
1
2
Publi s hed: 11-May-2011
Anti-Lock Control - Anti-Lock Control
Diagnosi s and Tes ti ng
Principles of Operation
For a detail ed descripti on of the Ant i-lock Braking Sys t em (ABS), refer to the relevant Des cri pt ion and Operati on s ect ion i nt he works hop manual . REFER t o: Anti -Lock Cont rol - St abi li ty As s is t (206-09C Anti -Lock Cont rol - St abi lit y As s is t,Des cript ion and Operat ion).
Inspection and Verification
CAUTION: Di agnos is by s ubs ti tut ion from a donor vehicle is NO T acceptabl e. Subs ti tut ion of cont rol modules doesnot guarant ee confirmat ion of a faul t, and may als o caus e addit ional fault s i n t he vehi cl e being t est ed and/or t he donorvehi cl e.
• NOTE: Pri or to any t es ti ng or ins pect ion, the vehicle should be check for any relevant warning l amps bei ng il lumi nat ed. Ifa warning l amp is ill uminat ed, check for DTCs and refer to t he relevant DTC Index, if no warni ng lamp is i ll uminated,cont inue wi th diagnos t ic procedures below.
1. Verify t he cus t omer concern.1.
2. Vis ually ins pect for obvious s igns of damage and s ys t em i ntegri ty.
Visual InspectionMechanicalElectrical
Brake flui d levelVacuum s ys t emW heel s peed sens or ins tall ati onW heel s peed sens or ai r gapSt eering wheel rot ati on sens orAccel erometer/s ens or clus t er i nst all ati onIncorrect wheel or t ire s ize
W arning light operat ionFus esW heel s peed s ens orsConnect ors /Pi nsHarnes s esSt eering wheel rot ati on s ens orAccel eromet er/sens or cl ust erHydraul ic Control Uni t (HCU)
2.
3. If an obvious cause for an obs erved or report ed concern is found, correct t he caus e (if pos s ible) beforeproceeding t o t he next s t ep3.
4. If t he caus e is not vis ually evi dent , check t he ant i-lock braking sys tem and s teering rot ati on s ens or modules forDi agnos ti c Trouble Codes (DTCs) and refer t o t he rel evant DTC Index.4.
DTC Index
• NOTE: If the control modul e or a component i s s us pect and the vehicle remains under manufacturer warrant y, refer t o theW arranty Pol icy and Procedures manual (s ect ion B1.2), or determine i f any pri or approval programme is in operat ion, pri ort o the ins tall ati on of a new module/component.
• NOTE: Generic scan t ool s may not read the codes li st ed, or may read only fi ve digit codes . Mat ch the five di git s from t hes can tool to the firs t fi ve di git s of the seven digi t code l is ted to ident ify t he faul t (t he las t t wo digi ts gi ve addi ti onalinformat ion read by the manufact urer approved diagnos t ic s ys tem).
• NOTE: W hen performing volt age or res is t ance t est s , always use a digi tal mult imeter (DMM) accurat e t o t hree deci malplaces, and wi th an up-t o-date cal ibrat ion cert ificate. W hen tes ti ng res is t ance al ways take t he res is t ance of t he DMMleads i nt o account .
• NOTE: Check and recti fy bas ic faul ts before beginni ng diagnos t ic rout ines i nvol vi ng pinpoint t es t s.
• NOTE: Ins pect connect ors for s igns of water ingres s , and pins for damage and/or corros ion.
• NOTE: If DTCs are recorded and, aft er performi ng the pi npoi nt tes ts , a fault is not present , an int ermi tt ent concern maybe t he caus e. Always check for loose connect ions and corroded terminals .
For a compl ete lis t of all Di agnos ti c Trouble Codes (DTCs) t hat could be logged on this vehicle, pleas e refer to Sect ion100-00.REFER t o: Di agnos t ic Trouble Code (DTC) Index - DTC: Ant i-Lock Braki ng Sys t em (ABS) (100-00 GeneralInformat ion, Des cript ion and Operat ion).
Pinpoint Tests
PINPOINT TEST A : BRAKE VACUU M ASSIST FU NCTION
T ESTCONDIT IONSDET AILS/RESULT S/ACT IO NS
A1: CHECK T HE BRAKE PEDAL T R AVEL WIT H T HE ENGINE OFF
Set i gnit ion s wit ch t o OFF.
Pump t he brake pedal s ix ti mes and hold firm press ure on t he pedal .
Did t he pedal t ravel decreas e and t he pedal go hard as i t was pumped?YesGO t o A2.NoCHECK the vacuum circui t to the brake boos t er. Start the engine and idle for three mi nut es, s wi tchignit ion OFF t hen repeat t he tes t. If t he pedal t ravel does not decreas e, s uspect the brake boos t er.
A2: CHECK T HE BRAKE PEDAL T R AVEL WIT H T HE ENGINE RUNNING

3-Right -Hand (RH) rear wheel s peed s ens or
4-Steering wheel modul e (including s t eering angle sens or)
5-Left -Hand (LH) rear wheel s peed s ens or6-Sensor clus ter
7-LH front wheel speed s ensor
8-Int egrat ed Anti -l ock Brake Sys t em (ABS) modul e and Hydrauli c Cont rol Unit (HCU)9-RH front wheel speed s ensor
10-Central Junct ion Box (CJB)
OVERVIEW
The vehi cl e ABS and s t abi li ty control sys tem feat ures a Cont inental Teves Mk25E1 module, wi th an int egral 4-channel HCU.The int egrated ABS modul e and HCU is l ocat ed on t he rear LH s ide of t he engine compart ment, and i s ins tal led i n t hebrake hydrauli c ci rcuit bet ween the brake mas ter cyl inder and the 4 brake calipers.
The ABS module is connect ed to the hi gh s peed Cont roll er Area Net work (CAN) bus , and acti vel y int eracts wi th othervehi cl e s yst em cont rol modules and as sociat ed s ens ors to recei ve and transmit current vehicle operat ing informati on.
W hen requi red, t he ABS module wi ll acti vel y int ervene and operate the HCU during braki ng or vehi cl e maneuvers t o correctt he vehi cl e att it ude, s t abi li ty, t racti on or speed. During severe incident s of vehicle correct ion, t he ABS module will al soreques t the Engine Cont rol Modul e (ECM) to reduce engi ne power i n order t o further stabil ize and correct t he vehicle.
To provide full s ys tem functi onali ty, t he ABS and DSC s ys tems compris e t he fol lowing component s :
DSC s wit chHDC s wi tch4 wheel s peed s ens orsSens or clus terSteering angle s ens orIns t rument clus ter i ndi cat or lampsInt egrat ed ABS module and HCU.
The ABS s yst em al s o provides brake funct ions t hat are des igned to ass is t t he vehi cle or aid the driver. The followi ngfuncti ons are det ai led i n t he s ect ion 'Principl es of Operati on':
Anti -l ock Brake Sys t em (ABS)Corner Brake Control (CBC)Dynamic St abi li ty Cont rol (DSC)Electroni c Brake Force Di s tributi on (EBD)Electroni c Tracti on Control (ETC)Emergency Brake As s is t (EBA)Engi ne Drag-Torque Control (EDC)HDC (wit h gradi ent releas e cont rol )Roll Stabi lit y Control (RSC)Terrai n Res pons e™ sys tem int egrati on.
All t he brake funct ions li s ted, apart from HDC, are automat icall y act ive when t he i gni ti on is in power mode 6 (igni ti on) andt he engi ne is runni ng.
DYNAMIC STABILITY CONTROL SWITCH
The DSC s wit ch all ows the DSC functi on to be s elect ed off. The DSC s wi tch i s non-latchi ng and is i nst all ed in the floorcons ole, forward of the gear s el ect or lever. Pres s ing t he DSC s wi tch connects an ignit ion power feed to t he ABS modul e.W i th the firs t pres s of the DSC swit ch, t he ABS module di sabl es the DSC funct ions . When t he DSC s wi tch i s pres sed agai n,t he ABS module re-enables t he DSC funct ions. The DSC swi tch must be press ed for a minimum of 0.3 s econd for the ABSmodule t o react . The DSC functi on is re-enabled at t he beginning of each ignit ion cycle.
To confirm that t he DSC functi on is sel ect ed off, the amber colored DSC warni ng indicator l amp located i n t he ins t rumentclus ter, is conti nuous ly i ll uminated. On vehicles i nst all ed wit h a hi gh-li ne ins t rument clus ter, a mes sage i s als o di spl ayedin the mess age cent er to confirm t hat DSC is s elect ed off.
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 t he DSC funct ion i s s elected on, t he DSC warni ng indicator l amp is ext inguis hed.
Alt hough Land Rover recommend t hat DSC is s elected on for all normal driving condit ions, i t may be benefi ci al t o de-sel ectDSC i n order t o maximi ze tract ion under t he foll owing condit ions:
To rock t he vehicle out of a holl ow or a s oft surface.W hen driving on loose s urfaces or wit h s now chains ins t al led.W hen driving i n deep s and, s now or mud.W hen driving on tracks wi th deep l ongi tudinal rut s .
Even when DSC is des elected, dri ving maneuvers wi th ext reme yaw or lateral acceleration may trigger RSC act ivit y t oas si st the vehicle st abili ty.
To prevent mis -use of, or in the event of a broken DSC s wit ch, a Diagnost ic Troubl e Code (DTC) i s s tored in the ABSmodule memory i f the input from t he DSC s wit ch is hel d high for more than 1 minut e.
HILL DESCENT CONTROL SWITCH
The HDC s wi tch control s t he s el ect ion of t he HDC funct ion.

The HDC s wi tch i s non-lat chi ng and is ins tall ed in the floor cons ole, forward of the gear s el ect or lever. Moment aril ypres s ing and releasi ng t he HDC s wit ch connects an ignit ion power feed t o t he ABS module. W it h t he fi rs t pres s and rel easeof the HDC s wit ch, t he ABS module enables operat ion of t he HDC funct ion. W hen t he HDC swi tch i s pres s ed and rel eas edagai n, the ABS modul e dis ables operat ion of t he HDC funct ion.
To prevent mis -use of, or in the event of a broken HDC s wi tch, if t he s wit ch is press ed for more t han 10 s econds nochange of s tat e occurs. A DTC i s s tored in t he ABS module memory if t he input from the HDC swi tch i s held hi gh for moret han 1 mi nut e.
HDC Activating Stoplamps
Operat ion of t he vehi cl e s toplamps during HDC is controll ed by the CJB. The ABS module monit ors t he brake s yst emhydraulic press ure and request s t he CJB, vi a t he high s peed CAN bus, t o energi ze the s t opl amps duri ng act ive braki ng.
A press ure thres hold and ti me fil ter prevents t he s topl amps from fli ckeri ng whil e HDC i s braking.
Stop/St art Vehicl es - From 2010 MY
Acti vat ion of Hi ll Descent Cont rol wi ll deact ivate the St op/St art s yst em. However, if Hi ll Des cent Control i s acti vat ed whent he engi ne is s hutdown in a St op/St art cycl e t he engi ne wil l aut omati cal ly rest art . If during t his event the St op/St arts ys t em cannot det ect t he dri ver's occupancy, for exampl e eit her t he driver’s safety belt or door is unl at ched, t he engi newil l not res tart. The St op/Start sys tem wi ll request the driver to depres s t he clut ch to res tart the engine. The dri ver wi ll beinformed of t his by ‘RESTART REQUIRED PRESS CLUTCH’ being di spl ayed i n t he mes sage center.
The dri ver mus t respond t o t hi s reques t wit hin a li mit ed t ime period, or otherwi s e a convent ional engine res tart us i ng theignit ion swi tch will be requi red.For addit ional informat ion, refer t o: Starti ng Sys t em (303-06C Starti ng Syst em - TD4 2.2L Di es el, Vehicles Bui lt From:01-03-2009, Descripti on and Operat ion).
WHEEL SPEED SENSORS

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:

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

s peed control '+' and '-' but t ons (dependant on vehi cl e s peci fi cat ion). The HDC Target speed wi ll als o vary depending ont he Terrai n Respons e™ mode sel ect ed.
Duri ng changes of target s peed, the ABS modul e li mit s vehicle decelerat ion and accelerat ion t o -0.5 met ers per s econd
s quared (m/s2) (-1.64 feet per s econd squared (ft/s2)); and +0.5 m/s2 (+1.64 ft/s2) res pect ively.
To provide a s afe t rans it ion from acti ve braking t o brakes off, the ABS module i nvokes a fade out st rat egy that graduall yrel eas es t he braking effort during act ive braking. The fade out s t rat egy occurs i f any of t he fol lowi ng condit ions i s detectedduri ng act ive braki ng:
HDC i s s elected off us i ng the HDC s wit ch.Failure of a component us ed by HDC, but not crit ical t o fade out funct ion.Accelerator pedal pres s ed when t rans mis s ion i s i n neut ral .Brakes overheat .
If fade out is i nvoked becaus e of HDC de-s el ect ion or component failure, the HDC functi on is cancel led by t he ABS module.If fade out is i nvoked becaus e t he accelerator pedal i s pres s ed wit h t he t ransmis s ion i n neut ral , or because of brakeoverheat , t he HDC funct ion remains in s tandby and res umes operati on when t he accelerat or pedal is releas ed or the brakeshave cooled.
The fade out s t rategy i ncreas es t he t arget speed at a cons tant accelerati on rat e of 0.5 m/s2 (1.64 ft/s2), unti l themaximum t arget speed i s reached, or unti l no act ive braki ng is required for 0.5 second. If t he accelerat or pedal is
posi ti oned wit hin t he range t hat infl uences t arget s peed, the accelerat ion rate is increas ed t o 1.0 m/s2 (3.3 ft /s2).
W hen fade out is i nvoked becaus e of component fai lure, a warning chime is sounded and the HDC informat ion i ndi cat orlamp is ext inguis hed. The HDC warning i ndicat or lamp is t hen il lumi nat ed (on low-li ne ins trument cl ust er), or a mes s ageadvi s ing of t he fault i s dis played in the mess age cent er (on hi gh-l ine i ns t rument clus ter).
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 fade out is i nvoked becaus e of brake overheat, on vehicles wi th the hi gh-li ne ins t rument clus ter, a mes sage advis ingt hat HDC is t emporarily unavail abl e is di s pl ayed. On vehicles wit h t he low-line ins trument cl us t er, t he HDC warningindicat or l amp flas hes . At t he end of fade out, t he HDC informati on indicat or flas hes. The flas hing warni ng and informat ionindicat or l amps, and/or di spl ayed mes s age cont inue whi le HDC remai ns sel ect ed, unt il t he brakes have cooled.
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).
To monit or for brake overheat, t he ABS modul e monit ors t he amount of braking acti vi ty and, from thi s, es ti mat es thet emperature of each brake. If the es t imat ed temperature of any brake exceeds a pres et li mit , t he ABS module i nvokes t hefade out s t rategy. Aft er the fade out cycle, t he HDC funct ion i s re-enabl ed when the ABS modul e es ti mates that all of thebrake t emperatures are at l ess than 64% of the preset t emperat ure l imi t.
Roll Stability Control
The RSC funct ion us es the brakes and the engine t o at tempt t o rest ore vehicle s tabilit y, i f the vehicle is forced i nt o ahars h maneuver t hat ri sks i t ti pping over.
The ABS module monit ors dri ver i nput s and vehicle behavior usi ng various powert rai n s ignals and t he i nput s from thewheel s peed s ens ors, t he s teering angle s ens or, the roll rate sens or, yaw rate and lateral accel erat ion s ensors. Thes einputs are compared wit h modeled behavi or and, if t he vehicle behavior reaches a given ris k level, t he ABS module cut st he engi ne power, or brakes one or more wheels suffi ci ent ly to al low the vehicle to regain s t abi li ty and hel p the driverremai n i n cont rol .
W hi le t he i gni ti on is energi zed, RSC i s permanentl y enabl ed even if t he DSC functi on is sel ect ed off.
Terrain Response™ System Integration
The Terrai n Res pons e™ funct ion integrat es t he ABS and other vehicle s ys tem cont rol modules t o as si s t the vehicle whendri vi ng off-road or during di fficult s urface condit ions . Terrai n Respons e is act ivated when the rotary cont rol s wit ch is s et t oa Terrain Res ponse special program.
W hen a Terrai n Respons e s peci al program i s acti vat ed, t he ABS module along wi th ot her vehicle s ys t em control modul eswil l operate in accordance wi th programmed software maps . The s oftware maps al low t he ABS s ys tem to functi on wit h at hreshol d that wi ll as si s t the s elected Terrai n Respons e s pecial program.For addit ional informat ion, refer t o: Ride and Handli ng Opti mizat ion (204-06 Ride and Handli ng Opt imi zat ion, Descripti onand Operat ion).

Publi s hed: 11-May-2011
Steering System - General Information - Steering System
Diagnosi s and Tes ti ng
Principle of Operation
For a detail ed descripti on of the st eering sys tem, refer t o t he rel evant Des cript ion and Operat ion s ecti on in the works hopmanual. REFER to:
Steeri ng Sys t em (211-00 St eering Sys tem - General Informat ion, Diagnos i s and Test ing),Power St eering (211-02 Power Steeri ng, Des cri pti on and Operati on),Steeri ng Linkage (211-03 St eering Li nkage, Descripti on and Operat ion),Steeri ng Column (211-04 St eering Col umn, Des cri pti on and Operati on).
Inspection and Verification
1. Verify t he cus t omer concern by operat ing t he s yst em.1.
2. Vis ually ins pect for obvious s igns of damage and s ys t em i ntegri ty.2.
Visual Inspection
MechanicalCheck the t ires for correct press ure, s ize and t read pat ternCheck for wheel rim and t ire damageCheck road wheel securi tyCheck the power s teeri ng fluid level and t he hydraulic ci rcuit for flui d leaksCheck the power s teeri ng pump drive belt condi ti on and t ens ionCheck the power s teeri ng pump for securi ty, wear, damage and exces s ive nois eCheck the s t eering gear as sembl y for damage, wear and s ecurit yCheck the hydrauli c pipes and cool er li nes for damage and correct rout ingCheck the s t eering joint s for damage, excess i ve play, wear and s ecurit yCheck the s t eering column and joi nt s for damage, exces s ive play, wear and securi ty
3. If an obvious cause for an obs erved or report ed concern is found, correct t he caus e (if pos s ible) beforeproceeding t o t he next s t ep.3.
4. If t he concern is not vis uall y evi dent , verify t he s ymptom and refer t o t he Symptom Chart .4.
Symptom Chart
• NOTE: If a component is sus pect and t he vehicle remains under the manufact urer warrant y, refer t o t he W arrant y Policyand Procedures manual (s ect ion B1.2), or determine i f any prior approval programme is i n operat ion, prior t o t heins t al lat ion of a new component.
SymptomPossible CauseAction
St eering wandersExces s ive free pl ay in t hes teering s yst emSt eering geometryi ncorrect ly al igned
Check for excess i ve movement or play i n t he s teeri ng s yst em wit hthe engine running. Check for pl ay at several different s t eeringpos i ti ons . Carry out st eeri ng geomet ry and alignment checks .REFER t o: Four-W heel Al ignment (204-00 Sus pens i on Sys t em -General Informati on, General Procedures ).St eering pull s t o t hel eft or ri ghtSt eering/s us pens ioncomponent s damaged,bent, l oos eSt eering geometryi ncorrect ly al igned
Check s t eering and s us pens ion component s for damage/correctins tal lati on. Carry out s t eering geometry and ali gnment checks .REFER t o: Four-W heel Al ignment (204-00 Sus pens i on Sys t em -General Informati on, General Procedures ).
St eering feel snotchy when t urningfrom lock to lock
St eering or s uspens ions wivel joi nt s s eizedSt eering t ie rod end jointsor t rack rod i nner joint ss eizedSt eering column orunivers al joi nt s s eizedSt eering gear int ernalcomponent s mi sal igned,worn or damaged
Dis connect the s t eering gear from the s us pens ion. Check forfreedom of movement i n t he s us pensi on. Di s connect t he s teeringcol umn from the s t eering gear. Check t he st eeri ng col umn anduni vers al joint s for freedom of movement. Check the s t eeringgear for freedom of movement . Rect ify as neces s ary.
St eering feel s t ightand does nots elf-center
Power st eeri nghydrauli cs noi syoperat ion
Power st eeri ng fl uid l evell ow or cont aminatedPower st eeri ng fl uidaerat edPower st eeri ng hos est wis t ed or res tricted
Check and t op-up t he power st eering fl ui d l evel if requi red.REFER t o: Power St eeri ng Sys t em Bl eeding (211-00 St eeringSys t em - General Informat ion, General Procedures ).Check for contaminated flui d. Check for air i ngres s int o t hesys t em. Check t he power s t eering hos es for t wis t ing orres trict ions. Recti fy as neces sary.
Power st eeri ng pumpnois yPower st eeri ng fl uid l evell ow or cont aminatedPump i nternal component sworn or damaged
Check and t op-up t he power st eering fl ui d l evel if requi red.REFER t o: Power St eeri ng Sys t em Bl eeding (211-00 St eeringSys t em - General Informat ion, General Procedures ).Check for contaminated flui d. Check for exces s ive pump noi se.Ins tal l a new pump as required. Refer t o t he new componentins tal lati on note at t he t op of the Sympt om Chart

Publi s hed: 11-May-2011
Steering System - General Information - Power Steering System Bleeding
General Procedures
Clean power s teering fluid res ervoir around t he fi ll er cap and flui di ndi cat or.1.
Check the power s teeri ng fluid, if aerat ed, wait unti l fl ui d i s freefrom bubbles then t op-up res ervoi r to UPPER l evel mark wit hrecommended fluid.
2.
3. CAUTION: Flui d mus t always be pres ent in theres ervoi r during bl eeding.
Remove t he fi ll er cap and fil l t o t he MAX level mark.
3.
Inst all t he fi ll er cap.4.
St art t he engi ne and allow to run for 10 s econds, s t op t he engi ne.5.
Check the power s teeri ng fluid, if aerat ed, wait unti l fl ui d i s freefrom bubbles then t op-up res ervoi r to UPPER l evel mark wit hrecommended fluid.
6.
St art t he engi ne and turn s teering ful ly lock to lock, s t op the engine.7.
Check and top-up power s t eering fluid level.8.
St art and run the engine for 2 mi nut es , turn the st eeri ng full y l ock t ol ock.9.
Check and top-up power s t eering fluid level.10.