2002 LAND ROVER DISCOVERY turbo

ENGINE - TD5
REPAIRS 12-1-65
7.Remove 3 bolts securing centrifuge to engine
oil cooler.
8.Remove centrifuge and discard 'O' ring.
9.Remove 2 bolts, remove drain pipe from
centrifuge and discard gasket. Refit
1.Clean mating faces of centrifuge, oil cooler and
sump.
2.Position new gasket and fit oil drain pipe to
centrifuge, tighten bolts to 10 Nm (7 lbf.ft).
CAUTION: Gasket must be fitted dry.
3.Position new 'O' ring to oil cooler.
4.Position centrifuge to oil cooler housing and
tighten bolts to 25 Nm (18 lbf.ft).
5.Using a new gasket, align the centrifuge oil
drain pipe to sump and tighten bolts to 10 Nm
(7 lbf.ft).
CAUTION: Gasket must be fitted dry.
6. Models with air conditioning: Position A/C
compressor and tighten bolts to 25 Nm (18
lbf.ft).
7.Fit turbocharger.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Turbocharger.
8. Models with air conditioning: Fit auxiliary
drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
9.Fit underbelly panel and secure with fixings.
10.Remove stand(s) and lower vehicle.

ENGINE - TD5
12-1-70 OVERHAUL
Gasket - exhaust manifold
$% 30.15.12.01
Disassembly
Note: The following procedure covers engines
fitted with or without an EGR cooler. The EGR
cooler is bolted to the front of the cylinder head.
EU3 engine illustrated
1.Remove 3 bolts securing heater pipe to
cylinder head and turbocharger heat shield.
2.Remove heater pipe.
3.Remove bolt and remove turbocharger heat
shield.
4.Remove and discard 2 Allen screws securing
EGR pipe to exhaust manifold.
5.Remove banjo bolt securing oil feed pipe to
turbocharger and discard sealing washers.
6.Loosen turbocharger drain hose union at
cylinder block.
7.Remove 10 nuts and remove exhaust manifold
and turbocharger.
8.Remove manifold gasket.
Reassembly
1.Clean exhaust manifold mating faces.
2.Position exhaust manifold to cylinder head
using new gasket and fit manifold nuts.
Working from the centre outwards, fit and
tighten nuts to 25 Nm (18 lbf.ft).
3.Clean turbocharger drain and feed hose
unions. 4.Fit turbocharger oil drain hose to cylinder block
and tighten union to 48 Nm (35 lbf.ft) .
5.Fit new sealing washers to turbocharger oil
feed pipe, fit banjo bolt and tighten to 25 Nm
(18 lbf.ft).
6.Position EGR pipe to exhaust manifold. Fit new
Allen screws and tighten to 10 Nm (7 lbf.ft).
7.Position turbocharger heat shield.
8.Position heater pipe to cylinder head and
tighten bolts to 25 Nm (18 lbf.ft).
9.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolt
to 25 Nm (18 lbf.ft).

EMISSION CONTROL - TD5
17-1-4 DESCRIPTION AND OPERATION
Emission Control Systems
Engine design has evolved in order to minimise the emission of harmful by-products. Emission control systems fitted
to Land Rover vehicles are designed to maintain the emission levels within the legal limits pertaining for the specified
market.
Despite the utilisation of specialised emission control equipment, it is still necessary to ensure that the engine is
correctly maintained and is in good mechanical order, so that it operates at its optimum condition.
In addition to emissions improvements through engine design and the application of electronic engine management
systems, special emission control systems are used to limit the pollutant levels developed under certain conditions.
Two main types of additional emission control system are utilised with the Td5 engine to reduce the levels of harmful
emissions released into the atmosphere. These are as follows:
1Crankcase emission control – also known as blow-by gas emissions from the engine crankcase.
2Exhaust gas recirculation – to reduce NO
2 emissions.
Crankcase emission control
All internal combustion engines generate oil vapour and smoke in the crankcase as a result of high crankcase
temperatures and piston ring and valve stem blow-by, a closed crankcase ventilation system is used to vent
crankcase gases back to the air induction system and so reduce the emission of hydrocarbons.
Gases from the crankcase are drawn into the inlet manifold to be burnt in the combustion chambers with the fresh air/
fuel mixture. The system provides effective emission control under all engine operating conditions.
Crankcase gases are drawn through the breather port in the top of the camshaft cover and routed through the breather
hose and breather valve on the flexible air intake duct to be drawn into the turbocharger intake for delivery to the air
inlet manifold via an intercooler.
An oil separator plate is included in the camshaft cover which removes the heavy particles of oil before the crankcase
gas leaves via the camshaft cover port. The rocker cover features circular chambers which promote swirl in the oil
mist emanating from the cylinder head and camshaft carrier. As the mist passes through the series of chambers
between the rocker cover and oil separator plate, oil particles are thrown against the separator walls where they
condense and fall back into the cylinder head via two air inlet holes located at each end of the rocker cover.
The breather valve is a depression limiting valve which progressively closes as engine speed increases, thereby
limiting the depression in the crankcase. The valve is of moulded plastic construction and has a port on the underside
which plugs into a port in the flexible air intake duct. A port on the side of the breather valve connects to the camshaft
cover port by means of a breather hose which is constructed from a heavy-duty braided rubber hose which is held in
place by hose clips. A corrugated plastic sleeve is used to give further protection to the breather hose. The breather
valve is orientation sensitive, and “TOP” is marked on the upper surface to ensure it is mounted correctly.
It is important that the system is airtight so hose connections to ports should be checked and the condition of the
breather hose should be periodically inspected to ensure it is in good condition.

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-3
Engine management component
location - engine compartment
LHD illustrated
1Ambient air pressure sensor
2Engine coolant temperature sensor
3Glow plugs
4Engine Control Module (ECM)
5Fuel pump relay
6Main relay
7A/C clutch and cooling fan relays
8Manifold absolute pressure/ inlet air
temperature sensor9Electronic vacuum regulator solenoid
10Fuel temperature sensor
11Crankshaft speed and position sensor
12Electronic unit injectors
13Turbocharger wastegate modulator
14Mass air flow sensor
15Clutch switch

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-5
1Mass air flow sensor
2Ambient air pressure sensor
3Manifold absolute pressure/ inlet air
temperature sensor
4Engine coolant temperature sensor
5Crankshaft speed and position sensor
6Throttle position sensor
7Fuel temperature sensor
8Brake pedal switch
9Clutch switch
10High/ Low ratio switch
11Main relay
12Malfunction indicator lamp
13Fuel pump relay
14Glow plug warning lamp
15Glow plugs16Electronic unit injectors
17Turbocharger wastegate modulator
18EGR modulator
19Diagnostic connector
20Engine control module
21Cruise control master switch
22Cruise control SET+ switch
23Cruise control RES switch
24Air conditioning clutch relay
25Air conditioning cooling fan relay
26Electronic automatic transmission ECU
27Self levelling and anti-lock brakes ECU
28Instrument cluster
29Body control unit

ENGINE MANAGEMENT SYSTEM - TD5
18-1-6 DESCRIPTION AND OPERATION
Description
General
An engine control module (ECM) controls the five-cylinder direct injection diesel engine, and works on the drive by
wire principle. This means there is no throttle cable, the ECM controls the drivers needs via a signal from the Throttle
Position (TP) sensor on the throttle pedal.
The ECM is a full authoritative diesel specific microprocessor that also incorporates features for cruise control and air
conditioning control. In addition, the ECM supplies output control for the exhaust gas recirculation and turbocharger
boost pressure. The ECM has a self-diagnostic function, which is able to provide backup strategies for most sensor
failures.
The ECM processes information from the following input sources:
lMass air flow sensor.
lAmbient air pressure sensor.
lManifold absolute pressure/inlet air temperature sensor.
lEngine coolant temperature sensor.
lCrankshaft speed and position sensor.
lThrottle position sensor.
lFuel temperature sensor.
lAir conditioning request.
lAir conditioning fan request.
lBrake pedal switch.
lClutch switch.
lCruise control master switch.
lCruise control SET+ switch.
lCruise control RES switch.
lHigh/low ratio switch.
The input from the sensors constantly updates the ECM with the current operating condition of the engine. Once the
ECM has compared current information with stored information within its memory, it can make any adjustment it
requires to the operation of the engine via the following:
lAir conditioning clutch relay.
lAir conditioning cooling fan relay.
lElectronic vacuum regulator solenoid.
lMalfunction indicator lamp.
lFuel pump relay.
lGlow plug warning lamp.
lGlow plugs.
lFuel injectors.
lMain relay.
lTurbocharger wastegate modulator.
lTemperature gauge.
The ECM interfaces with the following:
lElectronic Automatic Transmission (EAT).
lSelf Levelling and Anti-lock Brakes System (SLABS).
lSerial communication link.
lInstrument cluster.
lBody Control Unit (BCU).

ENGINE MANAGEMENT SYSTEM - TD5
18-1-8 DESCRIPTION AND OPERATION
Input/Output
ECM inputs and outputs are detailed below:
Connector C0158
Pin No. Input/Output Function Signal type Value Interfaces
A1 Output Injector 5 Analogue 0
A2 Not used
A3 Output EGR modulator Digital 0-12
A4 Not used
A5 Input FT sensor earth 0 volts 0
A6 Input MAP sensor Analogue 0-5 volts
A7 Input ECT sensor Analogue 0-5 volts
A8 Sensor supply Sensor supply 5 volts 5 volts
A9 HT pin
A10 Input AAP sensor Analogue 0-5 volts
A11 Input MAF sensor Analogue 0-5 volts
A12 Not used
A13 Input CKP sensor positive Analogue
A14 Not used
A15 Input Sensor earth 5 0 volts 0 volts
A16 Input CKP sensor screened earth 0 volts 0 volts
A17 Input Sensor earth 6 0 volts 0 volts
A18 Input Sensor earth 3 0 volts 0 volts
A19 Input FT sensor Analogue 0-5 volts
A20 Input Sensor earth 2 0 volts 0 volts
A21 Output Turbocharger wastegate
modulatorDigital 0-12 volts
A22 Output Injector common 2 Analogue 0-85 volts
A23 Output Injector common 1 Analogue 0-85 volts
A24 Output Injector 4 Analogue 0 volts
A25 Output Injector 1 Analogue 0 volts
A26 Output Injector 2 Analogue 0 volts
A27 Output Injector 3 Analogue 0 volts
A28 Not used
A29 Output Glow plug relay Analogue 0-90 volts
A30 Input Sensor earth 4 0 volts 0 volts
A31 Not used
A32 Input/Output CAN negative Digital 2.5-5 volts EAT
A33 Input High/low ratio switch Digital 0-5 volts EAT, SLABS
A34 Input IAT sensor Analogue 0-5 volts
A35 Input/Output Can positive Digital 2.5-5 volts EAT
A36 Input CKP sensor negative 0 volts 0 volts

ENGINE MANAGEMENT SYSTEM - TD5
18-1-10 DESCRIPTION AND OPERATION
Mass Air Flow (MAF) sensor
The MAF sensor is located in the intake system between the air filter housing and the turbocharger. The ECM uses
the information generated by the MAF to control exhaust gas recirculation (EGR).
The MAF sensor works on the hot film principal. The MAF sensor has 2 sensing elements contained within a film. One
element is controlled at ambient temperature e.g. 25
°C (77 °F) while the other is heated to 200 °C (392 °F) above
this temperature e.g. 225
°C (437 °F). As air passes through the MAF sensor the hot film will be cooled. The current
required to keep the constant 200
°C (392 °F) difference provides a precise although non-linear signal of the air drawn
into the engine. The MAF sensor sends a voltage between 0 and 5 volts to the ECM proportional to the mass of the
incoming air. This calculation allows the ECM to set the EGR ratio for varying operating conditions.
Input/Output
The MAF sensor receives battery voltage from the main relay in the engine compartment fuse box. Signal output from
the MAF sensor to the ECM is a variable voltage proportional to air drawn into the engine.
Input to the MAF sensor is via pin 5 of connector C0570 at the engine compartment fuse box. This 12 volt supply is
provided by the main relay via fuse 2 in the engine compartment fuse box. The MAF sensor receives the input voltage
at pin 3 of the sensor connector.
Output from the MAF sensor is measured at pin 11 of the ECM connector C0158. The earth path is via pin 20 of the
ECM connector C0158.
The MAF sensor can fail the following ways or supply incorrect signal:
lSensor open circuit.
lShort circuit to vehicle supply.
lShort circuit to vehicle earth.
lContaminated sensor element.
lDamaged sensor element.
lDamaged in wiring harness.
lMAF supplies incorrect signal (due to air leak or air inlet restriction).
In the event of a MAF sensor signal failure any of the following symptoms may be observed:
lDuring driving engine speed may dip, before recovering.
lDifficult starting.
lEngine stalls after starting.
lDelayed throttle response.
lEGR inoperative.
lReduced engine performance.
lMAF signal out of parameters.
The MIL will not illuminate in a MAF sensor failure, and the ECM will use a fixed default value from its memory.