cooling system - td5 LAND ROVER DISCOVERY 2002 Owner's Manual

ENGINE - TD5
REPAIRS 12-1-63
Refit
1.Clean oil pressure switch threads.
2.Fit oil pressure switch and tighten to 15 Nm (11
lbf.ft).
3.Connect multiplug to oil pressure switch.
4.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolts
to 25 Nm (18 lbf.ft).
5.Fit and secure engine acoustic cover.
6.Top up engine oil.

+ MAINTENANCE, PROCEDURES,
Engine oil - diesel engine.
Cooler - engine oil
$% 12.60.68
Remove
1.Drain cooling system.

+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
2.Remove centrifuge assembly.

+ ENGINE - Td5, REPAIRS, Gasket -
centrifuge oil drain pipe.
3.Remove clutch housing bolt and release
coolant pipe from rear of engine.
4.Release clip and coolant hose from oil cooler.
5.Disconnect multiplug from oil pressure switch.
6.Remove full-flow oil filter element using a
suitable strap wrench.
7.Remove 3 bolts, remove oil filter adaptor
housing and discard gasket.
8.Remove 7 bolts, remove oil cooler and discard
gasket.
9.Remove oil pressure switch.

ENGINE - TD5
12-1-64 REPAIRS
Refit
1.Clean oil cooler and mating faces.
2.Fit oil pressure switch and tighten to 9 Nm (7
lbf.ft).
3.Position new gasket and fit oil cooler housing,
tighten bolts to 25 Nm (18 lbf.ft).
4.Position and fit oil filter adaptor housing,
tighten bolts to 25 Nm (18 lbf. ft).
5.Fit oil filter, tighten hand tight then a further half
turn.
6.Position coolant hose to oil cooler and secure
clip.
7.Position coolant pipe bolt and tighten to 50 Nm
(37 lbf.ft) .
8.Connect multiplug to oil pressure switch.
9.Fit centrifuge assembly.

+ ENGINE - Td5, REPAIRS, Gasket -
centrifuge oil drain pipe.
10.Refill cooling system.

+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
11.Top up engine oil.

+ MAINTENANCE, PROCEDURES,
Engine oil - diesel engine.
Gasket - centrifuge oil drain pipe
$% 12.60.90
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove fixings and remove underbelly panel.
3.Remove 2 bolts securing centrifuge drain to
engine sump and discard gasket. (Some
models are fitted with studs and nuts,
others with bolts).
4.Remove turbocharger.

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

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
6. Models with air conditioning: Remove 4 bolts
securing compressor and move to one side.

EMISSION CONTROL - TD5
17-1-14 REPAIRS
Valve - EGR - Pre EU3 models
$% 17.45.01
On all vehicles up to VIN number 1A736339, the
EGR pipe assembly must be replaced every time the
system is disturbed.
Remove
1.Release turnbuckles and remove battery cover.
2.Disconnect battery earth lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Remove cooling fan coupling.

+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
5.Disconnect vacuum hose(s) from EGR valve.
6.Loosen clip and release air intake from EGR
valve.
7.Remove 4 bolts, release EGR valve from inlet
manifold and discard gasket.
8.Remove 2 bolts and release EGR valve clip
from cylinder head.
9.Remove and discard 2 bolts securing EGR
valve pipe to exhaust manifold. 10.Remove EGR valve assembly.
11.Remove clip and remove pipe from EGR valve.
Refit
1.Clean EGR valve and mating face on pipe.
2.Position pipe to EGR valve and fit retaining clip.
Fit bolt but do not tighten at this stage.
3.Position EGR valve assembly, locate pipe
flange to exhaust manifold, fit new bolts but do
not tighten at this stage.
4.Clean inlet manifold and EGR valve mating
faces.
5.Using new gasket, position EGR valve to inlet
manifold fit bolts and tighten to 10 Nm (7 lbf.ft).
6.Align EGR pipe clip to cylinder head, fit bolts
but do not tighten at this stage.
7.Tighten EGR pipe bolts to correct torque in
following sequence:
lEGR pipe retaining clip bolt 6 Nm (4.5 lbf.ft)
lEGR pipe clip to cylinder head bolts 10 Nm
(7 lbf.ft)
lEGR pipe flange to exhaust manifold bolts
10 Nm (7 lbf.ft)
8.Position air intake hose and tighten clip.
9.Connect vacuum hoses to EGR valve.
10.Fit cooling fan coupling.

+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
11.Connect battery earth lead.
12.Fit battery cover and secure the fixings.

EMISSION CONTROL - TD5
REPAIRS 17-1-15
Valve - EGR - EU3 models
$% 17.45.01
Remove
1.Release turnbuckles and remove battery cover.
2.Disconnect battery earth lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Remove cooling fan coupling.

+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
5.Disconnect vacuum hose(s) from EGR valve.
6.Loosen clip screw and disconnect air intake
hose from EGR valve.
7.Remove screw and remove clamp securing
EGR pipe to EGR valve.
8.Remove 4 bolts securing EGR valve, remove
valve and discard gasket.
9.Discard EGR pipe gasket.Refit
1.Clean EGR valve and mating faces.
2.Fit new gasket to EGR pipe.
3.Using new gasket, position EGR valve to inlet
manifold fit bolts and tighten to 10 Nm (7 lbf.ft).
4.Fit EGR pipe clamp and tighten screw to 6 Nm
(4.4 lbf.ft).
5.Connect air intake hose to EGR valve and
tighten clip.
6.Connect vacuum hoses to EGR valve.
7.Fit cooling fan coupling.
+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
8.Fit engine acoustic cover and tighten bolts to
10 Nm (7 lbf.ft).
9.Connect battery earth lead.
10.Fit battery cover and secure the fixings.

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
DESCRIPTION AND OPERATION 18-1-9
Connector C0658
Pin No. Input/Output Function Signal type Value Interfaces
B1 Input Earth 1 0 volts 0 volts
B2 Input Earth 4 0 volts 0 volts
B3 Input Supply battery voltage 12 volts 12 volts
B4 Output Cooling fan relay Switch 12-0 volts A/C ECU
B5 Output Fuel pump relay Switch 12-0 volts
B6 Output MIL Switch 12-0 volts Instruments
B7 Output Temperature gauge Digital 0-12 volts Instruments
B8 Not used
B9 Input A/C clutch request Switch 12-0 volts A/C ECU
B10 Input Normally closed brake
switchSwitch 12-0 volts
B11 Input Cruise control SET+ switch Switch 12-0 volts
B12 Input TP sensor 1 Analogue 0- 5 volts
B13 Input Vehicle speed Digital 0-12 volts
B14 Input TP sensor supply 5 volts 5 volts
B15 Input Cruise control master switch Switch 12-0 volts
B16 Input Normally open brake switch Switch 0-12 volts
B17 Input Cruise control RES switch Switch 12-0 volts
B18 Input/Output Serial communication link Digital 0-12 volts All ECU's
B19 Output Tachometer engine speed Digital 0-12 volts Instrument
Cluster
B20 Not used
B21 Output Main relay Switch 0-12 volts
B22 Input Supply battery voltage 12 volts 12 volts
B23 Input A/C fan request Switch 12-0 volts
B24 Input Earth 3 0 volts 0 volt
B25 Input Earth 2 0 volts 0 volts
B26 Input TP sensor earth 0 volts 0 volts
B27 Input Supply 2 12 volts 12 volts
B28 Not used
B29 Output A/C relay Switch 12-0 volts
B30 Output Glow plug warning light Switch 12-0 volts Instrument
Cluster
B31 Not used
B32 Output ABS digital 0-5 volts SLABS
B33 Input Ignition Switch 0-12 volts
B34 Input Security code digital 0-5 volts
B35 Input Clutch switch Switch 12-0 volts
B36 Input TP sensor 2 Analogue 5-0 volts

ENGINE MANAGEMENT SYSTEM - TD5
18-1-14 DESCRIPTION AND OPERATION
Engine Coolant Temperature (ECT) sensor
The ECT sensor is located in the coolant outlet elbow on the top of the engine. It provides the ECM with engine coolant
temperature information. The ECM uses this ECT information for the following functions:
lFuelling calculations.
lTemperature gauge.
lTo limit engine operation if coolant temperature is too high.
lCooling fan operation.
lGlow plug operating time.
The ECT works as an NTC sensor. As temperature rises, the resistance in the sensor decreases, as temperature
decreases, the resistance in the sensor increases. The ECM compares the voltage signal to stored values and
compensates fuel delivery to ensure optimum driveability at all times.
Input/Output
The inputs and outputs for the ECT are earth and signal out.
The ECT signal is measured at pin 7 of the ECM connector C0158. The earth path is via pin 18 of ECM connector
C0158.
ECT sensor temperature to resistance table.
Temperature, °C Temperature, °F Resistance, ohms
nominal)
-10 14 9397
0325896
10 50 3792
30 86 1707
50 122 834.0
70 158 435.7
90 194 243.2
110 230 144.2
130 266 89.3

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-33
The turbocharger is exposed to extremely high operating temperatures (up to 1,000 °C (1832 °F)) because of the hot
exhaust gases and the high speed revolution of the turbine (up to 150,000 rev/min). In order to resist wear of the
turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings cool. Oil
is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo connections.
Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the turbocharger
assembly.
A heatshield is attached to the left hand side of the engine to protect adjacent components from the heat generated
at the turbocharger. The heatshield is attached to the engine by two bolts an additional bolt attaches the heatshield
to the turbocharger casting.
The engine control module controls the amount of boost pressure the engine receives by way of the turbocharger.
When full boost is reached a control signal is sent to the wastegate modulator, and a vacuum is applied to the
wastegate valve. The wastegate valve opens, bypassing some of the exhaust gas away from the turbine to be output
to the exhaust system.
The engine should be allowed to idle for 15 seconds following engine start up and before the engine is switched off
to protect the turbocharger by maintaining oil supply to the turbine bearings.
Intercooler
The intercooler is an air-to-air heat exchanger which lowers the intake air temperature to obtain a higher air density
for better combustion efficiency. The intercooler receives compressed air from the turbocharger via a metal pipe; it
cools the intake air via the intercooler matrix and delivers it to the intake manifold by means of a rubber hose which
connects between the intercooler outlet and the intake manifold outlet. The rubber hose is connected to ports at each
end by metal band clips.

+ COOLING SYSTEM - Td5, DESCRIPTION AND OPERATION, Description.
The intercooler is located at the front of the engine bay, forward of the radiator.