fuel type LAND ROVER DISCOVERY 2002 Service Manual

FUEL DELIVERY SYSTEM - V8
DESCRIPTION AND OPERATION 19-2-7
The fuel pump is a 'self priming' wet type pump which is immersed in fuel in the tank. The fuel pump operates at all
times when the ignition switch is in position II. If the engine is not started, the ECU will 'time-out' after 2 seconds and
de-energise the fuel pump relay to protect the pump. The pump receives a feed from the battery via fuse 10 in the
engine compartment fusebox and the fuel pump relay. The relay is energised by the ECM when the ignition switch is
moved to position II.
The fuel pump is retained with a locking ring and sealed with a rubber seal. The locking ring requires a special tool
for removal and fitment. An access panel for the fuel pump is located in the loadspace floor below the loadspace
carpet. The access panel is sealed to the floor with a rubber seal and retained by six self-tapping screws.
The fuel gauge sender is integral with the fuel pump. The sender is submerged in the fuel and is operated by a float
which moves with the fuel level in the tank.
Fuel pump
The fuel pump assembly comprises a top cover which locates the fuel pressure regulator, electrical connector and
fuel pipe coupling. The top cover is attached to a plastic cup shaped housing by two metal springs. The housing
locates the pump and the fuel gauge sender unit.
The lower part of the housing is the swirl pot, which maintains a constant fuel level at the fuel pick-up. A feed pipe
from the pump to the coupling connection and a return pipe from the regulator connect between the top cover and the
housing.
A coarse filter is attached to the base of the housing and prevents the ingress of large contaminants into the swirl pot.
A gauze filter prevents particles entering the fuel pump.
Surrounding the pump is a large fine paper filter element which further protects the fuel pressure regulator, engine
and injectors from particulate contamination. The paper filter is not a serviceable item and removes the requirement
for an external in-line filter.
A non-return valve is located in the base of the housing. When the fuel tank is full, fuel pressure keeps the valve lifted
from its seat allowing fuel to flow into the swirl pot. As the tank level reduces, the fuel pressure in the tank reduces
causing the valve to close. When the valve is closed fuel is retained in the swirl pot, ensuring that the swirl pot remains
full and maintains a constant supply to the fuel pump.
A four pin electrical connector is located on the top cover of the pump and provides power feed and return for fuel
pump and fuel gauge rotary potentiometer operation. A single quick release coupling connects the fuel feed pipe to
the outer top surface of the pump.
Two metal springs are attached to the top cover and the housing of the pump. When the pump is installed it seats on
the lower surface inside the tank. The springs exert a downward pressure on the pump and ensure that the pump is
located positively at the bottom of the fuel tank.
The fuel pump has a maximum current draw of 6.5 A at 12.5 V.
On NAS vehicles with vacuum type EVAP system leak detection capability only, the fuel pump top cover is fitted with
an On Board Diagnostics (OBD) pressure sensor. This sensor has a three pin electrical connector which provides a
connection between the sensor and the ECM. The sensor is sealed in the top cover with an 'O' ring and secured with
a clip. The sensor monitors tank pressure during OBD tests of the fuel evaporation system integrity. A hose is
connected to the sensor and is routed across the top of the fuel tank and terminates at the top of the fuel filler tube.
The pipe is open to atmosphere and provides atmospheric pressure for the sensor operation.

+ ENGINE MANAGEMENT SYSTEM - V8, DESCRIPTION AND OPERATION, Description - engine
management.

FUEL DELIVERY SYSTEM - V8
19-2-8 DESCRIPTION AND OPERATION
Fuel pressure regulator
The fuel pressure regulator is located in the underside of the top cover. The regulator is sealed with two 'O' rings and
retained with a clip.
The regulator is connected to the fuel feed pipe at the top of the pump housing and maintains the fuel pump delivery
pressure to 3.5 bar (50 lbf.in
2). When the fuel delivery pressure exceeds 3.5 bar (50 lbf.in2), the regulator opens and
relieves excess pressure back to the swirl pot via a return pipe. The regulator ensures that the fuel rails and injectors
are supplied with a constant pressure.
The fuel pump delivery pressure and pressure regulator operating pressure can be checked using a Schraeder type
valve located at the rear of the engine on the fuel rail. The valve allows the pump delivery pressure to be measured
using a suitable gauge and an adaptor and hose which are special tools.
Fuel gauge sender
The fuel gauge sender unit comprises a rotary potentiometer operated by a float. The float rises and falls with the fuel
level in the tank and moves the potentiometer accordingly.
Battery voltage is supplied to the potentiometer. The output voltage from the potentiometer varies according to the
resistance through the potentiometer in relation to the fuel level. The output voltage is connected to the fuel gauge in
the instrument pack. The fuel gauge receives a battery voltage input and this is compared with the output voltage from
the potentiometer. The difference between the two voltages determines the deflection of the fuel gauge pointer.
Fuel gauge reading Tank volume litres (US Gallons) * Sender unit resistance
ohms Ω
FULL 95 (25) 15
3/4 71 (18.8) 36
1/2 48 (12.7) 64
1/4 24 (6.4) 110
RESERVE (fuel light ON) 11 (2.9) 158
EMPTY 0 (0) 245
*Tank volumes are approximate.

COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-5
Description
General
The cooling system used on the Diesel engine is a pressure relief by-pass type system which allows coolant to
circulate around the engine block and heater circuit when the thermostat is closed. With coolant not passing through
the by-pass or the radiator promotes faster heater warm-up which in turn improves passenger comfort.
A coolant pump is mounted on a casting behind the PAS pump and is driven from the PAS pump at crankshaft speed
by the auxiliary drive belt. The pump mounting casting connects with passages in the cylinder block and pumps
coolant from the radiator through the cylinder block.
A viscous fan is attached to an idler pulley at the front of the engine. The fan is attached to a threaded spigot on the
pulley with a left hand threaded nut. The fan draws air through the radiator to assist in cooling when the vehicle is
stationary. The fan rotational speed is controlled relative to the running temperature of the engine by a thermostatic
valve regulated by a bi-metallic coil.
The cooling system uses a 50/50 mix of anti-freeze and water.
A Fuel Burning Heater (FBH) is available as an optional item for Diesel engine variants. The FBH is located on the
bulkhead and is connected in series in the coolant supply to the heater. The FBH is used to compensate for the
relatively low coolant temperatures inherent in the Diesel engine.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.
Thermostat housing
A plastic thermostat housing is located behind the radiator. The housing has three connections which locate the
radiator bottom hose, top hose and coolant pump feed pipe. The housing contains a wax element thermostat and a
spring loaded by-pass flow valve.
Thermostat - Main valve
The thermostat is used to maintain the coolant at the optimum temperature for efficient combustion and to aid engine
warm-up. The thermostat is closed at temperatures below approximately 82
°C (179°F). When the coolant
temperature reaches approximately 82
°C the thermostat starts to open and is fully open at approximately 96°C
(204
°F). In this condition the full flow of coolant is directed through the radiator.
The thermostat is exposed to 90% hot coolant from the engine on one side and 10% cold coolant returning from the
radiator bottom hose on the other side.
Hot coolant from the engine passes from the by-pass pipe through four sensing holes in the flow valve into a tube
surrounding 90% of the thermostat sensitive area. Cold coolant returning from the radiator, cooled by the ambient air,
conducts through 10% of the thermostat sensitive area.
In cold ambient temperatures, the engine temperature is raised approximately 10
°C (50°F) to compensate for the heat
loss of 10% exposure to the cold coolant returning from the radiator bottom hose.
By-pass flow valve
The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm-up. When the main valve
is closed and the engine speed is below 1500 rev/min, the coolant pump does not produce sufficient flow and pressure
to open the valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the
coolant through the heater matrix only. This provides a higher flow of warm coolant through the heater matrix to
improve passenger comfort in cold conditions.
When the engine speed increases above 1500 rev/min the coolant pump produces a greater flow and pressure than
the heater circuit can take. The pressure acts on the flow valve and overcomes the valve spring pressure, opening
the valve and limiting the pressure in the heater circuit. The valve modulates to provide maximum coolant flow through
the heater matrix and yet allowing excess coolant to flow into the by-pass circuit to provide the engines cooling needs
at higher engine rev/min.

COOLING SYSTEM - TD5
26-1-6 DESCRIPTION AND OPERATION
Outlet housing
A cast aluminium outlet housing is attached to the cylinder head with three bolts and sealed with a gasket. Coolant
leaves the engine through the outlet housing and is directed through a hose to the heater matrix, the radiator or the
by-pass circuit.
An Engine Coolant Temperature (ECT) sensor is installed in a threaded port on the side of the outlet housing. The
sensor monitors coolant temperature emerging from the engine and sends signals to the Engine Control Module
(ECM) for engine management and temperature gauge operation.

+ ENGINE MANAGEMENT SYSTEM - Td5, DESCRIPTION AND OPERATION, Description.
Expansion tank
The expansion tank is located in the engine compartment. The tank is made from moulded plastic and attached to
brackets on the right hand inner wing. A maximum coolant when cold level is moulded onto the tank.
Excess coolant created by heat expansion is returned to the expansion tank from the radiator bleed pipe at the top of
the radiator. An outlet pipe is connected into the coolant pump feed hose and replaces the coolant displaced by heat
expansion into the system when the engine is cool.
The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow
excessive pressure and coolant to vent through the overflow pipe. The relief valve is open at a pressure of 1.4 bar (20
lbf.in
2) and above.
Heater matrix
The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the
bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead
are connected to the matrix, sealed with 'O' rings and clamped with circular rings.
The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located
between the tubes and conduct heat from the hot coolant flowing through the tubes. Air from the heater assembly is
warmed as it passes through the matrix fins. The warm air is then distributed in to the passenger compartment as
required.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.
When the engine is running, coolant from the engine is constantly circulated through the heater matrix.
Radiator
The 44 row radiator is located at the front of the vehicle in the engine compartment. The cross flow type radiator is
manufactured from aluminium with moulded plastic end tanks interconnected with tubes. The bottom four rows are
separate from the upper radiator and form the lower radiator for the fuel cooler. Aluminium fins are located between
the tubes and conduct heat from the hot coolant flowing through the tubes, reducing the coolant temperature as it
flows through the radiator. Air intake from the front of the vehicle when moving carries the heat away from the fins.
When the vehicle is stationary, the viscous fan draws air through the radiator fins to prevent the engine from
overheating.
Two connections at the top of the radiator provide for the attachment of the top hose from the outlet housing and bleed
pipe to the expansion tank. Three connections at the bottom of the radiator allow for the attachment of the bottom
hose to the thermostat housing and the return hose from the oil cooler and the feed hose to the fuel cooler.
The bottom four rows of the lower radiator are dedicated to the fuel cooler. The upper of the two connections at the
bottom of the radiator receives coolant from the oil cooler. This is fed through the four rows of the lower radiator in a
dual pass and emerges at the lower connection. The dual pass lowers the coolant temperature by up to 24
°C before
being passed to the fuel cooler.
Two smaller radiators are located in front of the cooling radiator. The upper radiator is the intercooler for the air intake
system and the lower radiator provides cooling of the gearbox oil.

+ EMISSION CONTROL - Td5, DESCRIPTION AND OPERATION, Emission Control Systems.

+ MANUAL GEARBOX - R380, DESCRIPTION AND OPERATION, Description.

+ AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.

BODY CONTROL UNIT
86-3-8 DESCRIPTION AND OPERATION
C0664 connector pin details
IDM inputs
The IDM inputs are communicated to the BCU using the serial datalink so that the BCU can perform the necessary
logic operations:
The V
in for IDM digital signals are defined as follows:
lLogic 1 when V
in ≥ 8V.
lLogic 0 when V
in ≤ 2V.
IDM input voltages between 2 and 8 volts are indeterminate and cannot be guaranteed.
Pin No. Description Input/Output
1 Front left window down Output
2 Front right window down Output
3 Fuel flap release Output
4 Front left window up Output
5Earth-
6 Front right window up Output
7 Battery power supply Input
Description Signal type System
Inertia switch Digital Locking/ Unlocking/ Alarm
Side lamps Digital Exterior lighting
Headlamp dipped beam Digital Exterior lighting
Headlamp main beam daylight running lamps Analogue Exterior lighting
RH direction indicators current sense Analogue Direction indicators/ Hazards/ Alarm
LH direction indicators current sense Analogue Direction indicators/ Hazards/ Alarm
Front wiper park sense Digital Wipers and washers