2002 LAND ROVER DISCOVERY coolant

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-53
Function
The CAN system uses a twisted pair of wires to form the 'data bus' to minimise electrical interference. This method of
serial interface is very reliable and very fast. The information messages are structured so that each of the receivers
(ECM or EAT ECU) is able to interpret and react to the messages sent.
The CAN 'data bus' is directly connected between pin 36 of connector C0637 of the ECM and pin 16 of connector
C0193 at the EAT ECU, and pin 37 of connector C0637 of the ECM and pin 44 of connector C0193 at the EAT ECU.
The CAN system can fail in the following ways:
lCAN data bus wiring open circuit.
lCAN data bus wiring short circuit.
In the event of a CAN data bus failure any of the following symptoms may be observed:
lMIL illuminated after 2 drive cycles (NAS only).
lEAT defaults to 3rd gear only.
lHarsh gearshifts.
l'Sport' and 'manual' lights flash alternately.
Should a malfunction of the component occur the following fault codes may be evident and can be retrieved by
TestBook.
Drive cycles
The following are the TestBook drive cycles:

Drive cycle A:
1Switch on the ignition for 30 seconds.
2Ensure engine coolant temperature is less than 60
°C (140°F).
3Start the engine and allow to idle for 2 minutes.
4Connect TestBook and check for fault codes.

Drive cycle B:
1Switch ignition on for 30 seconds.
2Ensure engine coolant temperature is less than 60
°C (140°F).
3Start the engine and allow to idle for 2 minutes.
4Perform 2 light accelerations (0 to 35 mph (0 to 60 km/h) with light pedal pressure).
5Perform 2 medium accelerations (0 to 45 mph (0 to 70 km/h) with moderate pedal pressure).
6Perform 2 hard accelerations (0 to 55 mph (0 to 90 km/h) with heavy pedal pressure).
7Allow engine to idle for 2 minutes.
8Connect TestBook and with the engine still running, check for fault codes.
P Code J2012 Description Land Rover Description
P0600 Serial communication link malfunction CAN time out
P1776 Transmission control system torque interface
malfunctionEAT torque interface error

ENGINE MANAGEMENT SYSTEM - V8
18-2-54 DESCRIPTION AND OPERATION

Drive cycle C:
1Switch ignition on for 30 seconds.
2Ensure engine coolant temperature is less than 60
°C (140°F).
3Start the engine and allow to idle for 2 minutes.
4Perform 2 light accelerations (0 to 35 mph (0 to 60 km/h) with light pedal pressure).
5Perform 2 medium accelerations (0 to 45 mph (0 to 70 km/h) with moderate pedal pressure).
6Perform 2 hard accelerations (0 to 55 mph (0 to 90 km/h) with heavy pedal pressure).
7Cruise at 60 mph (100 km/h) for 8 minutes.
8Cruise at 50 mph (80 km/h) for 3 minutes.
9Allow engine to idle for 3 minutes.
10Connect TestBook and with the engine still running, check for fault codes.
NOTE: The following areas have an associated readiness test which must be flagged as complete, before a problem
resolution can be verified:
lcatalytic converter fault;
lEvaporative loss system fault;
lHO
2 sensor fault;
lHO
2 sensor heater fault.
When carrying out a drive cycle C to determine a fault in any of the above areas, select the readiness test icon to
verify that the test has been flagged as complete.

Drive cycle D:
1Switch ignition on for 30 seconds.
2Ensure engine coolant temperature is less than 35
°C (95°F).
3Start the engine and allow to idle for 2 minutes.
4Perform 2 light accelerations (0 to 35 mph (0 to 60 km/h) with light pedal pressure).
5Perform 2 medium accelerations (0 to 45 mph (0 to 70 km/h) with moderate pedal pressure).
6Perform 2 hard accelerations (0 to 55 mph (0 to 90 km/h) with heavy pedal pressure).
7Cruise at 60 mph (100 km/h) for 5 minutes.
8Cruise at 50 mph (80 km/h) for 5 minutes.
9Cruise at 35 mph (60 km/h) for 5 minutes.
10Allow engine to idle for 2 minutes.
11Connect TestBook and check for fault codes.

Drive cycle E:
1Ensure fuel tank is at least a quarter full.
2Carry out Drive Cycle A.
3Switch off ignition.
4Leave vehicle undisturbed for 20 minutes.
5Switch on ignition.
6Connect TestBook and check for fault codes.

ENGINE MANAGEMENT SYSTEM - V8
REPAIRS 18-2-73
5.Remove 2 nuts and release ECM from studs
and location on 'A' post lower panel.
6.Lower ECM into footwell and disconnect 5
multiplugs.
7.Remove ECM.
Refit
1.Position new ECM and connect multiplugs.
2.Fit ECM and secure with nuts.
3.Fit lower trim panel to 'A' post and secure with
fixings.
4.Fit diagnostic socket to closing panel, fit closing
panel and secure with fixings.
5.Connect battery earth lead.
6.Fit battery cover and secure with fixings.
7.Programme ECM and reset adaptions using
TestBook.
Sensor - engine coolant temperature
(ECT)
$% 18.30.10
Remove
1.Release turnbuckles and remove battery cover.
2.Disconnect battery earth lead.
3.Remove auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
4.Remove 2 bolts securing alternator, release
alternator from support bracket and position
aside.

ENGINE MANAGEMENT SYSTEM - V8
REPAIRS 18-2-75
4.Fit CKP sensor heat shield and secure with
bolts.
5.Fit underbelly panel and secure with fixings.
6.Remove stand(s) and lower vehicle.
7.Connect battery earth lead.
8.Fit battery cover and secure the fixings.
9.Reset adaptions using TestBook.
Sensor - radiator temperature
$% 18.30.20
Remove
1.Disconnect battery earth lead.
2.Position container to collect coolant spillage.
3.Disconnect multiplug from sensor.
4.Remove sensor and discard sealing washer.
Refit
1.Fit new sealing washer to sensor.
2.Fit and tighten sensor.
3.Connect multiplug to sensor.
4.Refill cooling system.
5.Connect battery earth lead.

ENGINE MANAGEMENT SYSTEM - V8
18-2-80 REPAIRS
Throttle Body
$% 19.22.45
Remove
1.Loosen 3 clips securing air intake hose, release
air intake hose and position aside.
Note: Pre 03 MY air intake hose illustrated.
2.Disconnect throttle and cruise control cables
from throttle body. 3.Loosen clip securing breather hose and release
hose.
4.Disconnect multiplug from throttle body.
5.Position a container below the throttle body to
collect coolant spillage.
6.Loosen 2 clips securing coolant hoses to
throttle body and release hoses.
7.Remove 4 bolts securing throttle body to
plenum chamber.
8.Remove throttle body and discard gasket.
Refit
1.Clean plenum chamber and throttle body
mating faces.
2.Using a new gasket, position throttle body, fit
bolts and tighten to 9 Nm (7 lbf.ft).
3.Connect coolant hoses to throttle body and
secure clips.
4.Connect breather hose to throttle body and
secure clip.
M19 2576A
1

COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-3
1Pressure cap
2Overflow pipe
3Heater return hose
4Heater matrix
5Heater inlet hose
6Oil cooler return pipe — EU3 models
7Connecting hose
8Oil cooler housing assembly
9Heater inlet pipe
10Connecting hose
11Outlet housing
12Engine Coolant Temperature (ECT) sensor
13Bleed screw
14Radiator top hose
15Radiator - upper
16Intercooler
17Gearbox oil cooler
18Radiator - lower
19Viscous fan
20Drain plug21Connecting hose
22Fuel cooler feed hose
23Radiator bottom hose
24Thermostat housing
25Connecting hose
26Coolant pump feed pipe
27Coolant by-pass pipe
28Radiator bleed pipe
29Connecting hose
30Coolant pump
31Fuel cooler
32Heater/expansion tank return hose
33Expansion tank
34EGR Cooler - EU3 models
35Connecting hose - EU3 models
36Connecting hose - EU3 models
37Hose - EGR Cooler to oil cooler return pipe -
EU3 models
38Radiator lower feed hose - Pre EU3 models
39Oil cooler return pipe - Pre EU3 models

COOLING SYSTEM - TD5
26-1-4 DESCRIPTION AND OPERATION
Cooling system coolant flow
Coolant flow diagram
aEU 3 Models
bPre EU3 Models

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.