LAND ROVER DISCOVERY 2002 Workshop Manual

HEATING AND VENTILATION
80-30REPAIRS
Refit
1.Connect engine coolant hose to heater return
pipe and secure with clip.
2.Position heater return pipe to cylinder block and
secure with bolt.
3.Secure engine harness and vacuum pipe to
heater return pipe and secure with clips.
4.Fit and tighten bolt securing heater return pipe
to heater feed pipe.
5.Connect heater return hose to heater return
pipe and secure with clip.
6.Refill engine coolant.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
Fuel burning heater - (FBH) - Td5
$% 80.40.01.99
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Clamp feed and return coolant hoses at FBH.
4.Position container to collect spillage.
5.Release clips, disconnect coolant feed and
return hoses from FBH.
CAUTION: Before disconnecting or
removing components, ensure the
immediate area around joint faces and
connections are clean. Plug open
connections to prevent contamination.
6.Disconnect 2 multiplugs from FBH.

HEATING AND VENTILATION
REPAIRS 80-31
7.Position container to collect spillage and
disconnect quick release fuel pipe from FBH.
CAUTION: Before disconnecting any part of
the fuel system, it is imperative that all dust,
dirt and debris is removed from around
components to prevent ingress of foreign
matter into fuel system.
8.Remove Torx bolt securing FBH to bulkhead
mounting bracket.
9.Release and remove FBH.
10.Collect locating bushes from pegs.Refit
1.Fit bushes to pegs.
2.Align FBH to pegs, fit Torx bolt and tighten to 25
Nm (18 lbf.ft).
3.Clean quick release connection and fit fuel pipe
to FBH.
4.Connect multiplugs to FBH.
5.Connect coolant hoses to FBH and secure with
clips.
6.Release clamps from hoses.
7.Connect battery earth lead.
8.Fit and secure battery cover.
9.Top-up cooling system.

+ MAINTENANCE, PROCEDURES,
Cooling system.

HEATING AND VENTILATION
80-32REPAIRS

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-1
AIR CONDITIONING DESCRIPTION AND OPERAT ION
A/C refrigerant system component
layout
Diesel installation shown, V8 similar
1Evaporator and thermostatic expansion valve
2High pressure servicing connection
3To rear A/C system (where fitted)
4Low pressure servicing connection
5Refrigerant lines
6Receiver drier
7Condenser
8Compressor

AIR CONDITIONING
82-2DESCRIPTION AND OPERATION
A/C control system component layout
RH drive shown, LH drive similar
1Air temperature control ECU
2Heater coolant temperature sensor
3Evaporator temperature sensor
4Dual pressure switch
5Ambient temperature sensor
6Sunlight sensor
7In-car temperature sensor

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-3
Description
General
The air conditioning system controls the temperature, distribution and volume of air supplied to the vehicle interior to
provide a comfortable cabin environment. The system is electronically controlled and features automatic and manual
modes of operation, with separate temperature control of the LH and RH air outlets. The automatic modes provide
optimum control of the system under most ambient conditions and require no manual intervention. The manual modes
allow individual functions of automatic operation to be overridden, to accommodate personal preferences.
The air conditioning system consists of a refrigerant system, a heater assembly and a control system. It also uses the
same air inlet duct and distribution ducts as the Heating and Ventilation system on non air conditioned vehicles.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.
Fresh or recirculated inlet air flows into the heater assembly from the blower in the air inlet duct. In the heater
assembly, the air is cooled and/or heated, depending on the selected cabin temperature and ambient conditions, then
directed to selected air outlets.
On vehicles with rear air conditioning, additional cooling is provided by recirculating air through a second evaporator
and distributing it to outlets in the roof.

+ AIR CONDITIONING, DESCRIPTION AND OPERATION, Description.

AIR CONDITIONING
82-4DESCRIPTION AND OPERATION
Refrigerant system
Schematic of air conditioning system
1Evaporator
2Thermostatic expansion valve
3Low pressure servicing connection
4Outlet to rear A/C system (where fitted)
5Dual pressure switch
6Receiver drier
7Cooling fan
8Condenser
9Compressor10Inlet from rear A/C system (where fitted)
11High pressure servicing connection
12Air flows
aAmbient air
bCooled air
cAmbient air through condenser
13Refrigerant
aLiquid
bVapour
The refrigerant system transfers heat from the vehicle interior to the outside atmosphere to provide the heater
assembly with dehumidified cool air. The system comprises a compressor, condenser, receiver drier, thermostatic
expansion valve and evaporator, joined together by refrigerant lines. The system is a sealed, closed loop, filled with
a charge weight of R134a refrigerant as the heat transfer medium. Oil is added to the refrigerant to lubricate the
internal components of the compressor.

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-5
To accomplish the transfer of heat, the refrigerant is circulated around the system, where it passes through two
pressure/temperature regimes. In each of the pressure/temperature regimes, the refrigerant changes state, during
which process maximum heat absorption or release occurs. The low pressure/temperature regime is from the
thermostatic expansion valve, through the evaporator to the compressor; the refrigerant decreases in pressure and
temperature at the thermostatic expansion valve, then changes state from liquid to vapour in the evaporator, to absorb
heat. The high pressure/temperature regime is from the compressor, through the condenser and receiver drier to the
thermostatic expansion valve; the refrigerant increases in pressure and temperature as it passes through the
compressor, then releases heat and changes state from vapour to liquid in the condenser.
Compressor
1Pulley
2Inlet connection
3Outlet connection
4Pressure relief valve
5Clutch connector
The compressor circulates the refrigerant around the system by compressing low pressure, low temperature vapour
from the evaporator and discharging the resultant high pressure, high temperature vapour to the condenser.
The compressor is attached to a mounting bracket on the engine, and is a ten cylinder swash plate unit with a fixed
displacement of 177 ml/rev (0.19 US qt/rev). The auxiliary drive belt drives the compressor via a pulley and an
electrically actuated clutch. Operation of the clutch is controlled by the Engine Control Module (ECM).
To protect the refrigerant system from unacceptably high pressure, a pressure relief valve is installed in the outlet side
of the compressor. The pressure relief valve is set to operate at 34.3 to 41.4 bars (497 to 600 lbf.in
2) and vents excess
pressure into the engine compartment.

AIR CONDITIONING
82-6DESCRIPTION AND OPERATION
Condenser
1Condenser matrix
2Outlet connection
3Inlet connection
The condenser transfers heat from the refrigerant to the surrounding air.
The condenser is installed immediately in front of the oil coolers. Rubber mounting bushes are used to mount the
condenser to the chassis sidemembers and brackets on the headlamp panels.
Ambient air, passing through the condenser matrix due to ram effect and/or the cooling fan, absorbs heat from the
refrigerant, which changes state from a vapour to a liquid.

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-7
Receiver drier
1Dual pressure switch
2Inlet connection
3Housing
4Outlet connection
5Outlet tube
6Screen
7Desiccant
The receiver drier removes moisture and solid impurities from the refrigerant and also acts as a refrigerant reservoir.
The receiver drier is clamped to a bracket in front of the condenser. The receiver drier housing is manufactured in
aluminium and contains a desiccant to absorb moisture. A mesh screen in the housing removes solid impurities. Inlet,
outlet and dual pressure switch connections are located in the top of the housing.
Liquid refrigerant enters the receiver drier, passes through the desiccant and mesh screen, and through a tube to the
outlet connection.