2002 LAND ROVER DISCOVERY ECU

ENGINE MANAGEMENT SYSTEM - TD5
18-1-60 REPAIRS
11.Remove fuel temperature sensor and discard
sealing washer.
12.Remove fuel hose and fuel pipe and discard 'O'
rings.
Refit
1.Clean fuel pressure regulator and mating face.
2.Clean fuel pipe unions.
3.Using new 'O' rings, fit fuel pipe and fuel hose
to pressure regulator and tighten unions to 25
Nm (18 lbf.ft).
4.Using new sealing washer, fit fuel temperature
sensor and tighten to 14 Nm (10 lbf.ft).
5.Fit new fuel filter and 'O' ring.
6.Using a new gasket, position pressure
regulator and tighten bolts to 25 Nm (18 lbf.ft).
7.Connect multiplug to fuel temperature sensor.
8.Connect fuel hoses to pressure regulator and
fuel cooler.
9.Fit engine lifting eye and tighten bolts to 25 Nm
(18 lbf.ft).
10.Fit engine acoustic cover and tighten bolts to 10
Nm (6 lbf.ft).
11.Connect battery earth lead.
12.Fit battery cover and secure fixings.
Glow plugs
$% 19.60.31
Remove
1.Remove 3 bolts and remove engine acoustic
cover.
2.Release turnbuckles and remove battery cover.
3.Disconnect battery earth lead.
4.Disconnect 4 glow plug leads.
5.Loosen and remove 4 glow plugs.
Refit
1.Thoroughly clean glow plugs and seating area
in cylinder head.
2.Apply a suitable anti-sieze compound to
threads of glow plugs.
3.Fit glow plugs and tighten to 16 Nm (12 lbf. ft).
4.Connect glow plug leads.
5.Fit engine acoustic cover and secure fixings.
6.Connect battery earth lead.
7.Fit battery cover and secure fixings.

ENGINE MANAGEMENT SYSTEM - TD5
REPAIRS 18-1-61
Injectors
$% 19.60.12
Remove
1.Remove cooling fan.

+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
2.Remove rocker shaft.

+ ENGINE - Td5, REPAIRS, Rocker
shaft assembly.
3.Position container to catch fuel spillage.
4.Disconnect quick release fuel hose connectors
from fuel connector block on cylinder head and
fuel cooler to drain fuel from cylinder head. 5.Disconnect 5 multiplugs from injectors.
6.Remove 5 Torx bolts securing injectors to
cylinder head.
7.Using LRT-12-154/1, remove injectors from
cylinder head. Collect retainers.
8.Using LRT-12-154/4, remove sealing washers
from injectors. Discard sealing washers.
9.Remove and discard 'O' rings from injectors.
10.Rotate engine manually until each cylinder
being worked on is at TDC, and remove excess
fuel from piston bowl using a syringe.

ENGINE MANAGEMENT SYSTEM - TD5
REPAIRS 18-1-63
Switch - cruise control (set/resume)
$% 19.75.33
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.
3.Release remote control switches multiplug and
leads from steering wheel base.
4.Disconnect remote control switches multiplug
from harness.
5.Remove 2 screws securing remote control
switches to steering wheel base.
6.Release and remove remote control switches
from steering wheel.
Refit
1.Fit remote control switches to steering wheel
and secure with screws.
2.Connect remote control switches multiplug to
harness.
3.Secure leads and multiplug to base of steering
wheel.
4.Fit driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.
Switch - clutch
$% 19.75.34
Remove
1.Disconnect the multiplug from the clutch switch.
2.Position a container below the clutch switch to
collect the fluid.
3.Unscrew and remove the clutch switch.
CAUTION: Always fit plugs to open
connections to prevent contamination.
Refit
1.Fit the clutch switch and tighten to 10 Nm (7
lbf.ft).
2.Connect the multiplug.
3.Bleed the clutch hydraulic system.

+ CLUTCH - Td5, ADJUSTMENTS,
Clutch hydraulic system - bleed.

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-5
1Engine control module
2Crankshaft speed and position sensor
3Camshaft position sensor
4Engine coolant temperature sensor
5Mass air flow/ inlet air temperature sensor
6Throttle position sensor
7Heated oxygen sensors
8Fuel injectors
9Idle air control valve
10Fuel pump relay
11EVAP canister
12EVAP canister vent valve
13EVAP canister purge valve
14Fuel tank pressure sensor
15Ignition coils
16Knock sensor
17Spark plugs
18High/ Low ratio switch
19Malfunction indication lamp
20Diagnostic connector
21Air temperature control clutch relay
22Air temperature control cooling fan relay
23ATC ECU
24CAN link to EAT
25SLABS ECU
26BCU
27Instrument cluster
28Thermostat monitoring sensor (where fitted)

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-7
The ECM controls the following outputs:
lFuel injectors (1 per cylinder).
lIgnition coils/ high tension leads/ spark plugs.
lFuel pump relay.
lIdle air control valve.
lHeated oxygen sensors.
lEVAP canister purge valve.
lEVAP canister vent solenoid (CVS) valve (where fitted).
lMalfunction Indicator Lamp (MIL)/ service engine soon lamp (where fitted).
lHill descent control (via SLABS interface).
lEVAP system fuel leak detection pump (where fitted)
lSecondary air injection pump (where fitted)
The ECM also interfaces with the following:
lDiagnostics via diagnostic connector with TestBook.
lController Area Network (CAN) link to EAT ECU.
lAir conditioning system.
lSelf Levelling & Anti-lock Braking System (SLABS) ECU.
lImmobilisation system via the body control unit (BCU).
lInstrument cluster.
lCruise control ECU
lActive Cornering Enhancement (ACE) ECU
Engine Control Module (ECM)
The engine control module (ECM) is located on the RH side A post below the face panel inside the vehicle. It has a
cast aluminium case and is mounted on a bracket. The ECM has 5 independent connectors totalling 134 pins.
The ECM is available in 4 variants:
lNAS.
lNAS low emission vehicles.
lUK/ Europe/ Japan/ Australia.
lROW/ Gulf.
The ECM uses a 'flash' electronic erasable programmable read only memory (EEPROM). This enables the ECM to
be externally configured, to ensure that the ECM can be updated with any new information, this also allows the ECM
to be configured with market specific data. TestBook must be used to configure replacement ECM's. The ECM can
be reconfigured up to 16 times to meet changing specifications and legislation.
The ECM memorises the positions of the crankshaft and the camshaft when the engine has stopped via the CKP and
CMP sensors. This allows immediate sequential fuel injection and ignition timing during cranking. This information is
lost if battery voltage is too low (i.e. flat battery). So the facility will be disabled for the first engine start.

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-25
Throttle Position (TP) sensor (C0175)
The TP sensor is located on the throttle body assembly in the engine compartment. The ECM is able to determine the
position of the throttle plate and the rate of change of its angle. The ECM processes the signal received from the TP
sensor.
The TP sensor consists of a resistance track and a sliding contact connected to the throttle plate assembly. As the
throttle is opened and closed the sliding contact moves along the resistance track to change the output voltage of the
sensor. The ECM determines throttle plate position by processing this output voltage. The connection of the sensor
to the throttle plate assembly is via a shaft.
The ECM is able to determine the closed throttle position, this enables the TP sensor to be fitted without the need for
prior adjustment. The TP sensor signal has input into the ECM's fuelling strategy and also to determine closed throttle
position for idle speed control. The TP sensor also supplies the ECM with information to enable the overrun fuel cut
off strategy to be implemented. When the ECM receives closed throttle information from the TP sensor it closes the
injectors for the duration of the closed throttle time.
The TP sensor signal is also used by the Electronic Automatic Transmission (EAT) ECU to determine the correct point
for gear shifts and acceleration kickdown. The ECM also supplies the SLABS ECU with this TP sensor information as
a PWM signal.
Input/Output
The TP sensor has electrical input and output. Input is a 5 volt supply via pin 10 of connector C0636 of the ECM. The
signal output is via pin 24 of connector C0636 and is a varying voltage, less than 0.5V (closed throttle) and greater
than 4.5V (wide open throttle) depending on throttle plate position. The TP sensor earth is via pin 25 of connector
C0636 of the ECM, this acts as a screen to protect the integrity of the TP sensor signal.
The connector and sensor terminals are gold plated for corrosion and temperature resistance, care must be exercised
while probing the connector and sensor terminals.
If the TP sensor signal fails, the ECM uses a default value derived from engine load and speed.
The TP sensor can fail the following ways or supply incorrect signal:
lSensor open circuit.
lShort circuit to vehicle supply.
lShort circuit to vehicle earth.
lSignal out of parameters.
lBlocked air filter (load monitoring, ratio of the TP sensor to air flow).
lRestriction in air inlet (load monitoring, ratio of the TP sensor to air flow).
lVacuum leak

ENGINE MANAGEMENT SYSTEM - V8
18-2-40 DESCRIPTION AND OPERATION
Air Temperature Control (ATC) request
The ATC request comes via the ATC switch located in the facia panel. When the driver operates the switch it acts as
a request from the ATC ECU to engage the ATC clutch to drive the system.
During periods of high driver demand such as hard acceleration or maximum rev/min the ATC clutch will be disabled
for a short time. This is to reduce the load on the engine.

+ AIR CONDITIONING, DESCRIPTION AND OPERATION, Description.
Input/Output
The operation of the ATC request is via a switch being connected to earth. Voltage is supplied via pin 38 of connector
C0637 of the ECM, at the point at when the switch is pressed the connection is made and the ATC clutch is engaged.
The ATC request can fail as follows:
lOpen circuit.
lShort circuit to voltage supply.
lShort circuit to vehicle earth.
lWiring loom fault.
In the event of an ATC request failure, the ATC system does not work.
Should a malfunction of the component occur the following fault codes may be evident and can be retrieved by
TestBook.
ATC compressor clutch relay
The ATC compressor clutch relay is located in the engine compartment fuse box. It is a four pin normally open relay.
The relay must be energised to drive the ATC compressor clutch.
P Code J2012 Description Land Rover Description
P1535 Air conditioning compressor request
malfunctionATC requested when not in standby mode

ENGINE MANAGEMENT SYSTEM - V8
18-2-46 DESCRIPTION AND OPERATION
Idle speed control
The ECM regulates the engine speed at idling. The ECM uses the idle air control valve (IACV) to compensate for the
idle speed drop that occurs when the engine is placed under greater load than usual. When the throttle is in the rest
position i.e. it has not been pressed, the majority of intake air that the engine consumes comes from the idle air control
valve.
IACV control idle speed
Conditions in which the ECM operates the IACV control idle speed is as follows:
lIf any automatic transmission gears other than P or N are selected.
lIf air conditioning is switched on.
lIf cooling fans are switched on.
lAny electrical loads activated by the driver.
Function
The idle air control valve utilises two coils that use opposing pulse width modulated (PWM) signals to control the
position of a rotary valve. If one of the circuits that supplies the PWM signal fails, the ECM closes down the remaining
signal preventing the idle air control valve from working at its maximum/ minimum setting. If this should occur, the idle
air control valve assumes a default idle position at which the engine idle speed is raised to 1200 rev/min with no load
placed on the engine.
Evaporative emission control
Due to increasing legislation, all new vehicles must be able to limit evaporative emissions (fuel vapour) from the fuel
tank.
The ECM controls the emission control system using the following components:
lEVAP canister.
lPurge valve.
lCanister vent solenoid (CVS) valve – (NAS vehicles with vacuum type EVAP system leak detection capability
only)
lFuel tank pressure sensor – (NAS vehicles with vacuum type EVAP system leak detection capability only)
lFuel leak detection pump – (NAS vehicles with positive pressure type EVAP system leak detection capability
only)
lInterconnecting pipe work.
Refer to Emissions section for operating conditions of evaporative emission systems.

+ EMISSION CONTROL - V8, DESCRIPTION AND OPERATION, Evaporative emission control operation.
On-Board Diagnostics (OBD) - North American Specification vehicles only
The ECM monitors performance of the engine for misfires, catalyst efficiency, exhaust leaks and evaporative control
loss. If a fault occurs, the ECM stores the relevant fault code and warns the driver of component failure by illuminating
the Malfunction Indicator Light in the instrument pack.
On vehicles fitted with automatic gearbox, the ECM combines with the Electronic Automatic Transmission (EAT) ECU
to provide the OBD strategy.
Conditions
If the OBD function of the ECM flags a fault during its operation, it falls into one of the following categories:
lmin = minimum value of the signal exceeded.
lmax = maximum value of the signal exceeded.
lsignal = signal not present.
lplaus = an implausible condition has been diagnosed.