2006 LAND ROVER FRELANDER 2 engine

The fuel rai l pres sure/t emperature s ens or is locat ed on t he LH end of t he fuel rai l. The ECM suppli es the combinedpres s ure and t emperat ure s ensor wi th a 5V reference volt age and a ground and meas ures t he ret urned s ignals for pres s ureand t emperature.
Fuel pres s ure
The fuel pres s ure s ens or i s a peizo res is tor t ype sens or. The s ensor receives a 5V reference vol tage from the ECM andproduces an anal ogue s i gnal of between 0 and 5V depending on the pres s ure sens ed. Low pres sure gives a l ow volt ageoutput and cons equent ly hi gh pres s ure gives a hi gher volt age output. The ECM uses t his press ure s ignal t o adjus t t he fuelpump module out put pres sure by s endi ng cont rol ling si gnal s t o the FPDM and for i nject or ti ming.
The ECM moni tors the fuel pres sure s ens or for faul ts and can st ore fault related codes. Thes e can be ret ri eved us i ng aLand Rover approved diagnos t ic s ys tem. Sensor operat ion can als o be checked us i ng a Land Rover approved diagnos t ics ys t em t o check fuel pres sure. If no fuel pres s ure is i n t he fuel rai l, t he s ens or wil l read and output at mospheri c pres s ure.
Fuel Temperat ure
The fuel t emperature s ens or is a Negat ive Temperat ure Co-efficient (NTC) sens or. The s ens i ng thermis t or el ementres is t ance decreas es as the sens or temperat ure increases . The ECM s upplies t he s ensor wi th a 5V reference volt age and aground and meas ures t he ret urned s ignal as a t emperature.
The res is t ance i n t he s ens or changes wi th fuel temperat ure. A l ow fuel t emperat ure wi ll res ult i n a hi gh volt age bei ngret urned t o t he ECM and high fuel temperat ure wil l return a l ow volt age reading of between 0 - 5V.
The ECM moni tors the fuel temperat ure sens or for fault s and can s tore faul t rel at ed codes . These can be ret rieved us ing aLand Rover approved diagnos t ic s ys tem. The ECM us es t he ECT t emperature s ignal as a default but only up to a maximumof 100°C (212°F).
Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor
The MAF/IAT s ensor i s located i n t he out let pi pe from t he air cleaner hous ing. The combined MAF/IAT funct ions areconnected t o t he ECM on separat e wi res . The sens or has an ext ended moul ding whi ch is l ocat ed in a cent ral posi ti on in theair flow through t he air cleaner hous ing out let pipe, t hrough which t he air flow and t emperat ure are meas ured.
Mas s Air Flow (MAF) Sensor
The MAF s ensor meas ures t he mas s of air being drawn int o t he engi ne. The ai r mas s is calculat ed by t he cool ing effect ofinl et ai r pas s ing over a 'hot fil m' element cont ained wi thin the s ens or. The higher the ai r fl ow, the great er the cooli ngeffect on the el ement whi ch in t urn lowers the el ect ri cal res i st ance of t he 'hot film' el ement. The ECM us es t his resi s tancevalue t o calcul ate the ai r mass or vol ume of air flowing i nto the engine.
The MAF s ensor receives a bat tery volt age supply vi a t he ECM and t he main relay. The ECM provi des a ground and a s i gnalpath for the res is tance s ignal from t he 'hot film' sens or. The analogue s ignal from t he MAF s ens or varies bet ween 0.5 and5V. Low air flow gi ves a low vol tage and hi gh air fl ow gi ves a high volt age.
The MAF s ignal is us ed by t he ECM t o det ermi ne:
t he correct fuel quant it y (injecti on peri od) t o mai ntain the correct ai r/fuel rat io required for correct operat ion of t heengi ne and t he cat alys ts

t he ignit ion t imingt he engi ne load.
The ECM moni tors the MAF s ens or for faul ts and can s t ore fault rel ated codes. Thes e can be ret ri eved us ing a Land Roverapproved diagnos t ic s yst em.
Int ake Air Temperat ure (IAT) Sens or
The IAT s ens or measures the temperat ure of t he i nt ake air entering t he engine. The sens or is a temperat ure dependantres is t or (t hermi st or). The thermis t or i s a NTC sens or element. The el ement resi s tance decreas es as t he s ens ort emperature increas es. The ECM suppli es the sens or wit h a 5V reference volt age and a ground and meas ures the returneds ignal as a t emperature.
The res is t ance i n t he s ens or changes wi th i ntake air t emperat ure. A l ow i nt ake air temperature wi ll res ult i n a hi gh vol tagebeing returned t o t he ECM and hi gh int ake ai r temperature wil l ret urn a low volt age reading of bet ween 0 - 5V.
The ECM moni tors the IAT s ens or for fault s and can s tore faul t relat ed codes . Thes e can be retrieved us ing a Land Roverapproved diagnos t ic s yst em. If the IAT s ensor fails , t he ECM us es a defaul t temperature val ue usi ng the fuel railpres s ure/t emperat ure s ensor.
Knock Sensors
Two knock sens ors are located on the front of t he engi ne and are each s ecured to threaded holes in t he engine cylinderblock wit h a bol t. The knock sens ors are us ed by t he ECM t o monit or combus ti on knocking or vibrati on generat ed byignit ion combus ti on. The knock s ens ors are each connected t o t he ECM via a t wis t ed pai r of wires which reduces electricalint erference di s rupti ng t he si gnal produced.
Each knock s ens or cont ains a pei zo-ceramic crys t al whi ch produces a vol tage when an ext ernal force appli es pres s ure orload on it . W hen t he engi ne is runni ng, compres s ion waves produced by t he combus t ion proces s, creat es pres sure waveswhich pas s t hrough the engine cyli nder bl ock. Thes e press ure waves are detected by the knock s ens ors and the defl ect ionof the crys t al caus ed by the pres sure waves caus es the sens ors t o produce an out put s ignal. The s i gnals are pas s ed to theECM whi ch compares them wit h s tored mapped s ignal s i n it s memory.
The ECM can t hen det ermine when t he correct combus t ion occurs i n indivi dual cyl inders . If incorrect combus t ion detonat ionis det ect ed, the ECM can retard t he ignit ion ti ming on that cyl inder for a number of combus ti on cycl es . The i gni ti on ti mingwil l be gradually ret urned t o it s opti mal s et t ings. If t he knock is st il l det ected the ECM wi ll i ncreas e t he i nject ion period,which has a cooli ng effect on t hat cyl inder.
The s ignals from the knock s ens ors are us ed i n conjunct ion wi th the CMP sens ors and t he CKP s ens or t o det ermi ne theignit ion cycle and t herefore i dent ify which cylinder is knocki ng. The ECM is programmed to us e i gni ti on maps bas ed on highqual it y 95-98 RO N fuel . If fuel of a poor qual it y s uch as 91 RON i s us ed the engi ne may s uffer from knock (pinking) for aperi od of ti me. The ECM is capable of l earning and adapti ng to the l ow grade fuel and wil l modi fy it s int ernal ignit ionmapping t o compens at e for t he low grade fuel . Thi s feat ure of t he ECM i s called adapt ion.
If one or bot h knock s ensors fai l or the s ignal becomes i mplaus ible, t he ECM wi ll cancel clos ed loop cont rol of t he ignit ions ys t em. The ECM wi ll us e a defaul t 's afe' ignit ion map to ens ure the pre-det onat ion does not damage the engine bys ett ing maxi mum retard cont rol on s park advance. The dri ver may not ice 'pinking' under certai n dri vi ng condi ti ons and alos s of performance. The ECM monit ors t he knock s ens ors for fault s and can st ore fault relat ed codes . Thes e can beret ri eved us i ng a Land Rover approved diagnos t ic s ys tem.
Engine Coolant Temperature (ECT) Sensor

The ECT s ens or is locat ed i n t he thermost at hous ing, on t he front of the engine, below t he i nl et manifol d. The ECT s ens oris a t hermis t or type s ens or us ed by the ECM t o monit or the engine coolant t emperature. The ECM uses t he t emperatureinformat ion for the foll owi ng functi ons:
regulat e t he inject ion peri ods et engi ne idle target s peedcont rol t he engi ne cool ing fan(s )determine operat ion of t he A/C compres sordetermine operat ion of t he purge valve and catal yt ic convert er heat ing funct ion.
The s ens or is a Negat ive Temperat ure Co-efficient (NTC) thermis tor element . The element res is t ance decreas es as thes ens or t emperature increas es. The ECM suppli es the sens or wit h a 5V reference volt age and a ground and meas ures theret urned s ignal as a t emperature.
The ECT s ens or is important to the correct running of t he engi ne as a richer mixt ure i s required at low engi ne cool antt emperatures for efficient s tarti ng and s mooth cold running. As t he engi ne cool ant temperat ure i ncreas es , the ECM usest he temperat ure si gnal from the sens or to l ean off t he fuel mi xt ure to maint ai n optimum emis s ions and performance.
The ECM moni tors the ECT sens or for faul ts and can s t ore faul t rel at ed codes . These can be ret ri eved us ing a Land Roverapproved diagnos t ic s yst em. If the ECT sens or fail s, t he ECM us es a defaul t val ue of 90°C (194°F). The electric fan cont rolmodule i s s ent a default coolant temperat ure val ue of 105°C (221°F) and s wit ches t he cooling fan on permanent ly.
Engine Oil Level/Temperature Sensor
The engi ne oil l evel/t emperature s ens or is locat ed on t he unders ide of t he engi ne and is secured i n t he engi ne oil pan wi th3 s crews and i s s eal ed wi th an O-ring s eal. The ECM suppli es the s ens or wit h a 5V reference volt age and two wires s uppl yt he temperat ure and oi l level si gnal s back t o t he ECM.
Two t ypes of engine oi l level /t emperat ure s ensor are us ed. On earli er model s a capacit ive oi l level s ens or i s fit ted and wasrepl aced by an ul trasound l evel s ens or on l at er models . The principl e of the temperat ure s ens or i s t he s ame in bot h s ens ort ypes . The sens ors can be i dent ified by di fferences in t he s ens or housi ngs ; t he capacit ive s ensor has t he electricalconnector moulded s quare t o t he bas e of the s ens or, t he ult ras oni c s ens or has the connect or moulded at a s li ght angle tot he bas e of t he s ens or.
The ECM us es both the oi l l evel and t emperature s ignals t o calculat e t he oil level. Temporary oil level changes caus ed byhil l driving or cornering are taken i nt o account by t he ECM us ing addit ional informat ion s uch as vehi cl e s peed and engi neload.
Engi ne Oi l Level Sens or - Capacit ance Type
The engi ne oil l evel s ens or compris es t wo capaci ti ve gauge el ement s . Thes e meas ure the resi s tance to elect rical currentpass i ng through t he engine oi l.
There are t wo capacit ors , one meas uring t he permit ti vi ty of t he oil and a second with t wo pl at es s et verti cal ly meas uri ngt he hei ght . The s econd capaci tor wil l have a proport ion of oil and ai r bet ween t he plates and s i nce t he permit ti vi ty of ai r isdifferent t o t hat of oi l, t he permi tt ivit y readi ng wil l change as t he level of oi l decreas es and the ai r between t he plat e gapincreas es. This permi tt ivit y readi ng is compared t o t hat of the oi l (t aken by t he first capaci tor) and an oil level is derived.
Engi ne Oi l Level Sens or - Ult ras ound Type

The engi ne oil l evel s ens or us es an ult ras oni c puls e, which is refl ect ed back from the s urface of t he oil . The ti me i t takesfor t his s i gnal t o ret urn t o t he s ensor i s turned int o a PW M s ignal and is s ent to the ECM. The ECM det ermi nes the ti met aken for the ul trasonic pul se si gnal t o be recei ved and calculat es it i nto an oil level fi gure.
Engi ne Oi l Temperat ure Sens or
The engi ne oil t emperature s ensor i s a Pos it ive Temperat ure Co-effi ci ent (PTC) thermis t or el ement . The element res i st anceincreas es as t he sens or temperat ure decreas es. The ECM s uppli es t he sens or wit h a 5V reference vol tage and a ground andmeas ures t he ret urned s ignal as a t emperature. A low oil temperature wil l res ult in a l ow volt age bei ng ret urned t o t heECM and hi gh oil temperature wil l ret urn a hi gh volt age reading.
The ECM moni tors the engine oi l level/temperat ure sens or for fault s and can s tore faul t rel at ed codes . These can beret ri eved us i ng a Land Rover approved diagnos t ic s ys tem. If the sens or fail s , the ECM us es t he engine cool ant temperat ures ens or s ignal val ue as a s ubst it ute.
Manifold Absolute Pressure (MAP) Sensor
The MAP s ensor i s located i n t he lower part of t he int ake manifol d. The MAP s ens or meas ures t he abs olut e pres s ure in t heint ake manifol d. The sens or is a semi -conduct or type s ens or which responds t o pres s ure acti ng on a membrane wi thin thes ens or, al tering t he output volt age. The s ens or receives a 5V reference vol tage and a ground from t he ECM and returns as ignal of bet ween 0.5 - 4.5V t o t he ECM. A low pres sure ret urns a low vol tage s ignal to the ECM and a high press ureret urns a hi gh volt age.
The MAP s ensor det ect s quick pres s ure changes i n t he int ake mani fol d aft er the el ectri c thrott le. The s ignal is us ed inconjunct ion wi th the MAF sens or si gnal t o calculate the injecti on peri od.
The ECM moni tors the engine MAP s ens or for faul ts and can st ore fault related codes. Thes e can be ret ri eved us i ng a LandRover approved diagnost ic sys tem. If t he s ens or fai ls , the ECM uses t he MAF/IAT s ensor s i gnal value as a subs ti tut e.
Electric Throttle
The electric t hrot tl e is locat ed at t he entrance of t he int ake manifol d and is secured t o t he manifold wit h four Torx headbolt s. The t hrot tl e als o provi des for t he connect ion of t he air cleaner hous ing out let pipe which is secured t o t he t hrott lebody wit h a cl ip.
The electric t hrot tl e compri ses t he t hrott le body, a round throt t le di sc whi ch is act uat ed by a damper mot or and a thrott leposi ti on s ens or. The el ect ri c thrott le is control led by the ECM and recei ves pos i ti onal s ignals from the TP s ens or. If afai lure of the mot or occurs , t he thrott le di s c is returned to it s cl osed pos it ion by the s prings, wi th li mit ed engine s peedavai lable to the driver.
Spindle Damper Mot or
The mot or i s a DC damper motor which drives a gear wheel and t wo s pri ngs ; one for opening and one for cl osi ng. Themot or rotat es the spi ndl e t o which t he t hrott le dis c is at t ached. PW M s i gnals from the ECM control the damper mot or t oadjus t the pos it ion of t he t hrott le dis c, regul ati ng the amount of air ent ering the i nlet manifold for combus ti on.
Movement of t he mot or is achieved by changing t he polarit y of the power s uppl y to the DC mot or, all owing i t to beoperated in bot h direct ions . The throt tl e dis c and t he mot or has two maxi mum pos it ions ; t hrott le di s c cl osed which all owsmi ni mal air flow t hrough t he electric t hrot tl e int o t he int ake manifol d and t hrott le dis c open which all ows maximum air flow

Four HO2S are us ed by t he ECM t o meas ure t he oxygen content of t he exhaus t gas s es leaving t he engine. Two upst reams ens ors measure t he gas s es before they pas s t hrough the cat al yti c convert er and two addi ti onal downst ream s ens orsmeas ure t he gass es after t hey have pas sed through t he catalyt ic converter.
The HO2S receive a fus ed power supply from t he main rel ay in t he BJB. Each HO2S i s als o connect ed to the ECM on t hreewires which provi de a PW M cont rol of t he s ens or heat ing coil , a ground and a si gnal l ine.
HO2S Preheati ng
The HO2S (oft en referred to as a Lambda (λ) s ensor) only operat es efficientl y at temperatures above 300°C (572°F). Thenormal operat ing t emperature is bet ween 300°C and 850 °C (572°F and 1562°F) and the HO2S is el ect ri cal ly preheat ed s oit reaches t he opti mum working t emperature quickly. Anot her reas on for t he preheat ing is t o mai ntain a normal operat ingt emperature to prevent condens ati on which could damage t he s ensor.
The s ens or heat ing coi l i s a PTC res is tor. The heat ing coil i s s uppl ied wi th bat tery volt age vi a t he main relay and provi dedwit h a ground by t he ECM. W hen t he ECM provides t he ground t he current wi ll pass through t he coil . W hen t he sens or iscol d, the res is tance t hrough the PTC res is tor i s low and a high current wil l pas s t hrough t he coi l. The ECM provi des a PW Mground i ni ti ally. As t he PTC resi st or heat s up t he res i st ance increases reduci ng the current fl ow. Thi s is sens ed by t he ECMwhich graduall y reduces the PW M ground to a cont inuous ground.
The coi l is heat ed immedi ately foll owing an engine st art for a peri od of approxi mately 20 s econds and als o duri ng low loadcondi ti ons when the t emperat ure of t he exhaus t gas s es is ins uffi cient to maint ai n t he opti mum s ens or t emperat ure. TheECM controls t he appl icati on of the PW M s i gnal t o prevent sens or damage due t o t hermal s hock caus ed by the sens orheat ing too quickly. The ECM can diagnos e fault s i n t he heat er coi l and record faul t codes whi ch can be ret rieved us ing aLand Rover approved diagnos t ic s ys tem.
Ups tream HO2S
Two ups tream HO2S are us ed and are l ocat ed in each exhaus t mani fold, between the engine and t he catalyt ic converter.The HO2S compri ses a s ol id el ect rol yt e Zi rconium di oxi de cel l s urrounded by a gas permeabl e ceramic. The output volt agefrom the s ensor i s dependent on the level of O2 pas s ing t hrough t he permeable ceramic coat ing. Nomi nal volt age for λ=1is 300 to 500mV. As t he fuel /ai r mixt ure becomes ri cher (λ<1) t he volt age ri ses t o up t o 900mV. As t he mi xt ure becomesweaker (λ>1) the volt age fal ls t owards 0mV.
The upst ream HO2S i s used by the ECM to monit or t he oxygen content of t he exhaus t gas s es leaving t he engine beforet hey reach the catal yt ic convert er. The ECM wi ll check t he output from the HO 2S to det ermi ne t he combus t ion mi xture andensure λ=1 i s obtained. λ=1 is the opt imum air/fuel rati o which relat es to a mi xt ure of 14.7 kg air per 1 kg of fuel(14.7:1).
The HO2S us es current regul at ion and out put s a linear s ignal dependent on t he rati o of exhaus t gas oxygen to ambientoxygen. The oxygen cont ent of the exhaus t gas ses is meas ured by compari ng it wit h ambient air drawn int o t he HO2S.
Downst ream HO2S
Two downs tream HO2S are us ed and are l ocat ed in the each exhaus t s ys t em after t he s tarter cat alyt ic converter. Thedownst ream HO2S are used by the ECM to moni tor t he oxygen content of the exhaust gass es leaving t he cat alyt icconvert er. The ECM can us e t his i nformati on to check (when the condit ions for catal ys t diagnost ics have been met ) forcorrect operati on of the cat alyti c convert er.

Two CPS s olenoids are located at each end of the cyli nder head, adjacent t o t he inlet cams haft and are each s ecured wi tha bolt . The CPS s olenoids s uppl y oil pres s ure t o t he hydrauli c tappet locki ng pins al lowing t he cams haft profile to bechanged. Each s olenoid controls t he oil press ure supply to the hydrauli c tappet locking pins on 3 cyl inders .For addit ional informat ion, refer t o: Engi ne - 3.2L (303-01, Descripti on and Operat ion).
The CPS s olenoids receive a fus ed batt ery s upply via the main relay. The ECM provides a ground for t he s ol enoi d, whichact uates a val ve wit hin t he s olenoid al lowing oi l pres sure t o adjus t the cams haft profil e.
The ECM can diagnose the operat ion of t he CPS s olenoids and s t ore faul t rel at ed codes . The codes can be read us ing aLand Rover approved diagnos t ic s ys tem.
Ignition Coils
Six pl ug top coi ls are used on the i6 engine and are located in reces s es in t he t op of the cyli nder head. The coi ls arecont rol led by t he ECM and recei ve a fus ed, bat t ery volt age s upply vi a t he main rel ay. The ECM controls t he s park t imingand product ion by swit ching the primary circuit of each coil to ground all owing t he charge which has buil t up in the coil t oproduce a s park at t he s park plug.
Each coi l contai ns a power st age which controls t he pri mary current and the ECM s ends a si gnal t o each coi l to operat e t hepower st age s wit chi ng at the appropriate ti me. Each coil has a feedback wi re to t he ECM whi ch all ows the ECM to diagnos eeach individual coi l and st ore fault related codes. The codes can be read us ing a Land Rover approved diagnos t ic s yst em.
A s uppres sor i s mounted on the cams haft cover adjacent to ignit ion coil 3 t o prevent int erference from t he coi ls and/or t heinject ors affecti ng audi o operat ion.
Fuel Injectors
Six fuel injectors are us ed on the i 6 engine and are located on t he i nl et s ide of t he cyl inder head. The inject ors are s eal edin the cyli nder head wi th O -ring s eals and held in pos it ion by the fuel rail .

The inject ors recei ve a fus ed bat tery vol tage s upply via the main relay. The ECM operates t he i nject ors by groundi ngs olenoi d valves in the injector. W hen t he ground is appl ied t he s olenoi d valve operat es and the injector s prays pres s uri zedfuel from the fuel rail i nt o t he cyl inder int ake ports . The amount of fuel injected and the t iming of t he inject ion peri od iscont rol led by t he ECM us ing dat a from other s ens ors .
The ECM can monit or the injector operat ion by moni toring t he ground l ine from the i njector. Each i njector can be diagnosedby t he ECM and faul t codes s t ored. The codes can be read us ing a Land Rover approved diagnos t ic s ys tem.
Variable Intake System (VIS)
The VIS changes the length of t he inl et manifol d us ing t wo ECM controll ed act uators which move flaps t o cont rol t he airfl ow. The act uators operate s i ngul arly or t oget her to adjust t he l engt h of the inlet t ract.
Us ing an 'H' bridge, the intake and pl enum act uator's i nt ernal electroni cs changes the act uat or motor's polarit y andt herefore the flap pos it ion. At each fl ap pos i ti on change, the DC act uator mot or i s powered for approxi matel y 0.5 seconds .The worm gear des ign ens ures t hat the flap remains in t he desi red pos it ion, even when the el ect ri c mot ors are notpowered.
Int ake Tract Variabl e Manifol d
The ECM controls t he posi ti on of the flaps by modul at ing the relevant act uat or's cont rol s ignal. If the s ignal s hi ft s from low(approxi mately 1 volt ) to hi gh (approxi matel y 10 volt s) t he i nt ernal electroni cs interpret i t as the flap must cl os e. If thes ignal shi ft s from hi gh to low, t he fl ap mus t open.
At engi ne s peeds of l es s t han 3800 rpm both the i ntake and plenum flaps are clos ed. At engine s peeds of approxi matel y3800 rpm and higher the i ntake flap begins t o open, effecti vel y s hort eni ng the length of t he int ake manifol d. At engi nes peeds of 4800 rpm or higher bot h t he int ake and plenum flaps are open, providi ng the short es t length of i ntake manifold.
VIS Flap Functionality
Engine SpeedIntake T ract FlapPlenum Intake FlapEffectLess than 3800 rpmClos edClos edLong tract s
3800 t o 4800 rpmOpenClos edShort t racts
More than 4800 rpmOpenOpenOpen plenumPlenum Variable Int ake Mani fold
The ECM di agnos es vi a t he act uator i f the flap has as s umed the correct pos i ti on. It does this , by compari ng the des ired airfl ow wi th the act ual air flow. A fault code is st ored i f the deviat ions are outs ide t he t olerances. The codes can be readus ing a Land Rover approved di agnos ti c s ys t em.
If an act uat or fai ls and t he flap i s in the open pos it ion, it i s not pos s ible to remove t he act uator and flap as sembl y fromt he inlet mani fold. A smal l indentat ion on t he body of the actuat or al lows for a 3 mm Al len key t o be pus hed through t het hi n membrane wall of the act uat or hous ing. The All en key can be engaged i n t he spi ndl e of t he act uat or mot or whi chall ows the flap to be turned to the clos ed pos it ion and cons equent ly the actuat or and flap as s embly can t hen be removedfrom the i ntake manifold.
Purge Valve

The purge valve i s located on a bracket on the i nlet manifold, above the el ect ri c throt t le. The val ve has a hos e connecti onon t he bott om whi ch connect s i nt o t he electric t hrot tl e and all ows t he fuel vapors to be drawn i nto the i nlet manifold. Alarger connect ion on t he s ide of t he valve i s connect ed via a pipe t o t he evaporati ve (EVAP) emis s ion canis ter whi ch islocated i n t he LH wheel arch behind t he li ner.
The purge valve controls t he flow of fuel vapor from t he EVAP cani st er to the engine intake mani fold. Vacuum in the intakemanifold draws the vapor from t he canis ter once the purge val ve is open and burns the vapor as part of the combus ti onprocess .
The ECM controls t he operati on of the purge val ve when engine operat ing condi ti ons are correct t o add t he fuel vapor t ot he combus ti on process . The valve i s an electro-magnet ic s olenoid valve whi ch receives a fused bat tery vol tage s upply vi at he main relay. The ECM us es a PW M ground t o cont rol t he operati on of the val ve. By al tering t he frequency of the PW Mground s ignal, t he ECM can cont rol t he rat e at whi ch val ve is open. Thi s all ows the ECM to precis ely control t he amount offuel vapor pas si ng from the EVAP canis ter.For addit ional informat ion, refer t o: Evaporat ive Emi s si ons (303-13, Des cript ion and Operat ion).
The ECM can diagnose fault s wi th the purge val ve and s tore fault relat ed codes . The codes can be read us i ng a Land Roverapproved diagnos t ic s yst em.
Fuel Tank Leakage Monitoring Module (NAS only)
The fuel t ank leakage moni toring module is l ocat ed in the LH rear wheel arch, adjacent to t he EVAP canis ter. A port on t hes ide of t he module provi des for t he att achment of a dus t fi lt er, t hrough which fres h air i s drawn i nto the EVAP canis ter. Aport on t he unders ide of t he module i s connected by a s hort curved hos e to t he EVAP canis ter. Thi s connecti on allows fres hair t o be drawn int o t he cani st er during t he purge proces s and als o al lows t he s yst em to be pres surized by t he module forleakage tes t ing.
The fuel t ank leakage moni toring module receives a fus ed bat tery vol tage s upply via the main relay. The modul e i sconnected t o t he ECM whi ch provides a ground for the modul e when l eak det ect ion i s required.
The fuel t ank leakage moni toring module compris es an elect ric ai r pump, a s olenoi d valve and a heat er el ement. The airpump i s used to press urize t he EVAP s ys t em for leak tes t ing. The sol enoi d valve is normall y open, but clos es whenenergized by t he ECM t o clos e t he s ys t em t o al low i t to be pres s urized. The PTC heater element is us ed t o warm t he pumpbefore operati on.
The fuel t ank leakage moni toring s yst em periodicall y checks the EVAP sys tem and t he fuel tank vent s ys t em for leakswhen t he ignit ion i s off. The s ys t em can als o be act ivated for a diagnos ti c check by t he ECM.
The ECM checks for leaks in t he s yst em by operati ng the ai r pump in the fuel tank leakage monit ori ng modul e. The modul eair pump i s acti vat ed and t he ECM monit ors the current draw on t he air pump motor. A reference ori fi ce is provi ded in t hemodule whi ch allows the ECM to make a comparis on and es t abl is h a reference figure for meas uring the current draw on theair pump motor when air i s pumped through the orifice.For addit ional informat ion, refer t o: Evaporat ive Emi s si ons (303-13, Des cript ion and Operat ion).
The ECM can diagnose fault s wi th the ai r pump and the sol enoi d val ve and s tore faul t relat ed codes . Thes e codes can beread us ing a Land Rover approved diagnos t ic s ys tem.
Speed Control Inhibit Switch