2006 LAND ROVER FRELANDER 2 ECO mode

Each sub-sys tem operates in di fferent ways in relati on t o t he sel ect ed Terrai n Res pons e program t o achieve t he opt imumt racti on, s t abi lit y and eas e of cont rol for t he t errai n encount ered.
Engine Management System (EMS)
The EMS can change t he accel erator pedal maps to change the amount of t orque per percent age of pedal travel .
Each terrain program uses a combi nat ion of operat ing paramet ers for each sub-sys tem. Changing bet ween terrain programsini ti at es a di fferent s et of operat ing characteris ti cs which wil l be noti ceable to the driver, for example; i f the accel erat orpedal i s held i n a const ant pos i ti on and the terrain program is changed from Gras s /Gravel /Snow t o Sand, the driver wil lnoti ce the t orque and engine s peed increas e. If t he t errai n program is changed from Sand t o Grass /Gravel/Snow, t he dri verwil l not ice a reduct ion in t orque and engine s peed.
• NOTE: The change i n t orque and engine s peed can take approximat ely 30 s econds and care mus t be taken not to confus et he Terrai n Respons e s yst em operat ion wit h an EMS faul t.
Transmission Control (Automatic transmission only)
The t ransmis s ion control modul e changes t he shi ft maps for the Terrain Respons e program s elect ed. Thi s changes t he s hi ftpoints providing early or l at e ups hift s and downs hi ft s .
For example, i n t he Gras s /Gravel /Snow program, the trans mi ss i on wil l perform early ups hi ft s and very late downs hifts toensure t he transmis si on is in t he highes t gear pos si ble. The hil l det ect ion funct ion of t he Trans mis s ion Cont rol module(TCM) will l ock t he t orque converter and hold whi chever gear i s s el ect ed t o t he engine s peed (RPM) li mit i f neces s ary whendescending a s t eep incli ne. This provi des maximum engi ne braking before t he dri ver needs t o appl y t he brakes.
Sport mode i s only avail abl e when t he general program i s s elected. Sport mode i s disabled i n all Terrain Res pons e s peci alprograms. 'CommandShift ™' is avail abl e in any program.
Active On-Demand Coup ling Control
The act ive on-demand coupli ng cont rol module has 2 operati ng s trat egies ; pre-empt ive and react ive.
The pre-empti ve st rat egy anti ci pat es and predict s the locki ng torque val ue required t o mi ni mi ze sl ip and maxi mizes tabil it y. Each Terrain Res pons e program has a different t hres hol d and i nput cri teria for the pre-empt ive s t rategy. Forexampl e, a higher locki ng t orque would be appl ied on s li ppery s urfaces .
The reacti ve s trategy vari es the amount of locking t orque in res pons e t o t he actual s lip level and t he dynamic behavi or oft he vehi cl e. Each Terrain Res pons e program has a different t hres hol d and input for the react ive s trategy. The reacti ves trategy i mproves vehi cl e t racti on and compos ure by eliminati ng any wheel s pin which has occurred aft er the pre-empt ives trategy was appli ed. The l ocking res pons e appli ed is appli cable to the t errain program sel ect ed. For exampl e, verys ens i ti ve on s lippery surfaces to provide maximum t racti on and mi nimi ze surface damage.
The locking t orque calculati ons use various s ignals from other s ub-s yst ems , for example, engi ne torque, accel erator pedalposi ti on, s elect ed gear, st eeri ng angl e, vehicle s peed, lat eral accelerat ion, yaw behavi or.
The DSC funct ion of t he ABS s ys t em can override t he act ive on-demand coupli ng cont rol and reduce any appl ied l ocki ngt orque during DSC act ion.
ABS System Control
The ABS module cont rols several functi ons and adjust s t he operati ng paramet ers of t hes e funct ions t o opti mize thes elect ed Terrain Res pons e program.
Tracti on Control
Tracti on cont rol us es different s li p/accel erati on thresholds to i mprove t ract ion and vehicle compos ure. For example, t hes ys t em s ens it ivit y is increased on s lippery surfaces s uch as wet grass or s now t o reduce wheel s pi n. If wheel s pi n wasall owed in t hese ci rcums tances, l oss of t ract ion may res ul t from surface damage (wet grass ) or t he car being unable tomove (snow) due t o wheel spi n.
Dynamic St abi li ty Cont rol
If DSC is s wi tched off (wit h t he DSC s wi tch adjacent to t he Terrain Res pons e rotary cont rol ) when usi ng a TerrainRespons e s peci al program, if t he s peci al program i s s ubs equent ly changed for a di fferent program, DSC is aut omat icall ys wit ched back on.
The DSC us es different t hres hol d values for t he s elected program t o aut omati call y reduce DSC i ntervent ion, removing t herequirement for t he dri ver t o dis able t he DSC s ys tem in order to reduce engine intervent ion whi ch is s omet imes i nduced i nextreme off-road condi ti ons . In ext reme s and condit ions , there may be an addit ional benefit of dis abling the DSC funct ionus ing t he DSC s wit ch in addi ti on to sel ect ing t he s and program.
In the Mud/Ruts program the DSC sys tem is cal ibrat ed t o tol erate a higher 'yaw' thres hold. This al lows a greaterdifferent ial between t he actual and des i red wheel turni ng behavi or before DSC i ntervenes . Thi s all ows the DSC s ys t em t oignore the effect of rut s 'jarring' t he car or adjust ing t he front wheel s t eering angle.
The Terrai n Res pons e s ys tem can al ter t he balance bet ween engine and brake i ntervention. For example, when t he s andprogram is sel ect ed, t he DSC s ys tem reduces it s rel iance on engi ne int erventi on and increas es the us e of brakeint erventi on to maint ai n t he vehi cl es momentum and prevent it from becomi ng bogged down i f wheel s li p i s detected.
Hil l Descent Cont rol
HDC i s automat icall y s wit ched on or off and target s peeds are adjus t ed in res pons e to t he Terrai n Res pons e programs elect ed. The res pons iveness of the HDC functi on is al so increas ed where requi red.
Automat ic operat ion of HDC ai ms t o as s is t the driver by s wit chi ng t he sys t em on or off when it is of most benefi t. HDC isonly aut omat icall y s wit ched on when the mud/rut s program i s s elect ed. HDC i s not automati cal ly s elected in ot her

programs.
Incorrect Program Usage
Selecti on of an inappropri at e program i s dis couraged in t he followi ng ways:
The act ive program icon is conti nual ly di spl ayed i n t he ins t rument clus ter mes s age centerThe Terrai n Res pons e control modul e 'l ocks ' out cert ain funct ions i n s ome programs, for exampl e:- cruis e control is only avai lable wi th the special programs off or gras s/gravel/s now program- t rans mis s ion 'Sport' mode i s deact ivated i n all s peci al programs .W hen t he i gni ti on has been in t he off mode, cont inuall y for more t han 6 hours , t he Terrai n Respons e s yst emdefault s t o t he special programs off.
Selecti on of an inappropri at e program for the t errain condit ions wil l not endanger the dri ver or cause damage to thevehi cl e. Cont inued us e of an inappropri ate program may reduce t he li fe of s ome component s . The driver may not icereduced vehi cl e res ponse, wi th the engine and t rans mi ss i on bei ng les s respons ive t han in s peci al programs off. Al so, i ns ome programs, HDC wil l remai n on, si gni fi ed by il lumi nat ion of t he HDC indicator in the i nst rument clus t er. The dri ver mayals o not ice t orque 'wi nd-up' i n t he act ive on-demand coupli ng caus ing a braking effect when the vehicl e is manoeuvred i ns ome s peci al programs .
Driver Information
The high-l ine i nst rument clus t er fit t ed to al l vehi cl es wit h Terrain Res pons e, cont ains a mess age center which di spl aysvehi cl e i nformat ion to t he driver. The mes s age cent er contai ns the Terrain Res ponse program icons which dis play t hecurrent ly s elected program. If no s ymbol i s dis played, no special program is sel ect ed and the sys tem is in 'Specialprograms off'.
Any required changes t o t he s ub-s ys t ems are al s o pass ed t o t he dri ver i n t he form of i ndi cat or ill uminat ion i n t heins t rument clus ter or appropriat e mes s ages i n t he mes s age center, 'HDC OFF' for example.
In certai n operati ng condi ti ons , t he Terrai n Res pons e s yst em al s o dis plays advi ce or warning mess ages to ens ure thedri ver i s us ing t he vehi cl e t o it s full potenti al, for example, s t eering angle is dis played i n t he mes sage center t o avoi ddri vi ng in deep rut s wit h s t eering l ock appli ed.
DIAGNOSTICS
The Terrai n Res pons e control modul e s tores informati on on detect ed Terrai n Respons e faul ts and CAN errors whi ch can beint errogat ed usi ng IDS. The Terrain Res ponse s ub-s ys t ems and t he ins trument cl ust er als o s tore informat ion relat ing t oCAN errors from t he Terrain Res pons e control modul e.
The cont rol module al s o s tores the mil es travel ed and ti me el aps ed for t he i ndi vi dual programs which can al so be ret ri evedus ing IDS. Thi s informat ion aids di agnos is of t he Terrain Res pons e s ys tem and als o provi des an indicati on of Terrai nRespons e s yst em abus e by t he dri ver whi ch can l ead to premat ure component failure.
This i nformat ion can al so be us ed to check cus t omer concerns , for exampl e, hi gh fuel cons umpt ion whi ch may be due t ocont inued us e of a cert ain program.
Terrain Response System Fault Diag nosis
Terrai n Res pons e relies on the correct funct ionali ty of t he 4 s ub-s ys tems . If one of the s ub-s ys tems develops a fault , theTerrai n Res pons e s ys tem wil l not funct ion, even though the fault i s NOT in t he Terrain Res pons e s ys tem.
T he T errain Response control module and rotary control should only be investigated if there are no apparent faultsin any of the sub-systems. If a fault in a sub-system is subsequently corrected, the T errain Response system willfunction normally after an ignition mode 1 and 2 (on and off) cycle.
Terrain Response Sub-System Faults
W hen a fault occurs i n a s ub-s yst em, t he dri ver i s alert ed by t he il lumi nat ion of a warning indicator and/or an appropri atemes s age for that s ub-s yst em in t he i ns t rument clus ter mes s age cent er. There wi ll be no warning of a Terrain Res ponses ys t em fault .
W hen a sub-sys t em faul t is present and t he dri ver at tempt s t o s el ect a different Terrain Res pons e program us i ng therot ary control or at t he next ignit ion mode 2 (on) cycl e, a mes sage 'SY STEM FAULT SPECIAL PROGRAMS NOT AVAILABLE'wil l appear in the mess age cent er. This impl ies t hat t he Terrain Res pons e s ys tem has a faul t, but only because asub-system fault is preventing its operation. Thi s mes sage will be di spl ayed for 5 s econds per ignit ion mode 2 cycl e, butis repeat ed i f a further s electi on is made by the driver usi ng t he Terrai n Respons e rot ary control or at t he next ignit ionmode 2 (on) cycle.
• NOTE: The mes s age 'SY STEM FAULT SPECIAL PRO GRAMS NOT AVAILABLE' can al so be generated by a fault i n t he Terrai nRespons e rot ary control or control modul e. Refer to the foll owing i nformat ion for det ail s of rot ary control or control modul efaul ts .
It is not possible for the T errain R esponse control module to cause any fault behavior (w arning indicator illuminationor message generation) in any of the 4 sub-systems. Illuminati on of a s ub-s ys t em warning i ndi cat or and/or as ub-s ys t em relat ed mes sage wi ll NEVER be ass ociated wit h a Terrain Res ponse cont rol module or Terrain Res pons es ys t em fault .
The s ub-s ys t em control modul es can det ect a fault wit h the CAN s ignal from t he Terrai n Res pons e control modul e. If afaul t in t he Terrain Res pons e s ys tem is det ect ed, the s ub-s ys tem cont rol modules wi ll operate in t he 'Special programs off's ett ing. The s ub-s ys t em control modul es wil l record a fault code for a fail ure of t he Terrai n Res pons e CAN si gnal . Thes efaul ts can be retrieved us ing IDS and wi ll provide us eful informat ion t o i ndi cat e i nves ti gat ion of t he Terrain Res pons econt rol module or t he CAN net work.
Terrain Response Rotary Control or Control Module Fault

Not s ens it ive to brake tes ti ng on a chas si s dynamomet er.
Generati on 4 Acti ve On-Demand Coupli ng - Vehicles from 2009MY
The generati on 4 coupl ing does not have the di fferenti al s peed dri ven pump used on the previ ous generat ion 3coupl ing, but i s fit ted wi th a bigger capacit y electrically operated axial pump and a hi gh pres s ure accumul ator.The proport ional throt t le valve and press ure s ens or on t he generat ion 3 coupli ng is replaced wit h a proport ionalpres s ure reducing val ve.The t orque li mit er pres sure reducing valve on the generat ion 3 coupli ng is replaced by an electroni c cont rol valveand cont rol ling software.
The generati on 4 acti ve on-demand coupli ng gives t he fol lowing improvements over t he previous generati on 3 coupl ing:
Reduced bas e t orque at high different ial s peedsTorque acti vat ion i s now i ndependent of different ial s peedAccurat e t orque l imi ter cont rolEnergy s tored in hi gh pres s ure accumul ator givi ng a low maximum current consumpt ion of t he electric pump andfas t er res pons e.
Control Module - G eneration 3 and 4 Couplings
The cont rol module, at tached to the cas ing of t he act ive on-demand coupling, forms a s ingle unit wit h t he cont rolvalve/axial s ol enoi d. By anal yzi ng informat ion from other vehi cl e modules and s ensors t he cont rol module regul ates t heaxial sol enoi d t o cont rol t he hydraul ic flui d pres s ure s uppl ied t o t he clut ch pl ates. Some of t he modul es and s ens ors thecont rol module communi cat es wit h are li s ted below:
Hardwi red:- Control valve / axi al s olenoid- Electric hydrauli c pump- Oi l press ure and temperat ure sens orHigh speed CAN (cont rol ler area net work):- Engine cont rol module- Anti -l ock brake s ys t em / t racti on cont rol module- Tracti on res ponse swit ch- Y aw rate sens or- Steering wheel rot at ion sens or
The axial sol enoi d cons t ant ly adjust s t he cont rol valve output us ing a Pul se W i dt h Modulat ion (PW M) s i gnal. The flui dpres s ure deli vered t o t he cl utch plat es determines t he amount of t orque t hat is delivered t o t he rear axl e.
The act ive on-demand coupli ng has int egrated oi l press ure and temperature s ens ors to enable the control modul e t oaccurat ely manage t he t orque t ransfer under all environment al and operat ing condit ions . Usi ng thes e s ignals the controlmodule will us e s t rategi es to protect the coupli ng from overheati ng; in extreme cas es to protect t he coupli ng from damaget he coupli ng wil l dis engage i f the t emperat ure of t he hydraul ic flui d exceeds 105°C. The coupl ing wi ll ret urn to normalfuncti onal it y when t he temperat ure fall s below 101°C.
The cont rol module has an int egrated di agnos ti cs sys tem, whi ch cons tant ly moni tors the act ive on-demand couplings ys t em as wel l as it s input and output s ignals . If t he control modul e detects a fault a Diagnost ic Troubl e Code (DTC) i ss tored. The DTC is acces s ed usi ng t he Land Rover approved di agnos t ic s yst em.
Electric Hydraulic Pump
W hen negoti ati ng very low frict ion s urfaces s uch as wet gras s , snow or i ce; i nit ial wheel -s pin can cut i nt o t he s urface andreduce gri p. W it h a re-act ive on-demand coupl ing, almos t 60 degrees of wheel rotat ion woul d occur before torque could bet ransmit ted t hrough t he coupl ing.
On Generat ion 3 coupli ngs , t o count eract thi s Land Rover devel oped a uni que high-pres s ure pre-charge faci li ty whi chenergizes t he hydraul ic circui t as s oon as the engi ne is s t art ed. Es s ent ial ly an el ect ri cal ly operat ed hydraul ic pump wasdesi gned to maintai n a pot ent ial of 500 Nm (369 l b ft ) of t orque pres s ure wi thi n the coupli ng. (This pre-charge t orquecapacit y has been increas ed to 1500Nm (1106 l b ft ) for t he Generat ion 4 coupli ng.)
Vehicles fit ted wi th Terrai n Res pons e als o add furt her benefi ts by varying t he level of pre-charge t o deli ver opti mumt racti on over a range of di fferent t errai n s urfaces . The level of pre-charge is varied dependi ng on t he part icul ar terrainres ponse mode, for exampl e:
Terrai n respons e in 'Speci al Programs Off' mode as common wit h vehi cl es wit hout terrain res pons e, the coupli ng isprogrammed t o transmit 500 Nm 369 lb ft of t orque on Generat ion 3 couplings and 1500 Nm (1106 l b ft) of t orqueon Generat ion 4 couplings t o t he rear axle when the vehicle moves from res t i n a s t raight l ine. Thi s s trategymi ni mi zes t ract ion l os s from a s t andi ng-s tart regardles s of t he terrain. W hen the vehicle accelerat es the pres surein the coupling is decreas ed to improve fuel economy.The abili ty to sens e t he s teeri ng angl e all ows t he coupli ng t o be programmed t o provide no torque trans fer t hrought he coupli ng. This prevent s t he coupli ng locking when t he vehicle i s maneuvring at low s peeds and acute s teeri ngangl es.In 'Grass / Gravel / Snow' mode t he coupl ing i s programmed to maint ai n i ts pre-charge s t at e unt il much highers peeds are obtained. The s ame applies even i f the vehicle is t raveli ng at low speeds and acut e s t eering angles , ast racti on takes precedence over coupli ng lock-up on l ow-fri ct ion s urfaces .
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).
Mechanical Hydraulic Pump - Generation 3 Couplings - Vehicles up to 2009MY
The dri ves haft i s att ached t o t he coupl ing's front clut ch pl ate as s embly (i nput ), with the rear cl ut ch plat e as sembl yconnected t o t he different ial pini on (out put ). A s was h-pl ate wit h 6 hydrauli c rol lers is al so att ached t o t he different ialpinion. W hen there is no s peed difference bet ween the coupling's input and out put, the rol lers do not funct ion.

The parking brake is a manual ly appli ed cabl e s ys t em t hat operates brake s hoes, housed wit hin the i nner diamet er of eachrear brake di sc.
FRONT AND REAR DISC BRAKES
The 3.2L i 6 vehicle i s ins t al led wit h vent il ated front and rear brake di scs . The 2.2L TD4 vehicle is i nst all ed wit h venti latedfront and sol id rear brake dis cs. Bot h t he i6 and TD4 vehicl es feature s ingle pi s ton, s lidi ng cal ipers on all brake dis cs . Foraddi ti onal i nformat ion, refer to:
Front Dis c Brake (206-03 Front Di sc Brake, Des cri pt ion and Operati on),Rear Di sc Brake (206-04 Rear Di s c Brake, Des cri pti on and Operati on).
PARKING BRAKE
The parking brake is a manual ly appli ed, cable operat ed s yst em. The RH and LH rear brake dis cs form the parki ng brakedrums , and provide the l ocat ion for the parki ng brake s hoes and components .For addit ional informat ion, refer t o: Parking Brake (206-05 Parki ng Brake and Act uat ion, Descripti on and Operat ion).
HYDRAULIC BRAKE ACTUATION
Hydrauli c brake act uati on cons is t s of the brake pedal , mast er cyl inder, HCU, and t he connect ing hydraul ic pipes and hos es.
The t andem brake mas ter cylinder wit h reservoi r is at tached to, and operat ed by t he brake boos t er. The brake mas t ercyl inder is a tandem des ign t hat suppli es pres s ure t o 2 i ndependent (pri mary and secondary) hydraul ic circui ts .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).
BRAKE BOOSTER
The brake boost er is vacuum operat ed and provides power as s is t ance t o t he brake hydrauli c s ys t em. The boos t er i s oft andem des ign that incorporat es 2 s eparate diaphragms . On both the gas oline and di esel models , t he vacuum required forboos t er operat ion is produced by an engine driven, vacuum pump.For addit ional informat ion, refer t o: Brake Boos ter (206-07 Power Brake Act uati on, Des cript ion and Operat ion).
ANTI-LOCK CONTROL
The anti -l ock control sys tem feat ures a Cont inental Teves Mk25E1 ABS module wit h i ntegral 4 channel HCU. The ABSmodule and HCU provide brake sys tem monit ori ng, and acti ve brake funct ions t o cont rol t he vehi cl e s tabil it y and t racti on.The ABS module al s o provides s peci fi c functi ons to as s is t t he vehi cl e duri ng off-road drivi ng.
The anti -l ock control sys tem provides t he fol lowing funct ions :
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)Hil l Descent Cont rol (HDC) wit h gradi ent release cont rolRoll Stabi lit y Control (RSC)Terrai n Res pons e™ sys tem int egrati on.
For addit ional informat ion, 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).

brake boos ter.
5. Operate the engine for a minimum of 10 s econds at a fast i dle. Stop the engine and al low t he vehicle t o s t andfor 10 mi nut es. Then, appl y the brake pedal wi th approxi mately 89 N (20lb) of force. The pedal feel (brakeappli cat ion) s houl d be t he s ame as t hat not ed wit h t he engine runni ng. If the brake pedal feel s hard (no poweras s is t), ins t al l a new valve and t hen repeat t he tes t. If t he brake pedal s t ill feels hard, i ns t all a new brakeboos ter. If t he brake pedal movement feel s s pongy, bleed t he brake s ys t em.REFER t o: Brake Syst em Bl eedi ng (206-00 Brake Syst em - General Informati on, General Procedures ) /Brake Sys t em Pres s ure Bl eedi ng (206-00 Brake Syst em - General Informati on, General Procedures ).
5.
Brake Master Cylinder
Us ual ly, t he fi rs t and s tronges t indicat or of anything wrong i n t he brake s ys t em i s a feeling through t he brake pedal. Indiagnosi ng the condit ion of t he brake mas t er cyli nder, check pedal feel as evidence of a brake concern. Check for brakewarni ng lamp ill uminat ion and t he brake fluid level i n t he brake mas t er cyli nder reservoi r.
Normal Condit ions
The fol lowing condit ions are cons idered normal and are not i ndi cat ions t hat t he brake mast er cyl inder i s i n need of repair.
Modern brake sys tems are des igned t o produce a pedal effort that is not as hard as in the pas t . Compl aint s of lightpedal effort s s houl d be compared t o t he pedal efforts of another vehi cl e of t he s ame model and year.The fl uid l evel wi ll fal l wit h brake pad wear.
Abnormal Condi ti ons
Changes i n t he brake pedal feel or brake pedal travel are indicators t hat s omet hi ng coul d be wrong in the brake sys tem.The diagnost ic procedure and techni ques us e brake pedal feel , warning i ndi cat or il lumi nat ion and l ow brake flui d level asindicat ors t o diagnosi ng brake s yst em concerns . The foll owing condi ti ons are consi dered abnormal and indi cat e t hat t hebrake mas t er cyli nder i s in need of repai r:
• NOTE: Pri or to carrying out any diagnosi s , ens ure the brake sys tem warni ng indicator i s functi onal .
Brake pedal goes down fast . This could be caus ed by an external or int ernal leak.Brake pedal goes down s l owl y. Thi s coul d be caused by an int ernal or external l eak.Brake pedal is l ow or feels spongy. Thi s condit ion may be caus ed by no fl ui d i n the brake mas ter cylinder, reservoi rcap vent holes cl ogged or air i n t he hydraul ic s ys tem.Brake pedal effort is excess ive. This may be caus ed by a bi nd or obs t ructi on in the pedal/li nkage, a faul tynon-ret urn val ve, boost er or ins ufficient boos t er vacuum.Rear brakes lock up during light pedal force. Thi s may be caus ed by damaged brake pads , a parti ally appl ied parkingbrake, a damaged ABS s ens or or bearing fail ure.Brake pedal effort errat ic. This condit ion could be caus ed by the brake boos t er or incorrectl y ins tal led brake pads .Brake warning i ndi cat or is on. This may be caus ed by low fl uid l evel or fl oat as s embly damaged.
Non Pressure Leaks
Any reduced fl uid volume in t he brake mast er cyl inder res ervoi r may be caused by two types of none pres sure externalleaks .
Type 1: An ext ernal leak may occur at the brake mast er cyl inder res ervoir cap because of incorrect posi ti oning of t hegasket and cap. Repos it ion cap and gasket .
Type 2: An ext ernal leak may occur at the brake mast er cyl inder res ervoir mounti ng seal s. Repair s uch a l eak by ins tall ingnew s eals and make s ure that t he brake mas t er cyli nder reservoi r ret ai ning bolt i s correct ly i nst all ed.

ItemPart NumberDescription
1-Brake pipe t o LH front cali per2-ABS modul e
3-Brake pipe t o RH front cali per
4-Mas t er cyli nder primary circuit connect ion5-Brake pipe t o LH rear cal iper
6-HCU
7-Brake pipe t o RH rear cal iper8-Mas t er cyli nder s econdary ci rcuit connect ion
The HCU i s located on the rear LH s ide of t he engi ne compartment and i s an i nt egral component wit h t he ABS module. TheHCU i s a 4 channel uni t that modulat es the s upply of hydrauli c pres sure t o t he brakes under t he cont rol of the ABSmodule.
The pri mary and secondary outl et ports of t he mas ter cyli nder are connect ed via 8 mm (0.315 in) diamet er brake pipes t ot he primary and s econdary ci rcuit s of the HCU. The primary circui t in t he HCU provi des 2 s eparate out let port s t o t he RHfront and LH rear brakes . The secondary circuit in t he HCU provi des 2 s eparate out let port s t o t he LH front and RH rearbrakes.
The HCU i ncorporates 3 brake operati ng modes as fol lows :
Normal braki ng/ El ect ronic Brake Force Dis t ri but ion (EBD)ABS brakingActi ve braking.
As t he HCU and ABS modul e is a ful ly i ntegrat ed unit , the des cript ion and operat ion det ai ls for the HCU and ABSfuncti onal it y, i ncl udi ng t he 3 braking modes , are det ail ed in the Ant i-Lock Control - Stabil it y As si st secti on of the manual .For addit ional informat ion, refer t o: Anti -Lock Cont rol - St abi li ty As s is t (206-09 Anti -Lock Cont rol - St abi li ty As s is t ,Des cript ion and Operat ion).
Servicing Information
The ABS module and HCU form a s ingle component and must not be s eparat ed. The ABS modul e and HCU as s embly i ss uppl ied i n a pre-fill ed s tat e. Aft er i nst all at ion, t he hydraul ic brake sys t em only requi res a conventi onal bleed of t hes ys t em; t here is no requirement to press ure bleed t he s ys t em.
• NOTE: The ABS module and HCU i s a fragil e component and mus t be dis carded if dropped or damaged.
PRINCIPLES OF OPERATION
As t he brake pedal i s pres s ed, t he front push rod i n t he brake boost er pus hes t he mas ter cyl inder pri mary pi st on along t hebore of t he housi ng. This produces pres s ure in t he pri mary pres sure chamber and i n conjunct ion wi th the primary s pri ng,overcomes the s econdary s pring and s i mult aneous ly moves t he s econdary pi st on along the bore.
The ini ti al movement of the pi s tons away from the pi st on s t ops cl os es t he pri mary and secondary cent er val ves l ocat edins ide the mas t er cyli nder. Further movement of the pi st ons then press uri zes the flui d in the primary and s econdarychambers and t he brake circuit s . The fl uid i n t he chambers behi nd the pi s tons i s unaffected by the movement of the

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.

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