ABS LAND ROVER FRELANDER 2 2006 Manual PDF
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ItemPart NumberDescription
1-Retai ni ng s crew2-W heel s peed s ens or
3-Beari ng seal and magneti c encoder ri ng
4-W heel bearing5-W heel hub
An acti ve wheel s peed s ens or is ins tall ed in each wheel knuckle, and provides t he ABS module wit h a rotat ional speeds ignal from each road wheel. The head of each wheel s peed sens or is pos it ioned clos e t o a magneti c encoder incorporat edint o t he s eal of t he wheel beari ng. Each front axl e beari ng encoder contai ns 44 north and s out h poles ; each rear axlebearing encoder contai ns 48 pol e pairs . A fl y l ead connect s each sens or to the vehicle harnes s .
The wheel s peed s ens or is suppli ed wit h a power s upply and a si gnal connecti on from the ABS modul e. W hen the ignit ions wit ch is i n power mode 6 (ignit ion), the ABS modul e s uppl ies power to the wheel s peed sens ors and moni tors the ret urns ignals . Rotat ion of t he wheel s induces current fl uct uati ons i n t he s peed sens or return s ignals . The ABS modules ubs equent ly convert s the return s ignals i nto individual wheel s peeds , and t he overall vehi cl e s peed.
The ABS module out puts t he i ndi vi dual wheel speeds , and vehicle s peed on the hi gh speed CAN bus for use by others ys t ems . The qual it y of the vehicle speed s ignal is al so broadcas t on t he high s peed CAN bus . If all wheel s peed s i gnal sare avail able t o calculate vehi cl e s peed from, the quali ty of t he vehicle s peed s ignal is s et t o 'data cal cul at ed wi thi ns pecified accuracy'. If one or more wheel s peed s ens ors are i noperati ve, t he qual it y of the vehicl e s peed s i gnal is set t o'accuracy out s ide s peci fi cat ion'.
The ABS module monit ors t he wheel s peed s ens or circuit s for fault s . If a fault i s det ected t he ABS module st ores a rel at edDTC i n memory and il lumi nat es t he appropriat e warni ng indicator l amps, dependi ng on t he s ys t em funct ions affect ed(DSC/ETC, ABS, EBA/EBD, HDC). A warni ng chi me i s als o s ounded to al ert t he dri ver t o t he faul t condit ion.
For vehicles ins tall ed wit h a high-l ine i ns t rument clus ter, a mes s age is di spl ayed in t he mes sage center, onl y if t he faul taffect s t he HDC funct ion.
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For addit ional informat ion, refer t o:
Ins trument Clus ter (413-01 Ins t rument Clus t er, Descripti on and Operat ion),Informat ion and Mes s age Cent er (413-08 Informati on and Mes sage Cent er, Descripti on and Operat ion).
As t he wheel s peed s ens ors are acti ve devi ces , a return s ignal is availabl e when t he road wheels are not rot ati ng. Thisenabl es the ABS modul e t o check t he condi ti on of the s peed s ens ors whil e the vehicl e is st ati onary.
SENSOR CLUSTER
ItemPart NumberDescription
1-Sens or clus ter
2-Retaini ng s tud and nut (2 off)3-Electrical connect or
The s ens or clus ter is ins tal led beneat h t he cent er cons ole and i s s ecured to the t rans mi ss i on tunnel wit h 2 s t uds and nut s .The s ens or clus ter is a compact unit t hat provides t he ABS module wi th inputs of yaw rate, roll rat e, longit udi nal andlat eral accelerat ion. The ABS module broadcas ts the i nput values on the hi gh speed CAN bus for use by other s ys t ems .
W hen t he i gni ti on is i n power mode 6 (ignit ion), the s ens or cl us t er recei ves an ignit ion power feed from t he ABS module.The s ens or clus ter is als o connected t o t he ABS module via a privat e CAN bus .
The s ens or clus ter is diagnos ed by t he ABS module. If a s ensor faul t is det ect ed t he ABS module s t ores a relat ed DTC inmemory and il lumi nat es t he appropriat e warni ng indicator l amps, dependi ng on t he s yst em funct ions affect ed (DSC/ETC,ABS, EBA/EBD, HDC). A warning chime is al s o s ounded t o alert the driver to the fault condi ti on.
For vehicles ins tall ed wit h a high-l ine i ns t rument clus ter, a mes s age is di spl ayed in t he mes sage center, onl y if t he faul taffect s t he HDC funct ion.
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For addit ional informat ion, refer t o:
Ins trument Clus ter (413-01 Ins t rument Clus t er, Descripti on and Operat ion),Informat ion and Mes s age Cent er (413-08 Informati on and Mes sage Cent er, Descripti on and Operat ion).
STEERING WHEEL MODULE
ItemPart NumberDescription
1-St eering wheel module2-Cl ocks pring and s t eering angle s ens or
The s teeri ng wheel modul e cont ains t he s teering angle s ens or, clocks pri ng and s teering col umn mul ti functi on s wit ches t oform an int egral component . The s teeri ng angle s ensor i s connected di rectl y to the cl ocks pring.
The s teeri ng wheel modul e is mount ed t o t he upper s t eering column wit h 2 s crews , and receives an elect rical s uppl y fromt he main harnes s vi a a 4-pi n connector l ocat ed on t he si de of the uni t. The module provides t he locati on and elect ricalconnecti on for t he 2 mul ti functi on swit ches .
Input s ignals from t he s teeri ng angl e s ensor are received and process ed by t he s teering wheel modul e t o calculate thes teeri ng wheel angle, and s t eering wheel angl e s peed. The i nformat ion is t rans mit t ed on the hi gh s peed CAN bus for us eby t he ABS module.
Steering Angle Sensor
The s teeri ng angle s ensor i s connected t o t he s teering wheel wit h 2 dowels . The s teering angle s ens or moni tors s teeri ngwheel rotat ion, and provides i nformat ion of t he s teering wheel angl e and rat e of s peed of s t eering wheel movements .
A code wheel and 16 opt ical digit al sens ors are ins t al led i nsi de t he s teeri ng wheel angle sens or. Rotat ion of t he code
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wheel i s read by the opt ical-di git al s ens ors t o produce s teeri ng wheel rotat ional speed s ignals . The s teering angle s ens oris abl e t o meas ure a rot at ion range of +/- 720 degrees , alt hough t he s teering mechani s m wi ll only al low the s t eeringwheel t o rotat e a maxi mum of +/-540 degrees .
Signals from t he st eeri ng angl e s ens or are trans mi tt ed on t he vehicle hi gh s peed CAN bus , and received and proces sed byother s yst ems s uch as DSC. The trans mi tt ed i nformat ion i ncl udes det ails of st eering wheel angle and s t eering wheelrot ati onal s peed, along wit h s ignal i ntegri ty informati on.
If a fault occurs wi thi n t he st eeri ng angl e s ens or, a DTC wi ll be s et and s tored in t he s teering angle s ens or memory. Thes teeri ng angle s ensor faul t is al s o s tored in the ABS modul e memory that i lluminates t he appropri at e warning i ndi cat orlamps , depending on the sys tem functi ons affect ed (DSC/ETC, ABS, EBA/EBD, HDC). A warni ng chi me i s als o s ounded t oalert the driver to the fault condi ti on.
For vehicles ins tall ed wit h a high-l ine i ns t rument clus ter, a mes s age is di spl ayed in t he mes sage center, onl y if t he faul taffect s t he HDC funct ion.
For addit ional informat ion, refer t o:
Ins trument Clus ter (413-01 Ins t rument Clus t er, Descripti on and Operat ion),Informat ion and Mes s age Cent er (413-08 Informati on and Mes sage Cent er, Descripti on and Operat ion).
The s teeri ng angle s ensor and ABS modul e are abl e t o be i nt errogat ed us ing t he Land Rover approved diagnos t icequi pment.
Clockspring
The clocks pri ng is a rot ary coupling that provides t he electrical connect ion bet ween the fixed s t eering wheel module, andt he st eeri ng wheel mount ed cont rols and Supplement al Res t raint Sys tem (SRS) dri ver's ai rbag.
A colored indicator i s provided wi thi n the cl ocks pring and is vis i bl e t hrough a t rans parent pers pex cover when the s t eeringwheel i s removed, and t he st eeri ng angl e s ens or is aligned t o t he cent ral posi ti on. The indicator makes s ure t he s teeringangl e s ensor and s t eering s ys tem are correct ly al igned fol lowi ng repairs t o the st eeri ng mechanis m.
Service Information
Before s eparat ing the s t eering component s from the connect ing s t eering column, t he clocks pri ng mus t be ali gned to thecent er pos i ti on (i ndi cat or vi s ible) and t he wheels point ing s t raight ahead. The clockspring i s ret ained i n the cent ralposi ti on wit h a locki ng s crew.
INSTRUMENT CLUSTER INDICATOR LAMPS
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ItemPart NumberDescription
1-Brake warni ng indi cat or l amp – al l except Nort h American Specificati on (NAS)2-ABS warni ng indicator l amp
3-Brake warni ng indi cat or l amp - NAS vehicl es
4-HDC warning i ndi cat or lamp (low li ne ins trument cl ust er)5-DSC warni ng indicat or l amp
6-HDC i nformat ion indicator lamp
The ins t rument clus ter cont ains 2 types of indicator lamps to di s pl ay the operat ing st atus of t he s elected ant i-lock cont rol- s tabil it y as si s t functi ons . The indicat or l amps provide a vis ual not ifi cat ion of ei ther a s yst em warning or i nformat ionindicat ion t o t he dri ver. There are 4 indicat or l amps on vehicles wi th a high-l ine inst rument clus t er; 5 i ndi cat or lamps onvehi cl es wit h a low-line ins trument cl us t er.
The fol lowing ant i-lock cont rol - s t abi li ty as s is t indicat or l amps are ins tall ed in the ins trument cl us t er:
ABS warni ng indicat or l ampBrake warning i ndi cat or lampDSC warni ng indi cat or l ampHDC warning i ndi cat or lampHDC i nformati on indicator l amp.
For addit ional informat ion, refer t o: Ins t rument Clus ter (413-01 Inst rument Cl us t er, Des cript ion and Operat ion).
ANTI-LOCK BRAKE SYSTEM MODULE
The ABS module cont rols the brake funct ions by operat ing t he HCU to modul at e hydrauli c pres s ure t o t he indivi dual wheelbrakes.
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The ABS module is at tached to the HCU and forms an i ntegral component . A 47-pi n connector provides t he electricalint erface bet ween the ABS modul e and t he vehi cl e wi ri ng. The ABS modul e may be i nterrogated us ing the Land Roverapproved diagnos t ic equipment.
HYDRAULIC CONTROL UNIT
The HCU i s a 4 channel uni t that modulat es the s upply of hydrauli c pres sure t o t he brakes , under the control of t he ABSmodule.
The mas ter cylinder pri mary and secondary circuit out let s are connect ed to the HCU pri mary and secondary circuit s .For addit ional informat ion, refer t o: Hydraulic Brake Actuati on (206-06 Hydraulic Brake Act uati on, Des cri pt ion andOperat ion).Each of t he HCU ci rcuit s cont ains t he fol lowing components t o control t he s uppl y of hydraulic press ure to the brakes :
A normally open, s olenoid-operat ed pil ot val ve, t o enabl e acti ve braking.A normally cl osed, s olenoid-operat ed pri ming val ve, t o connect the brake fl uid reservoi r to the dual ci rcuit hydrauli cpump duri ng act ive braki ng.A hydrauli c pump, to generat e hydrauli c pres sure for act ive braking and return brake flui d to the res ervoir.Normal ly open, s ol enoi d-operat ed inlet valves and normal ly cl os ed, s ol enoi d-operat ed out let valves , to modul atet he hydraul ic pres s ure in t he i ndi vi dual brakes .An accumul ator and a relief valve, to allow the fas t rel eas e of pres s ure from t he brakes.Fil ters , t o prot ect t he i nt ernal components from contami nat ion.
The pri mary ci rcuit als o i ncorporates a pres sure s ens or t o provide t he ABS modul e wit h a hydraul ic pres s ure si gnal .
Contact pins on t he HCU mat e wi th cont act s on t he ABS module to provi de t he electrical connect ions from the ABS modul et o the dual circui t hydraul ic pump motor, and t he pres s ure sens or. The s olenoids t hat operat e t he val ves are i nst all edwit hin the ABS modul e.
HCU Schemati c Diagram
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25-Sol enoi d-operated inlet valve (LH rear brake)
26-Sol enoi d-operated inlet valve (RH front brake)
The HCU features 3 operati ng modes:
Normal braki ng/ EBDABS brakingActi ve braking.
Normal Braking/EBD Mod e
Ini ti ally, all of t he s olenoi d-operat ed val ves are de-energi zed. Operat ing the brake pedal produces a corres pondi ngincreas e or decreas e of press ure in t he brakes , through t he open pil ot val ves and i nlet valves. If t he ABS moduledetermines t hat EBD is necess ary, i t energi zes the i nlet valves for both the rear brakes , t o i sol at e t he brakes from anyfurther increas e i n hydraulic press ure.
• NOTE: Only the rear brakes are control led by the EBD funct ion.
ABS Braking Mode
If the ABS modul e determines t hat ABS braking i s neces sary, it energizes t he inl et and out let valves of the relat ed brakeand s tarts t he hydrauli c ret urn pump. The i nl et val ve cl oses to i s ol ate the brake from pres s uri zed flui d; the out let valveopens to releas e pres s ure from the brake int o t he accumulat or, and t he ret urn pump ci rcuit . The reduced hydraul ic pres s ureall ows the wheel t o accelerate. The ABS module then operat es the i nlet and outl et val ves t o modul at e t he pres s ure i n t hebrake t o apply t he maximum braking effort wit hout locki ng the wheel . Cont rol of the val ves for each wheel takes placeindivi dual ly.
Active Braking Mode
The act ive braki ng mode i s us ed to generat e and control hydrauli c pres s ure t o t he brakes for funct ions other t han Normaland ABS braking, for example RSC, DSC, EBA, ETC, HDC.
For act ive braking, t he ABS module energi zes the pi lot valves and pri ming valves , start s t he ret urn pump and energizes allof the inlet valves. Brake fl uid, drawn from t he res ervoir t hrough the mast er cyl inder and priming valve, is press uri zed byt he ret urn pump and suppli ed to the i nlet valves. The ABS modul e t hen operat es t he inl et valves and out let val ves , asrequired, to modul at e t he pres s ure i n t he indivi dual brakes . Some noi s e may be generat ed during act ive braki ng.
Service Information
The ABS module compris es an HCU and an Elect roni c Cont rol Unit (ECU) t hat mus t not be s eparated. The ABS module andHCU as s embly i s s uppl ied as a si ngl e component and arrives i n a pre-fill ed s tat e.
• NOTE: The ABS module, HCU and the s ens or clus t er are fragil e components and mus t be dis carded if dropped ordamaged.
CONTROL DIAGRAM
• NOTE: A = Hardwi red; D = Hi gh Speed CAN bus ; N = Medi um Speed CAN bus ; U = Pri vat e CAN bus
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ItemPart NumberDescription
1-Ins t rument clus ter2-Steeri ng wheel modul e (st eeri ng angl e s ens or)
3-Speed control ‘+' and '-‘ swit ches
4-RH s t opl amp5-LH s topl amp
6-High mount ed s toplamp
7-ABS module8-HDC s wi tch
9-DSC s wit ch
10-LH rear wheel s peed s ens or11-RH front wheel speed s ensor
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12-LH front wheel s peed s ens or
13-RH rear wheel s peed sens or
14-Act ive On-Demand Coupling modul e15-ECM
16-Diagnost ic socket
17-Sens or clus ter18-Terrai n Res pons e™ control modul e
19-Trans mis s ion Cont rol Modul e (TCM) - aut omati c t rans mis s ion models onl y
20-CJB
PRINCIPLES OF OPERATION
Anti-Lock Brake System
ABS cont rol s t he s peed of all road wheel s t o ensure opti mum wheel s li p when braking at the adhesi on li mit . The wheelsare prevent ed from locki ng to ret ai n effecti ve st eeri ng cont rol of the vehicle.
The front brake pres s ures are modul ated s eparat el y for each wheel. The rear brake press ures are modulat ed by s elect low.Select low appli es the same pres sure t o both rear brakes, wi th the press ure level bei ng det ermined by t he wheel on thelower fri ct ion s urface. This maint ai ns rear s tabil it y on s pli t fricti on s urfaces .
Corner Brake Control
CBC i nfluences the brake pres sures , below and wit hin ABS thres holds , to counteract the yawing moment produced whenbraking i n a corner. CBC produces a correcti on t orque by li mi ti ng the brake pres sure on one s ide of t he vehicle.
Dynamic Stability Control
DSC us es brakes and powert rain torque control to as s is t i n maint aining the l ateral st abi lit y of t he vehi cl e. W hil e t heignit ion is energi zed t he DSC funct ion i s permanentl y enabl ed, unl es s s elect ed off us ing t he DSC s wit ch. Even i f DSC isdesel ect ed, driving maneuvers wi th ext reme yaw or lat eral accelerat ion may trigger RSC acti vi ty to as s is t t he vehi cl es tabil it y.
DSC enhances dri ving s afet y in abrupt maneuvers and in under-st eer or over-s teer s ituat ions t hat may occur in a bend. TheABS module monit ors t he yaw rat e and l ateral accel erati on of the vehicle, s t eering input , and then s elect ively appli esindivi dual brakes and s ignals for powertrain t orque adjus t ments t o reduce under-s teer or over-s teer.
In general:
In an under-s t eer s i tuati on; the i nner wheels are braked t o count eract the yaw movement t owards t he outer edgeof the bend.In an over-st eer si tuat ion; the out er wheel s are braked to prevent t he rear end of the vehicl e from pus hing t owardst he out er edge of t he bend.
The ABS module monit ors t he tracki ng s tabil it y of the vehicle usi ng inputs from t he wheel s peed s ens ors, t he s teeringangl e s ensor, and the yaw rat e and lat eral accelerat ion sens or. The t racki ng s tabil it y is compared wit h s t ored t arget dat a.W henever t he t racki ng s tabil it y devi ates from t he target dat a, t he ABS modul e int ervenes by appl yi ng the appropriat ebrakes.
The fol lowing interact ions occur i n an i nt erventi on s it uat ion:
High speed CAN s i gnal t o t he ECM, to reduce engine torque.High speed CAN s i gnal t o t he Act ive On-demand Coupl ing module, t o open t he locki ng torque of the centercoupl ing.Applicati on of braking t o t he appropri at e corner of the vehicl e.
Electronic Brake Force Distribution
EBD l imi ts the brake press ure appl ied t o t he rear wheels . W hen t he brakes are appl ied, the wei ght of t he vehicle t rans fersforwards , reduci ng t he abi li ty of t he rear wheels to t rans fer braki ng effort t o t he road s urface. This may caus e t he rearwheels t o s li p and make t he vehi cl e uns table.
EBD us es the ant i-lock braking hardware t o automat icall y opti mize t he pres s ure of t he rear brakes , bel ow t he point whereABS i s normall y i nvoked.
• NOTE: Only the rear brakes are control led by the EBD funct ion.
Electronic Traction Control
ETC att empt s to opt imize forward tract ion by reduci ng engi ne torque, or by applying t he brake of a spi nni ng wheel unt ilt racti on is regai ned.
ETC is act ivated if an i ndi vi dual wheel speed i s above that of the vehicle reference speed (pos i ti ve sl ip) and t he brakepedal i s not pres sed. The brake i s appl ied t o t he s pinning wheel, al lowing t he excess t orque t o be t rans mit t ed to thenon-s pinning wheels through t he dri ve li ne. If neces s ary, the ABS modul e als o s ends a hi gh speed CAN bus mess age t ot he ECM t o reques t a reducti on in engine torque.
W hen t he DSC funct ion i s s elected off us i ng the DSC s wit ch, t he engi ne t orque reducti on feature i s dis abl ed.
Emergency Brake Assist
EBA as si s ts t he driver in emergency braking si tuat ions by automat icall y maximi zi ng the appl ied braki ng effort . There aret wo s it uat ions when t he ABS module wil l invoke EBA:
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W hen t he brake pedal is rapi dly press ed.W hen t he brake pedal is pres s ed hard enough t o bri ng t he front brakes i nto ABS operati on.
W hen t he brake pedal is rapi dly press ed, the ABS modul e i ncreas es t he hydraul ic press ure to al l of the brakes unt il t het hreshol d for ABS operat ion i s reached. This act ion appli es the maxi mum braking effort for the avail abl e t racti on. The ABSmodule moni tors for t he s udden appli cat ion of t he brakes , us i ng inputs from t he brake pedal s wi tch and from the press ures ens or wit hin the HCU. W it h t he brake pedal pres s ed, if t he rat e of increas e of hydraul ic press ure exceeds thepredetermined l imi t, t he ABS modul e invokes emergency braki ng.
W hen t he brake pedal is pres s ed hard enough t o bri ng t he front brakes i nto ABS operati on, t he ABS module increas es thehydraulic press ure to the rear brakes up to the ABS thres hold.
EBA operat ion cont inues unti l the driver rel eas es t he brake pedal , s uffi cientl y for t he hydraulic press ure in the HCU to dropbelow a threshold val ue s tored in t he ABS modul e.
Engine Drag-Torque Control
EDC prevents wheel s li p caus ed by any of t he fol lowing:
A s udden decreas e i n engine t orque when t he accelerator is suddenly released.The s udden engagement of t he clutch after a downs hift on manual t rans mi ss ion vehicl es .A downs hift us i ng the CommandShift functi on on automat ic t rans mi ss ion vehicl es .
W hen t he ABS module det ects t he ons et of wheel s lip wit hout t he brakes being appli ed, t he ABS module s ignal s t he ECMvia t he high speed CAN bus t o reques t a moment ary increase in engine torque.
Hill Descent Control
HDC us es engine braking and brake int ervent ion to control the vehicle speed and accel erati on duri ng low speed off-roaddescents , and in low grip on-road condit ions. General ly, equal pres s ure i s applied to al l 4 brakes , but pres s ure to individualbrakes may be modi fi ed by t he ABS and DSC funct ions to ret ain t he vehi cles s tabil it y. Sel ect ion of t he HDC funct ion i scont rol led by t he HDC s wi tch l ocat ed on t he fl oor consol e. HDC operates at vehicle speeds up t o 50 km/h (31 mph).
W ARNING: Incorrect us e of the HDC functi on may compromis e t he s tabil it y of the vehicle, resul ti ng in a dangerousand uncont roll ed hil l des cent . Pres si ng t he cl utch pedal and/or driving wit h t he trans mi s si on in 'Neutral' whil e HDC i sact ive, wi ll prevent engine braking from ass is t ing t he vehicle. The brakes wil l overheat and i nduce t he HDC fade outs trategy. In this condit ion t here will be no cont rol over t he vehi cl e duri ng a des cent .
• NOTE: W i th the HDC functi on s elect ed, HDC i s operati ve even when the clut ch pedal is pres sed or t he t rans mis s ion i s int he 'Neutral' posi ti on. It is not recommended t o drive t he vehi cl e furt her t han is abs olut el y neces s ary wi th HDC s elected,and t he cl utch pedal press ed/ or the t rans mi ss i on in 'Neut ral '.
On manual transmis s ion vehicles , HDC may be us ed i n firs t and reverse gears only. Once the vehicle is movi ng, t he clut chpedal i s to be ful ly releas ed. The vehicle i s not recommended to be dri ven wit h HDC act ive and t he transmis si on in'Neut ral'.
On aut omati c trans mi s si on vehi cl es, HDC may be us ed i n 'D' dri ve, 'R' revers e and CommandShi ft '1' only. W hen in 'D', t heTCM wi ll automat icall y s el ect t he mos t appropri ate gear. The vehicle is not recommended t o be driven wit h HDC act ive andt he trans mi s si on in 'Neutral'.
HDC i s able t o be sel ect ed at speeds up t o 80 km/h (50 mph), but wi ll only be enabled at s peeds bel ow 50 km/h (31 mph).
W hen HDC is s elect ed:
At s peeds up t o 50 km/h (31 mph), the HDC informat ion i ndi cat or lamp i s permanentl y i llumi nated i f a valid gear i ss elect ed.At s peeds bet ween 50 to 80 km/h (31 to 50 mph), t he HDC i nformat ion indicator lamp fl ashes and on vehicles wit ht he high l ine i ns t rument clus ter, a mes s age advis i ng that t he s peed i s t oo high i s dis played in the mes s age cent er.If the HDC swit ch is pres s ed whil e t he vehi cl e s peed is great er than 80 km/h (50 mph), the HDC informat ionindicat or l amp wi ll not il lumi nat e and HDC will not be s elected.If the s peed reaches 80 km/h (50 mph) or more, a warni ng chi me i s s ounded, the HDC functi on is swi tched off, t heinformat ion i ndi cat or lamp is exti ngui shed and, on vehicles wi th the hi gh li ne ins trument cl ust er, a mess ageadvi s ing t hat HDC has been swi tched off i s dis played i n the mess age center.
For addit ional informat ion, refer t o:
Ins trument Clus ter (413-01 Ins t rument Clus t er, Descripti on and Operat ion),Informat ion and Mes s age Cent er (413-08 Informati on and Mes sage Cent er, Descripti on and Operat ion).
W hen HDC is enabled, the ABS module calculat es a t arget speed and compares t his wi th the act ual vehicle s peed. The ABSmodule t hen operates the HCU in t he acti ve braking mode as required, t o achi eve and maint ain t he t arget speed.Operat ion of t he vehi cl e s toplamps during HDC is controll ed by the CJB.
Applying t he foot brake during acti ve braking may res ult i n a puls e being felt t hrough t he brake pedal.
The t arget speed vari es bet ween mi nimum and maximum values for each gear and t rans miss ion range, dependi ng on driverinputs through t he foot pedals . If the foot pedals are not operated, t he ABS module adopts a default t arget s peed:
HDC Target Speeds
T arget Speed
Automatic T ransmission GearManual T ransmission Gear
1st and DriveReverse1stReverseDefaul t10 km/h (6 mph)3.5 km/h (2.2 mph)10 km/h (6 mph)8 km/h (5 mph)
Mi ni mum6 km/h (3.7 mph)3.5 km/h (2.2 mph)7.5 km/h (4.7 mph)8 km/h (5 mph)
Maximum20 km/h (12.4 mph)3.5 km/h (2.2 mph)20 km/h (12.4 mph)8 km/h (5 mph)The t arget speed i s varied bet ween the mini mum and maxi mum values us ing the accel erator pedal, or by pres s ing t he