LAND ROVER FRELANDER 2 2006 Repair Manual

ItemPart NumberDescription
1-Met ering val ve2-Hous ing
3-Di aphragm
4-Temperat ure s ens or5-Out let pass age from evaporat or
6-Inlet pass age from evaporat or
The t hermos tat ic expans ion val ve meters the fl ow of refri gerant i nto the evaporator, to match t he refri gerant fl ow wi th t heheat load of the ai r pas s ing through t he evaporat or.
The t hermos tat ic expans ion val ve is a bl ock type valve l ocat ed behi nd the heat er as sembly, and att ached t o t he inl et andoutl et ports of t he evaporator. The t hermos t at ic expansi on valve cons i st s of an aluminum hous ing containi ng inlet andoutl et pas s ages . A ball and s pri ng met ering val ve is i nst all ed in the i nlet pass age and a t emperat ure s ensor i s ins t al led i nt he out let pas sage. The t emperature s ens or cons is t s of a t emperature s ens i ti ve tube connect ed to a diaphragm. Thebott om end of t he t emperature s ens it ive tube acts on the ball of t he met ering val ve. Pres s ure on top of t he diaphragm iscont rol led by t he evaporat or outl et t emperat ure conduct ed through the t emperat ure s ensi ti ve tube. The bott om of t hediaphragm sens es evaporat or out let pres s ure.
Liquid refrigerant flows t hrough t he metering valve i nto the evaporator. The res trict ion acros s t he metering valve reducest he pres sure and t emperature of the refrigerant . The res trict ion als o changes the l iquid st ream of refrigerant i nto a fi nes pray, to improve t he evaporati on proces s . As t he refri gerant pas s es through the evaporator, it abs orbs heat from t he airfl owing t hrough t he evaporat or. The i ncreas e i n t emperature caus es t he refri gerant to vapori ze and increas e in pres sure.
The t emperature and pres s ure of t he refri gerant l eavi ng the evaporat or act s on t he diaphragm and t emperat ure s ensi ti vet ube, which regul ate the met eri ng val ve openi ng and s o cont rol t he vol ume of refri gerant fl owing t hrough t he evaporat or.The warmer t he air flowi ng through the evaporator, the more heat avai lable to evaporat e refri gerant and thus t he greatervolume of refrigerant all owed through t he met eri ng val ve.
EVAPORATOR
The evaporat or is i nst all ed in the heater as s embly, bet ween t he blower and the heat er core, t o abs orb heat from t heexteri or or recirculat ed air. Low pres s ure, low temperat ure refrigerant changes from li qui d t o vapor i n t he evaporat or,absorbing l arge quant it ies of heat as it changes st ate.
Mos t of the moi s ture in the ai r pas s ing t hrough t he evaporat or condens es i nto wat er, whi ch drains out of the vehicl e bypass i ng through a drain tube t o t he unders ide of t he vehi cl e.
REFRIGERANT LINES
To mai nt ain si mil ar fl ow velocit ies around t he A/C s ys t em t he diamet er of t he refrigerant li nes varies t o s uit t he 2pres s ure/t emperat ure regi mes . Larger di ameter pipes are ins tal led i n t he low pres sure/t emperature regi me and s mall erdiamet er pi pes are i nst all ed in the hi gh pres sure/t emperature regi me.
Nylon l ined, low permeabi li ty rubber hos es are us ed i n t he low press ure li ne int o t he A/C compress or, and i n t he highpres s ure l ine from the condens er. The remainder of the refrigerant l ines are manufact ured from s teel.
Low and high press ure charging connecti ons are i ncorporated i nto the refrigerant li nes for s yst em s ervi ci ng.

CONTROL DIAGRAM
• NOTE: A = Refrigerant l iquid; B = Refrigerant vapor; C = Air flow
ItemPart NumberDescription1-Evaporat or
2-Thermos tat ic expans ion val ve
3-High press ure servicing connecti on4-Refrigerant pres s ure s ensor
5-Engi ne cool ing fan
6-Condens er7-Receiver/Drier
8-A/C compress or
9-Low pres s ure s ervi ci ng connect ion10-Cool ing fan
PRINCIPLES OF OPERATION
To accompl is h t he transfer of heat , the refrigerant is ci rculat ed around t he sys t em, where i t pas s es t hrough 2pres s ure/t emperat ure regi mes . In each of t he regimes the refrigerant changes s t at e, during which process maxi mum heatabsorpti on or di s si pat ion occurs .
The low pres sure/t emperature regi me i s from the t hermos tat ic expansi on val ve, t hrough t he evaporat or to the compres s or.The refri gerant decreas es in pres sure and t emperature at the thermos t ati c expans ion valve t hen changes s tat e from ali qui d t o a vapor in t he evaporator t o absorb heat.

The high press ure/temperat ure regime is from t he compres sor, through t he condens er and recei ver drier as sembl y to thet hermos tat ic expans ion val ve. The refri gerant increas es in press ure and temperat ure as it pas ses through t he compres sor,t hen releas es heat and changes s t ate from a vapor to a li qui d i n t he condenser.
Operat ion of t he A/C sys t em i s cont roll ed by t he Automat ic Temperat ure Cont rol (ATC) module.For addit ional informat ion, refer t o: Cont rol Component s (412-01 Cli mat e Cont rol , Descripti on and Operat ion).

Publishe d: 11-May-2011
Climate Control - Control ComponentsDescripti on a nd O pe ration
COMPONENT LOCATION
ItemPart NumberDe scription1-Refrigera nt press ure sens or2-Cabin humidi ty s ensor (if fitt ed)3-Air Condi tioning (A/C) compressor (i6 shown)4-Engine Coola nt Temperat ure (ECT) s ensor5-Ambi ent air t emperat ure sensor6-Air intake ste ppe r motor

7-P ollution sensor (if fi tted)8-W indshie ld distri buti on (defrost) ste pper motor9-Right Hand (RH) tempera ture ble nd s tepper mot or10-Sunload s ens or11-Cabin temperature se nsor12-Automati c Te mpe rature Cont rol (ATC) modul e13-Evaporator te mpe rature s ens or14-Left Hand (LH) te mpe rature blend st eppe r motor15-Blowe r motor control module16-Face/feet dis tribution ste ppe r motor17-Blowe r motor
OVERVIEW
The clima te cont rol s yste m i ncorpora tes the hea ting, ve ntila tion and A/C systems. There are 2 mai n types of clima te controls yste m a vail able ;
a single z one ma nual sys tema dua l zone a utomati c system.
The clima te cont rol f unct ions for bot h systems a re controlle d by the ATC modul e. The ATC module is mounted in the ce nte rcons ole a nd cont ains bot h the syste m e lectronic sof twa re a nd user cont rols .
The ATC module works in conjunction wi th a number of othe r ve hicle control module s, i ncluding the Engine Control Module(ECM), which control s a number of cl ima te control sub-s yste ms on recei pt of reques ts f rom the ATC module .
The s ingle zone climate cont rol s yst em f eat ures ma nual control for air t empera ture , air dist ribution and air source, although as mal l amount of aut oma tic control does exis t in the ATC softwa re. In re sponse to s yste m i nput s, t he ATC module cont rols theopera tion of 3 st epper motors mounted on t he heat er as sembly. The st eppe r motors then a djust the positi on of the ai rt emperat ure, air dist ribution and air source flaps accordingly.
The dual zone cl imat e control system fe atures a utomati c control of air t empera ture , air dis tribution and blower motor s pee d.The ATC module is a lso able to cont rol i ndividua l te mpe rature re que sts for both the dri ver a nd pass enger s ide of the cabin.
• NO TE: The ATC module can only maint ain a maximum tempera ture dif fere nce bet wee n the 2 side s of the cabin of up toa pproximate ly 3ºC (4ºF). This is due to the moveme nt a nd mix of a ir wi thin the cabin.
The dual zone cl imat e control system fe atures 2 additional sens ors; a cabin temperature se nsor and a sunload sensor. Thecabin temperature se nsor provides a temperature fe edback to e nabl e the ATC module s oftware mai ntai n a cons tant ca bint emperat ure. The sunloa d se nsor provide s a rea ding of s ola r loa ding on the vehicle occupants a nd enables the ATC module toa djus t the output from t he clima te control s yste m a ccordingly.
Higher specif icat ion vers ions of t he dual zone cl imat e control system are al so a vailable . These syst ems fea ture 2 morea ddit iona l se nsors; a polluti on s ensor and a cabin humidity sensor.
The pollution sensor det ects pol luta nts ente ring the cabin, allowing the ATC modul e to rea ct by cha ngi ng t he posit ion of thea ir intake fla p. The cabin humidi ty s ensor ca lcul ates the probability of misti ng on the winds hiel d. The ATC module monitorst he s igna l from t he cabin humidi ty s ensor and a djus ts blowe r speed, air dis tribution and A/C compress or di spla cementa ccordingly.
Stop/Start Vehicles - From 2010 MY
To support the Stop/Start system, a number of changes have be en made to the logic and opera tion of climate cont rol s yst emwithi n a Stop/Sta rt cycle to:
maint ain occupant comfortpreve nt winds hie ld mistingconse rve batt ery power.
This has bee n achieved by the ATC (automa tic t emperat ure control) module monitoring and varying when nece ssary, va riousclima te control funct ions wit hin a St op/Start cycle.For a ddit iona l inf ormation, re fer to: Starting Sys tem (303-06C Start ing Syst em - TD4 2.2L Diese l, Vehicles Buil t From:01-03-2009, Des cript ion and Ope rati on).
To maint ain the cabi n te mpe rature when the engine is s hut down in a St op/Start cycle, an a uxil iary electric coolant-pump hasa lso bee n int egra ted into the cooling system to mai ntai n the coolant flow t hrough t he cabi n’s heat er core. The pump isdirectly hardwire d to the ECM. O n ve hicl es fi tted wit h a FFH (fue l fired heat er), the FFH coolant pump i s uti lize d and activa tedvia t he FFH.For a ddit iona l inf ormation, re fer to: Starting Sys tem (303-06C Start ing Syst em - TD4 2.2L Diese l, Vehicles Buil t From:01-03-2009, Des cript ion and Ope rati on).
• NO TE: From 2010 MY , the 'ECO N' s witch will be la bele d ‘A/C’ t o prevent confusion wit h the ‘Eco’ s witch which ope rate s the‘Stop/Sta rt’ a nd 'Gea r Change Indica tor' syst ems .
ATC MODULE

The ATC module is mounted in t he cente r console a nd is int egra l wi th t he control panel . The modul e works in conjunct ion witht he ECM to control a ll as pect s of hea ting, ve ntil ation, and A/C. An 18-pin el ectrical connect or on the re ar of the moduleprovi des hardwired, Cont rolle r Area Network (CAN) bus a nd Loca l Interconne ct Network (LIN) bus conne ctions t o al lowi nteraction with A/C syst em components and other vehicle control modules.For a ddit iona l inf ormation, re fer to: Communicat ions Ne twork (418-00 Module Communi cati ons Net work, De scri ption andO peration).
Six different ATC module s (2 single zone , 4 dual zone) a re a vail able , de pending on vehicle spe cifica tion. Low s peci fica tionvehicles feat ure 3 rotary controll ers and 3 top hi nge d mome ntary switches t o control the qualit y, te mpe rature a nd dist ribut ionof ai r int o the ca bin. High specif icati on vehicles feat ure 3 rotary control lers, 6 top hinge d mome nta ry s witches, and 2 dualf unct ion moment ary swit che s to control the qua lity, tempera ture and di stribution of air into the cabin.
In additi on t o the A/C system, t he ATC module cont rols ope ration of:
The s eat hea tersThe rear window heat erThe winds hie ld he ate rThe e xterior mirror he ate rs.
For more informa tion, re fer t o the 'P rinci ples of O pe ration' s ection below.
COMPRESSOR SOLENOID VALVE
Ite mPart NumberDescription1-Compres sor sole noi d va lveThe compres sor sole noid val ve is int egra l wi th t he A/C compres sor. Ope rati on of the solenoid valve is cont rolle d by the ECMusing a P ulse W i dth Modulat ed (PW M) s igna l of diffe ring va lues . By controll ing the flow of refri gera nt (displace ment) t hrought he compress or, the sole noid va lve can cont rol e vaporat or opera ting temperature and cabin humidit y by va rying the pre ssurewithi n the A/C syste m.
• NO TE: The A/C compre ssor sol enoid va lve is fi tted to i6 petrol vehicle s only.
For a ddit iona l inf ormation, re fer to: Air Conditioning (412-01 Cli mat e Control, Description a nd O peration).
REFRIGERANT PRESSURE SENSOR

The refrigera nt press ure sensor provides the ECM wi th a pre ssure input from the high press ure side of t he refri gera nt s yste m.The pres sure sensor is locat ed in the ref rige rant line be twee n the conde nse r and the thermosta tic expa nsion valve .
The ECM supplie s a 5 V reference fe ed t o the pressure s ens or a nd recei ves a re turn signal volta ge, bet wee n 0 V and 5 V,relat ed t o system pressure. The ECM use s the s igna l from t he s ensor to protect the ref rigerant sys tem from extremes ofpress ure .
If the pre ssure withi n the re frige rant sys tem exceeds the minimum or maximum pre ssure li mits , the ECM will;
disable the A/C compress or (TD4 vehicles )re duce A/C compress or di spla cement (i6 vehi cles ).
If a reduction in A/C compre ssor displace me nt fa ils to bring the sys tem back into it's optimum pres sure range, the i6 ECM willdisable t he A/C compres sor.
The ECM constantly sends a refrigera nt s yst em pres sure signal to the ATC module. The signal i s tra nsmitte d from the ECM tot he Cent ral Junct ion Box (CJB) over the high spe ed CAN bus . The CJB acts a s a gate way and provides t he press ure signal t ot he ATC module over the me dium speed CAN bus.
If the pre ssure withi n the re frige rant sys tem rise s a bove its ma ximum press ure limit, the ATC module will incre ase thea mount of re circulate d a ir enteri ng t he cabin. This helps lower t he press ure wit hin t he refrigera nt s yste m a nd t hus helps toa void ha ving to disa ble t he A/C compres sor.
EVAPORATOR TEMPERATURE SENSOR
The e vaporat or t emperat ure sensor is a Negative Te mpe rature Coef ficie nt (NTC) the rmistor. The se nsor is mounted on the LHs ide of the heate r ca sing, and meas ures the temperature of cooled air once it has t rave led ove r the evaporator. The se nsorrecei ves a 5 V re fere nce feed from the ATC module. By monitori ng t he returned volt age , the ATC module ca n ca lcul ate theresis tance of the sensor and hence e vaporat or t emperat ure.
CABIN TEMPERATURE SENSOR

The cabin te mpe rature s ensor comprises a NTC thermist or a nd a motor. The sensor is mounted behind a grill on the driverss ide of the instrume nt panel , adjace nt t he s teering column.
• NO TE: The cabin te mperat ure sens or i s only fi tted to vehi cles with a dual zone, a utomati c cli mat e control system.
The motor is provide d an ele ctrical f eed from the ATC module and draws ca bin a ir in through the grill a nd over the thermis tor.The t hermist or re ceives a 5 V re fere nce feed from the ATC module. By moni toring the re turned volt age, the ATC modul e ca ncalculate air tempera ture wit hin the cabin.
CABIN HUMIDITY SENSOR
The cabin humidity s ens or is located wit hin the inte rior mirror a nd comprise s 3 individual el eme nts :
A humidit y se nsorAn ai r temperature se nsorA windshi eld glas s te mpe rature s ens or.
• NO TE: The cabin humidity sens or i s an opt iona l fit onl y.
The readings from these 3 s ensors combine to reduce the ri sk of mi sting on the windshield.
The humidity sensor element is cont aine d behind a nylon mesh cove r. The s ens or comprise s an ele ment made up of fil mcapa citors on dif fere nt s ubst rate s. The diele ctric is a polyme r which abs orbs or rele ases wa ter proportional to t he humidity oft he a ir being dra wn t hrough the sensor. This causes a change in the capacit ance of the sensor.
Humidity wit hin the cabi n is controll ed by ra ising or lowering the te mpe rature of the evaporator. An increas e in eva poratort emperat ure increase s the moist ure cont ent of t he a ir in the cabin. Lowering the evaporator tempe rature re duces t he mois tureconte nt of the ai r in the cabin.
The capa cita nce of t he s ensor, t oget her with both te mperat ure values, are provided as LIN bus me ssages t o the ATC module.The ATC module use s these signals to calculate the dew point of the ai r at the windshi eld. W hen t he t emperat ure of t hewindshie ld glass rea ches or falls bel ow t his value, misti ng i s likely to occur. In this inst ance, the ATC module will;
ra ise the tempera ture of the air l eaving t he heat er a ssemblya djus t the position of the windshield dis tribution (de fros t) s tepper motora djus t the position of the air inta ke stepper mot orre duce A/C compress or di spla cement (i6 only)powe r the windshield hea ter element s (if fitt ed).
AMBIENT AIR TEMPERATURE SENSOR

The a mbient air tempera ture sensor is a NTC thermi stor, and is mounte d in the LH door mi rror. The sensor rece ives a 5 Vreference fee d from the ECM. By monitoring the returned voltage, the ECM can calculate the res ista nce of t he s ens or a ndhence ambie nt a ir te mpe rature. The ECM tra nsmits an a mbi ent air t emperat ure value over t he high spe ed CAN bus . This va luei s rel aye d to the ATC module by the CJB ove r the medium s peed CAN bus.
SUNLOAD SENSOR
The s unl oad sensor i s mount ed i n the ce nte r of the inst rument pane l upper surf ace . The se nsor contains a photoel ectric ce ll,which provides the CJB with an i nput of light int ensi ty e qua ting to t he s olar hea ting eff ect on t he cabin.
The s ola r he ating va lue is transmitte d from the CJB to t he ATC module ove r the me dium speed CAN bus. The ATC modulecompens ates for the sola r he ating e ffect by adjusting blowe r speed, air out put tempera ture and air dis tribution to mai ntai nt he requi red cabi n te mpe rature.
POLLUTION SENSOR

The pollution sensor allows the ATC module to monitor inta ke a ir for the level of carbon monoxide (CO ) and oxides of nitrogen(NOx). The s ensor is mounte d on the RH side of the hea ter casi ng.
• NO TE: The poll ution se nsor is an optional fit on ve hicl es with a dual z one , automatic climate control syst em.
The pollution sensor is provi ded an i gnit ion cont rolle d fe ed from the Ba ttery Junction Box (BJB) and provide s one of thef ollowing 4 s igna ls t o the ATC module based on ambient air qua lity:
Static or reduced poll ution le velsSmall increas e in poll ution le velsMedium incre ase in pollut ion leve lsRapid or l arge increas e in pol lution le vels .
Base d on the signal from the polluti on s ens or, t he ATC module is a ble t o control the intake air source to re duce the amount ofconta minant s entering the cabin. This functi on i s fully a utomati c, but ca n be overridden by manual sele ction of the air inta kes ource us ing the fres h/re circulat ed a ir switch on the control panel.
CONTROL DIAGRAM
• NO TE: A = Hardwired; D = High Speed CAN bus; N = Medium Spe ed CAN bus ; O = LIN bus