
Publi s hed: 11-May-2011
Electronic Engine Controls - I6 3.2L Petrol -
ItemSpecification
Heated oxygen s ens or (H02S)removal *Apply W D40 or equi val ent
Heated oxygen s ens or (H02S)t hreadsApply s uit abl e high temperat ure ant i-s ei ze compound t o t hreads of sens or (Cas trolOpti mol)
* Apply to area around sensor threads prior to attempting to remove sensor
General SpecificationItemSpecification
Engine management system:
MakeDens oCamshaft position sensor:
MakeDens o
TypeMRE (hal l affect)Crankshaft position sensor:
MakeDens o
TypeVariable reluctance
Torque Specifications
DescriptionNmlb-ftCams haft  pos it ion (CMP) sens or bol t+107
Catal ys t  moni tor s ens or4533
Catal ys t  moni tor s ens or harnes s s upport  bol t65Cranks haft posi ti on (CKP) s ensor Torx bol t107
Engine control  modul e (ECM) bracket bolt s64
Flywheel sens or bol t107Flywheel sens or bracket  s crews107
Fuel rail  pres s ure s ens or65
Heated oxygen s ens or (H02S)++4533Knock sens or ret ai ning bolt2014
Mas s  air flow (MAF) s ens or Torx s crews21
+ Apply clean engine oil to a new CMP sensor O-ring seal
++ Apply anti-seize lubricant to threads of sensor - See Lubricants 

12-Res trai nts  Cont rol Module (RCM)
13-Knock sens ors  (2 off)
14-Fuel  rail  t emperature/pres s ure s ens or15-Clockspring
16-Terrain respons e cont rol  module
17-Trans mis s ion Cont rol Module (TCM)18-ABS module
19-Diagnos ti c socket
20-CJB
ENGINE CONTROL MODULE (ECM)
The ECM i s located on a bracket  i n a central pos i ti on on the engi ne compartment  firewal l. The ECM is  at tached to ahous i ng and s ecured wit h 4 s crews . The hous i ng is  l ocat ed in the bracket and locked in pos it ion.
The ECM i s s uppl ied wi th bat tery volt age from fuses  l ocat ed in the BJB. A permanent  batt ery s upply i s  provided t o ens ureadapt ive dat a is  not  l ost  when the engine i s  s wit ched off.
A regul ator, locat ed wi thin the ECM, s upplies  a 5V current  t o i nt ernal components  such as  t he mi cro-proces s or unit . Ot hercomponents  or funct ions  requi ri ng ful l bat tery vol tage are cont rol led by ext ernal relays  or int ernal power s t ages .
The mi cro-proces sor wi thi n the ECM receives  s ignals  from different  component s  and cont rol  modules  and us es  a programwit hin the ECM software t o int erpret  t he s ignal informat ion and i ss ue s ignals  whi ch rel at e t o how the engine component sand functi ons  should be cont rol led.
The ECM recei ves  i nput s  from the foll owing:
CMP s ensorsCKP s ensorFuel  rail pres s ure s ensorMAF s ensorKnock s ens orsFuel  rail t emperature/pres s ure s ensorECT s ens orEngi ne oil  l evel/t emperature s ens orManifol d Abs olute Pres sure (MAP) sens orElectric t hrot tl e - Throt tl e Posi ti on (TP) s ens orAPP s ens orFuel  t ank leakage monit oring modul e (NAS onl y)Cooling fan controlHeated Oxygen s ens ors  (HO2S)Stop lamp s wi tch (via Central Juncti on Box (CJB))Speed cont rol inhibi t swi tchInt ake Air Temperat ure (IAT) s ens orAmbient  Air Temperat ure (AAT) s ens orTrans mis s ion Cont rol Modul e (TCM).
The ECM s ends out puts  to t he followi ng:
Main relayAir Condit ioning (A/C) relayFuel  i njectorsIgni ti on coi lsEngi ne cool ing fan cont rolElectric t hrot tl eElectric fuel pump driver moduleVari abl e Cams haft  Timing (VCT) s olenoidsStarter rel ay cont rolVari abl e int ake manifol d control  valvesVari abl e inl et cam profile swit ching sol enoi d val vesTrans mis s ion Cont rol Modul e (TCM).
SENSORS
The ECM opt imi zes  engine performance by interpreti ng s ignals  from numerous  vehicle sens ors  and ot her i nput s. Some oft hes e s ignals  are produced by t he act ions  of t he dri ver, some are s uppli ed by s ens ors  locat ed on and around t he engine 

and s ome are s uppli ed by ot her vehicle s ys tems .
Camshaft Position (CMP) Sensor
Two CMP sens ors  are located i n t he camshaft hous ing at  t he Left  Hand (LH) end of the engine. The s ens ors  are l ocat ed ina hole in t he housi ng and are secured wit h a s crew. There i s  a CMP sens or for each cams haft .
The CMP s ensors  monit or the pos it ion of t he cams hafts  to es t abl is h i gni ti on t imi ng order, fuel  i njecti on triggeri ng and foraccurat e Vari able Cams haft  Ti ming (VCT) operati on. The ECM can al so use the CMP sensors  t o det ermi ne which cylinderhas a mi s fi re or knock us i ng the CMP s ignal  out put .
The CMP s ensor i s a Hal l-effect s ens or which s wi tches  a 5V s upply from the ECM on and off. The s uppl y is  s wi tched whent eet h machined onto a puls e wheel on the cams haft  pas s  by t he ti p of t he s ens or. The t eeth are of differing s hapes , s ot he ECM can determine t he exact  pos it ion of t he camshaft  at  any t ime. W hen one of the t eeth pas s es by t he sens or ti p, as ignal is  t rans mit t ed to the ECM which can vary between 0 and 5V. The si gnal  i s high when a toot h is  di rectl y adjacent  t ot he sens or and is  l ow when t he t oot h i s away from t he s ensor.
Failure of one or bot h of t he s ens ors  wil l res ul t in the ECM usi ng a default  map for i gni ti on t imi ng and knock cont rol  wi ll  bedis abled.
The ECM moni tors the sens or for correct functi on and can diagnos e and s t ore fault  codes  for s ens or fault s . Thes e can beret ri eved us i ng a Land Rover approved diagnos t ic s ys tem.
Crankshaft Position (CKP) Sensor
The CKP s ensor i s located on t he forward s ide of t he trans mi s si on t orque convert er hous ing, in li ne wit h t he engi nefl ywheel . The sens or is  s ecured wi th a bol t int o a bracket att ached t o t he gear housing. A reluctor ring i s fi tt ed t o t heouter diamet er of t he cranks haft fl expl at e and t he s ens or reacts  to the gaps  i n the reluctor ring t o det ermi ne engi ne s peedand posi ti on informat ion. The s ens or has  2 wi res  from the ECM s ens or ground and a feedback s ignal.
The CKP s ensor i s an inducti ve type s ensor which produces  a s i nus oidal out put vol tage s i gnal. Thi s vol tage i s  induced byt he proximi ty of t he moving reluctor ring gaps , whi ch exci te t he magneti c fl ux around t he ti p of t he s ens or when each gappass es . Thi s  output  volt age wil l i ncrease in magni tude and frequency as  t he engine speed ri ses  det ermi ned by an increas ein the s peed at which t he gaps on t he reluct or ring pas s  t he s ens or. The s i gnal voltage can be as  low as  0.1V at  lowengi ne s peeds  and up to 100V at  hi gh engi ne s peeds . The ECM does  not  react  t o t he output  volt age (unles s  t he vol tage i sextremely l ow or high), i nst ead it  meas ures  the t ime int ervals  bet ween each puls e (signal frequency). The s ignal  i sdetermined by t he number of gaps  pas si ng t he sens or, and t he s peed at  whi ch they pass. The reluctor ring has  2 gapsmi ss i ng to gi ve t he ECM a s ynchroni zat ion poi nt  and det ermi ne t he pos i ti on of the cranks haft. The CKP sens or si gnal  i sals o us ed for mis fi re det ect ion.
The s ignal produced by t he CKP s ensor i s crit ical to engi ne running. Failure of the sens or when the engine is  runni ng wil lres ult  i n t he engi ne s topping i mmediat ely. The engi ne can be res t arted us i ng s ignal s from the CMP s ens ors  but  t he engines peed will  be limit ed to 3000 rpm and the Mal functi on Indicator Lamp (MIL) will  be ill uminat ed.
The ECM moni tors the sens or for correct functi on and can diagnos e and s t ore fault  codes  for s ens or fault s . Thes e can beret ri eved us i ng a Land Rover approved diagnos t ic s ys tem.
Fuel Rail Pressure/Temperature Sensor 

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 

int o t he int ake manifol d.
Throt tl e Posi ti on (TP) Sensor
The TP s ensor i s hous ed i n t he elect ric t hrott le ass embly and is  us ed t o check t he posi ti on of the throt t le di sc. Twopermanent magnet s  i n t he sens or connect ed t o t he thrott le di sc affect  t wo Hall  effect sens ors . As  t he s pi ndl e i s rot atedt he magnet s  rot ate around t he Hall effect  s ensors  and produce offset  analogue s ignals  back t o t he ECM. The ECMcompares t hes e s ignals  to st ored values  t o ens ure t hat they s how an accurate throt tle dis c pos it ion. The offset  s i gnals  aret hat  one Hal l effect s ens or produces  a higher vol tage as  t he t hrott le angl e increas es and the ot her sens or produces  alower volt age as the throt tl e angle i ncreases .
The ECM performs a s elf t est  and a cal ibrat ion routi ne on the throt t le di sc pos it ion at  each igni ti on cycle. This  i s  achi evedby t he ECM poweri ng the damper mot or to full y clos e t he throt t le di sc and then ful ly open t he t hrott le dis c.
The ECM moni tors the DC damper motor and t he TP s ens or for faul ts  and can st ore fault  related codes. Thes e can beret ri eved us i ng a Land Rover approved diagnos t ic s ys tem.
Accelerator Pedal Position (APP) Sensor
The APP s ens or is  locat ed on t he accel erator pedal . The s ens or compris es  a pl ast ic hous ing whi ch cont ai ns t wopotenti ometers and an analogue/digit al convert er. The potent iomet ers  are connect ed to a common shaft which is  act uat edby movement of the accel erator pedal.
The APP s ens or provides  t he ECM and t he CJB wi th i nformati on rel at ing to t he pos it ion of t he accelerat or pedal . The ECMus es  this  informati on t o act uate the damper mot or i n t he electric t hrot tl e as sembl y t o move t he thrott le di sc to the correctangl e i n rel ati on to the pedal pos it ion.
The APP s ens or receives  a fus ed 12V s upply from t he CJB, whi ch is  controll ed by the ignit ion relay in the BJB. The CJB als oprovides  t he s ens or wit h a ground. The s ens or provi des  two out puts ; t he anal ogue output  i s  t rans mit ted di rectl y t o t heCJB, whi ch in t urn is s ues  the s ignal to the ECM on t he CAN bus , the s econd out put  is t he Puls e W idth Modul ati on (PW M)s ignal whi ch is  trans mi tt ed direct ly to t he ECM. Both the analogue and PW M s ignals  trans mi t the s ame pos it ionalinformat ion.
The ECM us es t he PW M si gnal  t o calcul ate the requi red pos it ion of t he electric t hrottl e dis c i n t he electric t hrot tl e. In t heevent  of a fail ure of t he PW M si gnal , the ECM uses  the analogue s ignal recei ved from t he CJB as  a replacement . If t heanal ogue si gnal  i s als o i ncorrect or mis s ing, the ECM li mit s  t he maximum engi ne s peed to 2000 rpm.
The PW M and the analogue s ignal are us ed for di agnos ing fault s wit h t he APP s ensor. If t he ECM det ect s a di fferencebetween t he analogue and PW M si gnal s a faul t code is  s t ored. The ECM wil l use the s ignal  wi th t he l owes t  value forelectric t hrot tl e cont rol . The APP s ens or pos i ti on and any st ored fault  codes  can be read us ing a Land Rover approveddiagnost ic s ys tem.
Heated Oxygen (HO2S) Sensors