4.Different versions are provided with
q SAE J1939 (CAN),
q SAE J1922
q PWM on/off (EDC, E-GAS) and
q PWM for PROP valve
If the ECU of the ABS/ASR systemfinds a defect in engine control, thedifferential function is inhibited in or-der to prevent excessive strain onthe brakes.
In its original factory setting, theECU can be used both for ABS ap-plications only and for ABS withASR and/or an integrated speed lim-iting facility. In order to ensure prop-er operation for all applications, theECU stores any ASR componentsupon becoming aware of a ‘permis-sible system’ being used since itwas first installed. This happens assoon as the expected component isrecognized by the ECU connected.
The following systems have beendefined as permissible systems:
q A J1939/SAE interface by itself isan ABS component (i. e. retardercontrol) and is stored.
q A proportional valve by itself canbe one component of the speedlimiting facility. The system isstored as ‘permissible’ if the firstthreshold speed is less than thepreset value of 160 km/h
q A differential brake valve withone of the above-mentioned en-gine control systems means thatthis is an ASR system which isstored as such.
Other systems are not permissibleand are thus displayed as an ‘ASRconfiguration error’.
Previously installed componentscan be reset by means of a flashcode or other diagnostic equipment.This does not, however, apply to theproportional valve as a componentof the speed limiting facility (firstthreshold value less than 160 km/h).
4.3 Automatic recognition of periphery and setting of parameters for ASRand sustained-action brake (retarder)
4.3.1 Automatic learning function of the ASR component
14 1
4.3.2 Wheel sensors
ABS / ASR System DescriptionABS-D4.
stub axle
hub
Fig. 3: ABS sensor installation– front axle –
A wheel’s revolution is picked up bymeans of a pole wheel which turnswith the wheel, and a pulse-generat-ing sensor.
The inductive sensor (fig. 3) com-prises a permanent magnet, coreand coil. The magnetic flux sur-rounding the coil is cut by the rotat-ing motion of the toothed wheelinducing an AC voltage whose fre-quency is directly proportional to thewheel speed.
The WABCO sensor has been spe-cifically developed for the arduousconditions of commercial vehiclesuse. The sensor is held in positionby a special clamping bush madefrom corrosion-resistant spring ma-terial. This allows the sensor to bepushed up against the pole wheelduring assembly. No clearanceneeds to be set. The action of thebush also provides tolerance foraxle elasticity etc.
Fig. 3 shows a typical installation oftoothed wheel (1), clamping bush(2) and sensor (3) on a front wheel.In such an arrangement the clamp-ing bush should be mounted with atemperature-resistant and water-proof grease (e. g. silicone grease)in order to protect the hole in thesteering knuckle from corrosion anddirt. The toothed wheel is installed ina similar fashion on the hub of therear wheel. The sensor is securelymounted on the axle beam with aspecial stiff bracket.
The permissible range for the dy-namic tire circumference/toothnumber ratio is:
q 2.74 ... 3.68 mm/tooth on all ax-les (-15 ... + 15 % to standardtyre, see pole wheel spec.)
q 14% maximum deviation be-tween front, rear and third axle
This means:With a pole wheel with 100 teeth, thecircumference can be between2740 mm and 3680 mm if the axledeviation is < 14%.
To accommodate smaller tyre sizes,pole wheels with 80 teeth can beused. The range of permissiblewheel circumference can then bebetween 2190 mm and 2940 mm. Iffront axle and rear axles have differ-ent pole wheels or tyres, none of thecombinations may deviate from thetolerance range.
The sensor / pole wheel combina-tions generate signals with a fre-quency proportional to the wheelspeed. ABS / ASR computes wheelspeed and vehicle speed from thesesignals. Hub-type as well as minia-ture-type sensors or versions inte-grated in the bearings may be usedprovided they have been approvedby WABCO for the ABS/ASR appli-cation.
151
4.3.3 ABS solenoid valve
ABS / ASR System Description ABS-D 4.When control is not active, the inputpressure is passed on in full. Duringactive control the pressure is modu-lated according to the wheel behav-iour.
Several solenoid valve types areavailable.
The solenoid control valve, fig. 4,permits precise, graduated brakepressure modulation for ABS brakecontrol. It is usually mounted on theframe of the vehicle, or, in excep-tional cases, mounted on the axle. Itcomprises a double solenoid ar-rangement and two diaphragmvalves. The extremely fast-actingsolenoid valves merely affect the pi-lot chambers of the diaphragms.
These control the pressure in thebrake chamber by virtue of the valvegeometry.
The short reaction times and theABS functions
q pressure increase
q pressure hold
q pressure reduction
are basic requirements for a high
control performance while reducingair consumption to a minimum forABS-controlled braking and ASRoperation.
Pressure Increase
When not activated by the ECU ofthe ABS system, the diaphragm pilotchamber (2) of the inlet valve isopen to atmosphere. The brakepressure at port 1 lifts diaphragm 3and reaches the brake chamber infull through port connection 4. At thesame time, the brake pressure flowspast the non-energized armature (8)into diaphragm pilot chamber 6 andprevents the outlet valve from open-ing. When the driver reduces thebrake pressure, air flows from of thebrake chamber and back throughport 1. In certain conditions the out-let diaphragm is also opened whichallows the foundation brake to be re-leased quickly.
Pressure hold:
When the solenoid at 10 is ener-gized, brake pressure is admittedinto control chamber 2 via the clos-ing seal of armature 11. This causesthe diaphragm valve to close, sepa-rating connection 4 from port 1,thereby preventing any further pres-sure increase in the brake cylinder.
Pressure increase Pressure hold Pressure reduction
Fig. 4: Solenoid control valve
16 1
ABS / ASR System DescriptionABS-D4.
4.3.4 Extension cables for sensors and modula-tors
Pressure reduction:Both solenoids are energized in thepressure-reduction phase. The acti-vation of solenoid 10 as described in”pressure hold” causes the air sup-ply to be cut off. At the same time,solenoid 9 is energized so that thediaphragm control area of the outletvalve is evacuated to atmospherepast the seal of armature 6. Now thebrake pressure remaining in thebrake chamber reaches the seal ofdiaphragm 5 and is evacuated. Thisprocess is muffled.
The principles of design and func-tion of the solenoid control valvehave remained virtually unchangedin all four generations of WABCOABS systems (A, B, C and D ver-sions) for two- and multi-axle com-mercial vehicles.
In the meantime, nearly all Europe-an competitors have adopted a sim-ilar design for their solenoid valvesin an effort to achieve interchangea-bility. WABCO has also developedsolenoid valve variants for specialapplications. One such variant hasan adapter which can have a ”snor-kel” device fitted that gives the vehi-cle a wading capability. The sameadapter can also accept an exhaustsilencer when required.
ABS-valveDIN-Bayonet (left) 449 513 000 0
outline drawing, see Annex
from page 38 on
DIN-Bayonet (right) 449 514 000 0
M24x1 (left) 449 523 000 0
M24x1 (right) 449 524 000 0
ASR-valveDIN-Bayonet 449 515 000 0
M27x1 449 521 000 0
Sensor 449 751 000 0
To reduce the risk of installation er-rors WABCO offers different ver-sions of extension cables. The con-
nectors on the sensors / modulatorside are moulded.
171
Other Components ABS-D 5.
5. Other components
The components on the cab such asthe warning lamp, push-buttons etc.are widely known.
Regarding the cable harness, an im-portant point must be taken into ac-count:
The plugs of the ECU are AMP Jun-ior Power Timers.
For the cable harness of ABS D, ei-ther 4 or 5 connector housings mustbe provided.
and Junior Power Timer contacts for
4 channel 6 channel
WABCO No.AMP No.
894 110 091 4964 561 - 1 X X
WABCO No.AMP No.
894 110 092 4964 561 - 2 X X
WABCO No.AMP No.
894 110 093 4964 561 - 3 X X
WABCO No.AMP No.
894 110 094 4964 561 - 4 X
WABCO No.AMP No.
894 110 095 4964 561 - 5 X X
cable dimension WABCO AMP0.5 to 1> 1 to 2.5
mm2
mm2894 070 734 4894 070 829 4
927 779 - 3927 777 - 3
0.5 to 1> 1 to 2.5
PIN 15on 18 PIN plug
894 070 831 4894 070 832 4
927 771 - 9927 768 - 9
18 1
Other ComponentsABS-D5.
5.1 ASR components In addition to the ABS system com-ponents: sensor, solenoid controlvalve, ECU, warning lamp, Fig. 5shows the additional componentsfor drive-slip control (ASR) integrat-ed in ABS for commercial vehicleswith air brakes.
These are the ASR lamp whichshows the driver that the ASR modeis active and thus indicates that theroad surface is slippery, or that anASR component may be defective;the differential brake valve (8)which, when required, actuates thefoundation brake via a double checkvalve (7) for a wheel which may oth-erwise be spinning, the
q engine control cylinder (12) and
q the proportional valve (10)
which automatically control engineoutput to reduce engine power, irre-spective of driver control.
These engine components are notrequired if the vehicle in question isequipped with an electronic enginecontrol system which the ABS / ASRsystem ECU can communicate withvia a specific interface.
The ABS D versions have differentinterfaces which are also used forthe purpose of diagnostics. The fol-lowing defined interfaces are beinglooked at in more detail:
1) SAE J 1922
2) SAE J 1939
3) SAE J 1587
4) ISO 9141 Mode 8 (JED 677)
– SAE J 1922 This standard defines a local net-work for heavy-duty commercialvehicles with a maximum of 4electronic control units which ex-change data on the network.The electronic control unit for en-gine control has to begin itstransmission no later than 2 sec-
onds after ‘ignition on’. Other-wise the ABS control unit detectsan error and the ASR controlfunctions are inhibited. ASR en-gine control uses the ‘torque lim-iting mode’. The engine’s elec-tronic control unit should followthe torque limiting requirementswith a delay of no more than 150milliseconds.
The transmission rate, hardwareand protocol are defined in SAEJ 1922 and SAE J 1708.
Electronic control units with thisinterface only exist together withthe SAE J1587 interface used fordiagnostics. This type of inter-face with 10 kBaud has beenused for engines for years. SAEJ1922 will be replaced by theSAE J1939 interface.
5.2 Data interfaces
Fig. 5: 4-channel-ABS/ASR2-axle commercial vehiclewith rear-wheel drive (4 x 2)
191
Other Components ABS-D 5.– ABS/ASR functions
via J1922:retarder controlASR engine control
– SAE J 1939This standard defines an elec-tronic bus system on commercialvehicles (network). A commonabbreviation for this is CAN(Controller Area Network). Thismodern interface is used for ex-changing data at 250 kBaud be-tween the electronic control unitsof a vehicle.
– SAE J 1587 and ISO 9141 Mode 8These standards define the hard-ware requirements and the ex-change of data in terms ofdiagnostics. External or on-board diagnostics can beachieved with this standard.
– SAE J 1922The electronic engine interfaceuses pins 1 and 3 of the 17-pinplug.
WABCO supplies ABS control unitswith diagnostic interfaces toISO9141 or SAE J1587.ISO 9141 Mode 8 (bi-directionalmode) in combination with JED-677(WABCO works standard) definesthe exchange of diagnostic data be-tween the ECU and onboard or ex-ternal diagnostic equipment with anSAE J 1587 interface.The D version of ABS transmits asignal with an updating rate of500 ms. Any errors are automatical-ly transmitted via SAE J 1587 with-out any query.
Configuration if SAE J 1939 ver-sion is used
If signals are transmitted via theSAE J 1939 interface, the ECU rec-ognizes the system configurationwhich is then monitored during anyswitch-on phase. The connectionwith a proportional valve is detectedautomatically. If no parameter hasbeen set for the speed limiting value,any proportional valve without a dif-ferential brake valve is perceived asan error. The differential brake valvewithout one of the above interfacesalso causes an error to be reported.
The differential brake valve, togeth-er with one of the above interfaces,
defines the parameter (stored sys-tem) ”ASR permitted”. If the outputof the differential brake valve de-tects an electrical load, it sets theparameter (stored system) ”lookingfor parted cable active”.
All components are detected auto-matically and added to the systembeing monitored. Only valid ASRsystems are stored.The retarder relay is always stored.ASR without a differential brakefunction (engine control only) re-quires special parameters to be set.The same applies to simulating dif-ferential lock (differential brake func-tion without engine control).
SAE J 1587 versionsThe standard ABS version for theSAE diagnostic system to SAE J1587 is available at present with theengine interfaces to
q SAE J 1922 interface version or
q SAE J 1939 (CAS) interface ver-sion
in 12 and 24 volt types.
5.3 Diagnostic interfaces
20 1
Other ComponentsABS-D5.If the ABS control unit is being re-placed on a vehicle that has noASR, the following must be takeninto account:
Interface Control / Function
ABS without
DBR relay sustained-action brake on/off
SAE J1922SAE J1587
– control retarder moment– status message (dashboard)
SAE J1939 (CAN) – control retarder moment– wheel speed message– status message (dashboard)
ABS+ASR (ATC) DIF + SAE J1922 additional differential brake and engine control
DIF + SAE J1939(CAN)
see above
spare part on vehicle with
desired system on vehicle
engine / retarder interface
DIFF brake recogni-tion
comments
ABS interrupt interrupt 1) permitted
ABS + SAE J1922 interrupt interrupt 2) 1) accepted, ABS interface is stored once recognized
ABS + SAE J1939 interrupt interrupt 2) 1) accepted, ABS interface is stored once recognized
ABS + DIF + SAE J1922 interrupt connected error 3)
ABS + DIF + SAE J1939 interrupt connected error 3)
ABS + DIF + SAE J1922 connected interrupt accepted (ABS + SAE J1922)
ABS + DIF + SAE J1939 connected interrupt accepted (ABS + SAE J1939)
DBR relay (retarder) DBR load interrupt 4) storage of load once recognized, irrespective of ASR
Please note: 1) filament test, ASR-L on for shorter than ABS: no ASR
2) parted cable recognition if interface / load was recognized previously.
3) ASR configuration.
4) sustained-action brake relay (DBR) cable break if relay was recognized previously.
211
Other Components ABS-D 5.
spare part on vehicle with
desired system on vehicle
engine / retarder interface
DIFF brake recogni-tion
comments
ABS (v-limit = 160) interrupt interrupt 1) permitted
ABS + SAE J1939 interrupt interrupt 2) 4) accepted, ABS interface is stored once recognized
ABS + PWM in / outv-limit < 160 km/h
interrupt interrupt 5) 4) accepted, ABS interface is stored once recognized
ABS + PWM in / outv-limit = 160 km/h
interrupt interrupt 4) recognized PWM interface is not stored but 4)
ABS + GBPROP < 160 km/h interrupt interrupt error 3) 1) end-of-production line / service
ABS + DIF + SAE J1939 interrupt error 4).
ABS + DIF + PWM in / out interrupt error 4) irrespective of v-limit
ABS + DIF + GBPROPv-limit < 160 km/h
interrupt error 3)
ABS + DIF + GBPROPv-limit = 160 km/h
interrupt error 4)
ABS + DIF + SAE J1939 interrupt accepted (ABS+SAE J1939)
ABS + DIF + PWM in / outv-limit < 160 km/h
interrupt accepted (ABS + PWM in / out)
ABS + DIF + PWM in / outv-limit = 160 km/h
interrupt error 4)
ABS + DIF + GBPROPv-limit < 160 km/h
interrupt accepted (ABS + SL)
ABS + DIF + GBPROPv-limit = 160 km/h
interrupt error 4) v-limit parameter must be set
WABCO standard setting for v-limit = 160 km/h (see ECU product spec.)
DBR relay (Retarder) DBR load inter-rupt
5) storage of load once recognized, irrespective of ASR
Please note: 1) filament test, ASR-L on for shorter than ABS: no ASR
2) cable break recognition if interface was recognized previously.
3) cable break
4) ASR configuration
5) sustained-action brake relay (DBR) cable break if relay was recognized previously.
22 1
Other ComponentsABS-D5.
5.4 Diagnostic functions
Any errors detected are immediatelystored in a non-volatile memory.
The system’s reactions depend onthe type of error detected. Selectiveshut-down is not changed until ‘igni-
tion on’. Any errors relating to an in-terface are deleted as soon as datacan again be exchanged via that in-terface.
5.4.2 Automatic deletionerror markingerror readout
An error which has been stored isdeleted automatically if this compo-nent does not show any renewed er-ror for 250 hours (resolution 1 h).
Benefits of automatic deletion:q The error memory is then empty
if errors created during vehiclemanufacture or maintenancewere not deleted (although WA-BCO recommends to clear theerror memory after production).
Numbers marking errorsNumbers which mark errors are usedin accordance with SAE J 1587
which standardises the numbers forthe components which a part of thesystem (SID = Subsystem Identifier),provides another number for differenterror types (FMI = Fault Mode Identi-fier). A number for the error frequen-cy is also stored and read out viadiagnostics.
Error readout
Using diagnostic equipment, infor-mation on errors and defects can beread out and deleted. The timecounter for automatic deletion canbe read out and reset.
The error memory section of theEEPROM comprises 16 error ad-dresses. It is used like a stack. If theEEPROM is empty initially, the firsterror is stored at the first address,the second error at the second ad-dress, etc. Similar errors do not re-quire a new address; they incrementthe respective counter values. Up toaddress 8, different errors applica-ble to the same component (SID)can be stored.
In order to prevent that one or sever-al defective components fill the
whole area of the error memory, thestorage of errors in addresses 9 to16 is different. In this area, only onedefect per component may bestored. In addition, every error ad-dress has a time counter which re-turns to its original setting when theerror address is being set. When alladdresses are occupied, any newerror is stored at the address whosetime counter shows the highest val-ue (longest time without any repeti-tion). Information pertaining to thefinal 4 addresses are stored irre-spective of error repetition.
5.4.1 Organisation of error memory
5.4.3 Functional testing by diagnostics
By addressing only one modulatorper diagnostics and measuring thebrake force or pressure, any mix-upin the area of the valves and anyleakage of an inlet valve can be de-tected. Leakages of the outlet valvecan be detected like any other leak-age within the braking system.
The ECU is unable to distinguish be-
tween 12 volt and 24 volt relays ormodulator coils. Their resistance de-pends on the actual temperature.The maximum tolerance for 12 voltcomponents with a maximum tem-perature and the minimum tolerancefor 24 volt components with a maxi-mum temperature at -40°C couldshow the same readings. Integratedresistance measurement would also
231
Other Components ABS-D 5.have to take into account the widerange of voltages.
WABCO recommends to measurethese components and the resist-ance of the sensor insulation at leastwhile the vehicle is being manufac-tured (cab, axles).
By turning only one wheel and read-ing out the wheel speed, the properallocation of sensors can bechecked.
Any run-out deviation of the polewheel and the clearance betweensensor and pole wheel can be com-puted by reading out the analoguevalues of the minimum and maxi-
mum voltages of the sensor. For thispurpose it is necessary to turn thewheel at a consistently slow speed,and the size of the pole wheel mustbe known.
The output voltage of the sensor de-pends on the clearance and the sizeof the pole wheel. The monitoring fa-cility integrated in the ECU takesinto account any excessive clear-ance in combination with small polewheel sizes. In production, theclearance between the sensor andthe pole wheel should be set proper-ly. WABCO offers different types ofequipment for testing after final as-sembly.
5.4.4 Flash code To activate the flash code, the warn-ing lamp or the ASR lamp has to begrounded for a certain time by push-ing a button. The type of lamp useddepends on the type of ECU or theparameters set for it. The length oftime the push-button is held downdetermines the mode. After releas-ing that push-button, the lamp is onfor another 0.5 second to confirmthat the push-button has been rec-ognized and that the ECU has ac-cepted stimulation of the flash code.Electronic Control Unit = ECU.
If an error is perceived, or if the lampis grounded for longer than 6.3 sec-onds, the flash code is ended. If theflash code is stimulated (via thewarning lamp) for longer than 15seconds, a warning lamp defectmight be perceived.
Testing equipment that groundsall dashboard lamps activates theflash code. ABS ECUs for suchvehicles usually inhibit the flashcode.
24 1
Other ComponentsABS-D5.
Diagnostic mode:
FC: error code // 1 to 8 // a: first part; b: second part see flash code list, page 27FC1 is repeated continuously if theerror was detected after the ECUwas switched on.If an error is detected during the ”ig-nition on” phase (current error), thisis flashed out. If several errors weredetected within that phase, only thelast one is flashed out. To end theflash code, the ignition has to be
switched off and then on again, orthe vehicle has to move off (speedmeasured on more than one axle).
If no current fault is detected, thelast fault detected is the first one tobe flashed out. Any subsequent indi-cations may not show the errors inthe order in which they occurred.The flash cycle ends when the lastone of the errors stored has beenflashed out.
FC: error code // 1 to 8 // a: first part; b: second part
see flash code list, page 27
Flash code timing:
The system mode is activated if thepush-button was pressed for be-tween 3 and 6.3 seconds. All errorsstored are deleted only if there iscurrently no error. To end the flashcode, the ignition has to be switchedoff and then on again, or the vehicle
has to move off (speed measured onmore than one axle).The system code (a number) showsthe system expected by the ECUand should be used to verify that theright ECU version is being used.
5.4.4.1System mode: deleting errors stored:
In order to activate the diagnosticmode, the push-button has to be
held down for between 0.5 and 3.0seconds.
251
Other Components ABS-D 5.After activating the system mode,ASR (ATC) is inhibited to preventASR (ATC) errors being detected onthe roller dynamometer and to per-mit higher differences in the speedsof the driving and steering axles. Ifan ECU is used which provides forstimulation of the flash code via thewarning lamp, the ASR (ATC) lampcomes on to show that ASR (ATC)has been inhibited.
Two seconds after the system modehas been activated, other functionsare possible:
1. ASR (ATC) engine control canbe tested by pressing the push-button twice for
> 0.5 sec [ASR(ATC) reducesthe engine torque for 10 sec.].
2. A recognized ASR (ATC) or re-tarder system can be reset(reconfiguration) by pressing thepush-button three times > 0.5sec. (the absence of componentsis confirmed). Reconfiguration isconfirmed by four brief flashingpulses.
No current error: DELETION OF ALL ER-RORS STORED
Deletion is confirmed by 8 briefflashing pulses; this is followed bythe system code being flashed out.
Current error:like ”no current error”,
”DELETION OF ALL ER-RORS STORED” is notpossible.
Systems:1 X 6S/6M (6x2 ASR) 6 X 4S/3M (VAR rear)2 X 4S/4M 7 X 4S/2M (VAR both)3 X 4S/3M (MAR/VAR front)4 X 6S/4M5 X 6S/6M (6x4 ASR)
26 1
Other ComponentsABS-D5.
5.4.4.2 Functional testing of engine control
After pressing the push-button twomore times, the ABS/ASR ECUcauses the engine to idle for 10 sec-onds. The push-button has to be ac-tuated twice for longer than 0.5seconds, and the interval between
actuations must be shorter than 3seconds. The 10 seconds begin 3 seconds af-ter the last actuation. At the sametime, the system code is beingflashed out.
5.4.4.3 Reconfiguration q The ECU changes its basic set-ting (without ASR/ATC) to ABS/ASR(ATC) if a differential brakevalve and engine control havebeen detected.
q Once an SAE J1939 (CAN) inter-face has been detected withouta differential brake valve, this in-terface is monitored as an ex-tended ABS component.
q Once a sustained-action brakerelay (DBR outlet) has been de-tected or a retarder message re-ceived from the SAE J1939interface (irrespective of param-eter setting), this is also storedand monitored.
Unless it has been subject to recon-figuration, an ECU with an extended
monitoring feature cannot be usedon a vehicle that does not containthese components. Diagnosticequipment or the flash code can beused for reconfiguration.
To prevent unintentional reconfigu-ration, this function must be con-firmed by pressing the push-buttonthree times, as described above forfunctional testing of engine control.Before the system code is flashedout, 4 brief flash pulses confirm thatthe parameters are being changed.
The length of the ASR/ATC filamenttest shows whether the configura-tion includes ASR/ATC: no ASR/ATC - 1.5 sec., with ASR/ATC 3 sec.(similar to warning lamp).
271
ABS-D 5.Other Components
5.4.4.4Flash code list
Roller dynamometer function:
On some roller dynamometers it isnecessary to inhibit ASR/ATC topermit higher differences in thespeeds between the driving axle andthe steering axle. By activating thesystem mode, ASR/ATC is inhibited.If the flash code via the warninglamp is used, the ASR/ATC lampcomes on to indicate that ASR/ATChas been inhibited.
In order to prevent hazardous situa-tions caused by brake force after ig-nition off/on, ASR/ATC is inhibitedas long as there is such a differencein speeds after switching on the igni-tion. If this is the case, the ASR/ATClamp will be on.
On vehicles without ASR/ATC, thedetection of some errors is inhibited.
First part of error code(FC. a)
Second part of error code(FC. b)
1 NO ERROR 1 NO ERROR2 ABS MODULATOR3 SENSOR CLEARANCE4 SENSOR short circuit/ interrupt5 SENSOR defective / tyre size6 SENSOR POLE WHEEL
1 FRONT RIGHT2 FRONT LEFT3 REAR RIGHT
4 REAR LEFT5 3rd AXLE RIGHT6 3rd AXLE LEFT
7 SYSTEM FUNCTION 1 DATA CONNECTION 2 ASR VALVE3 SUSTAINED ACTION BRAKE
RELAY4 WARNING LAMP5 ASR CONFIGURATION6 ASR PROP/DIF LOCK/
STOP VALVE8 ECU 1 UNDERVOLTAGE
2 EXCESS VOLTAGE3 INTERNAL DEFECT4 CONFIGURATION ERROR5 GROUND CONNECTION
28 1
ABS-D5. Other Components
Error code Repairinstructions
2 . n Check modulator cable. Inlet (IV) or outlet (OV) or joint cable is continuously or temporarily disconnected to shorted to ground or plus.
3 . n Amplitude of sensor signal is too low. Check wheel bearing clearance, wheel wobble, push sensor in further. Check sensor wiring and plug-in connections for intermittent contact. Another possible cause: gear was engaged on slippery road surface causing a driving wheel to slip for 16 seconds.
4 . n Check sensor cable. Interrupt, short to plus or ground or between cables IG/IGM has been detected.
5 . n Check sensor cables and plugs for intermittent contact. Check pole wheel for any damage. Check if cables of two sensors have been confused.Tyres or number of teeth on pole wheel are different.
6 - n Check pole wheel for any damage, missing teeth. Check for wobble. Check using WABCO Sensor Probe. Replace pole wheel as required. If clearance errors have also been stored, adjust the clearance (pushing in the sensor).
7 -1 ECU with PROP: Check cable and speedometer signal. C3/B7 signal calibration,check tyre sizes. gear lever shows ”neutral” or has been manipulated.
Electronic engine control: check interface wiring or other ECUs.High slip / dynamometer? One axle was much faster than others?
7 -2 Check cable. Output interrupt or shorted to ground or battery voltage.
7 -3 Check cable. Output interrupt or shorted to ground or battery voltage.ECU with SAE J1922 or SAE J1939: Check other ECUs. No communication via interface.
7 -4 Check cable and bulb. Was flash code button pushed down for longer than 16 sec?
7 -5 Check cable and parameters. A differential brake valve has been detected but no engine control feature. If ”ASR self-learning” is inhibited, engine control feature CAN, PWM, PROP has been detected.
7 -6 Check cable. Output interrupt or shorted to ground or battery voltage.
8 -1 Check voltage supply and fuses. Supply voltage is too low at times.
8 -2 Check generator and battery. Supply voltage was too high for longer than 5 sec.
8 -3 Replace the ABS (ASR) ECU if the error occurs repeatedly.
8 -4 Wrong ECU or wrong parameter settings on the ECU.
8 -5 Check ECU ground wiring and shared valve lines IV/OV.
29
6. Installation Some comments on installation:
Circuit schematic 841 801 277 0 onpage 33 shows a 4S/4M-ABS/ASRsystem on a vehicle moving from leftto right.
The 18-pin plug is provided for driv-er’s cab functions and connected tothe warning lamp, power supply, etc.
The circuit schematic for 6S/6M isincluded in the Annex.
The solenoid valve and the sensoron the left-hand side of the front axleare connected to the 6-pin plug.
The 9-pin plug comprises the right-hand side of the front axle, the signalfor a proportional valve and the C3input port (speedo).
The 15-pin plug connects the rearaxle components including the ASRsolenoid valve.
6.1 Important for installation
If the ABS valve is to be mounted onpart of the steel frame which has notbeen surface-treated, the holesused to fasten the valve should bedeburred and treated with a protec-tive coating to prevent contact corro-sion.
The output port (3) must point down-wards. There must be a distance of50 mm between the vent and anyadjacent components to allow thepressure to escape.
The product specifications for the in-dividual components must alwaysbe adhered to.
Grease must be used for fittingbush and sensors.Approved types of grease:
Staborags NBU (1 Kg) 830 502 063 4
5 g tube 068 4
Complete Sensor Set ... 578 0(clamping bush + grease)
441 032 921 2
Complete Sensor Set ... 579 0(clamping bush + grease)
441 032 922 2
Installation ABS-D 6.
30
ABS-D
311
ABS-D 7.
Annex
32
Circuit Schematic 841 801 277 0ABS-D7.
33
Circuit Schematic 841 801 278 0 ABS-D 7.
34
Bremsschema 841 000 401 0ABS-D7.
35
Brake Diagram 841 000 402 0 ABS-D 7.
36
Brake Diagram 841 000 403 0ABS-D7.
37
Cable for ABS Solenoid Control ValvePlug “DIN Bayonet“
ABS-D 7.
38
Cable for ABS Solenoid Control ValvePlug “DIN Bayonet“
ABS-D7.
39
Cable for ABS Solenoid Control ValvePlug “M 24x1“
ABS-D 7.
40
Cable for ASR Valve Plug “DIN Bayonet“
ABS-D7.
41
Cable for ASR ValvePlug “M 27x1“
ABS-D 7.
42
Sensor Extension CableABS-D7.
43
Inductive Sensor with Socket ABS-D 7.
44
Electronic 446 004 311 0ABS-D7.
45
Electronic 446 004 404 0 ABS-D 7.
46
Electronic 446 003 404 0ABS-D7.
47
Solenoid Modulator Valve ABS-D 7.
48
