engine LAND ROVER DISCOVERY 1999 Workshop Manual

WIPERS AND WASHERS
DESCRIPTION AND OPERATION 84-13
Rear wiper motor
The DC motor contains two permanent magnets and a park switch. An earth braid attached between the motor casing
and the brush pack is utilised to minimise radio interference during wiper functions.
The rear wiper switch provides an earth signal to the BCU, which determines the delay interval, if appropriate. The
BCU then signals the IDM to activate the rear wiper motor relay, which provides power to the rear wiper motor.
To allow the rear wiper to park when the rear wiper is switched off, power flows through the park switch until a cam
in the wiper motor assembly breaks the contact of the park switch. Triggering the park switch grounds the positive
side of the wiper motor causing it to stop abruptly
Washers
The washer system comprises a reservoir, washer pumps, hoses and washer jets. The front washers are controlled
from a stalk switch on the steering column and the rear washers are operated by a non-latching pushbutton switch on
the fascia adjacent to the instrument pack.
Reservoir
The reservoir is located behind the front bumper in the inner wheel arch and has a capacity of 6.0 litres (12.5 US pints).
A filler neck tube is connected to the reservoir with a seal and extends into the engine compartment on the front left
hand side. The filler neck tube contains a removable filter to prevent particle contamination and a yellow float to show
reservoir contents. The washer filler neck tube is sealed with a cap which is coloured blue for identification.
Two electric washer pumps are located on the rear face of the reservoir and supply washer fluid to the front
windscreen and the tail door window. Each pump is sealed to the reservoir with a rubber sealing grommet.
On vehicles with headlamp powerwash fitted, a third pump is fitted with a sealing grommet to the front face of the
reservoir.
The reservoir and filler neck tube are manufactured from moulded opaque nylon. The reservoir has moulded lugs for
attachment to the vehicle body. A bracket is attached to the top of the filler neck tube and locates in a hole in the body
to secure the top of the tube.
Front screen washer jets
Two washer jets for the front windscreen are fitted to the top surface of the bonnet and held in place with plastic clips.
Each washer jet is connected via a hose to an in-line valve. The in-line valve prevents the washer fluid draining back
to the reservoir and ensures that the washers operate immediately the washer pump is operated. From each in-line
valve the washers are connected via a short hose to a 'T' connector. From the 'T' connector a single hose connects
to the outlet of the front washer pump. Each jet has two jets which can be adjusted to allow full fluid coverage of the
windscreen.

WIPERS AND WASHERS
84-16 DESCRIPTION AND OPERATION
Headlamp powerwash pump
The headlamp power wash pump consists of a DC motor with an impeller. It is located on the front of the washer fluid
reservoir.
The BCU controls operation of the headlamp power wash relay, which supplies battery voltage from fuse 4 located in
the engine compartment fuse box to the headlamp power wash pump. When the BCU determines headlamp power
wash is to be activated, it provides a ground path for the coil of the headlamp power wash relay. The auxiliary relay
located in the engine compartment fuse box supplies the headlamp power wash relay coil with battery voltage.

CHARGING AND STARTING
86-1-2 REPAIRS
Refit
1.Clean mating faces of alternator and vacuum
pump.
2.Fit vacuum pump to alternator and tighten
bolts to 8 Nm (6 lbf.ft).
3.Position alternator to engine and connect
multiplug.
4.Connect vacuum hose and oil drain hose to
vacuum pump and secure clips.
5.With assistance align alternator to mounting
bracket and fit but do not tighten bolt.
6.Fit bolt securing support stay to alternator and
tighten to 25 Nm (18 lbf.ft) .
7.Tighten bolt securing alternator to mounting
bracket to 45 Nm (33 lbf.ft).
8.Using new 'O' ring, connect oil supply pipe to
cylinder head and tighten to 10 Nm (7 lbf.ft).
9.Connect lead to alternator and tighten nut to 6
Nm (4.4 lbf.ft).
10.Fit auxiliary drive belt tensioner and tighten bolt
to 50 Nm (37 lbf.ft).
11.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.

CHARGING AND STARTING
86-1-6 REPAIRS
Starter motor - diesel
$% 86.60.01
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.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.
4.Remove underbelly panel.

+ EXTERIOR FITTINGS, REPAIRS,
Panel - underbelly.
5.Disconnect Lucar connector from starter
solenoid.
6.Remove nut and disconnect battery lead from
starter solenoid.
7.Remove nut and 2 bolts securing starter motor
and remove starter motor from engine.Refit
1.Clean starter motor and mating face on engine.
2.Fit starter motor and tighten nut and 2 bolts to
27 Nm (20 lbf.ft).
3.Connect lead to starter solenoid and tighten nut
to 10 Nm (7 lbf.ft).
4.Connect Lucar connector to starter solenoid.
5.Fit underbelly panel.

+ EXTERIOR FITTINGS, REPAIRS,
Panel - underbelly.
6.Remove stand(s) and lower vehicle.
7.Connect battery earth lead.
8.Fit battery cover and secure the fixings.

CHARGING AND STARTING
REPAIRS 86-1-7
Starter motor - V8
$% 86.60.01
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.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.
4.Remove 3 nuts securing exhaust flange to
front pipe, release front pipe and collect
gasket.
5.Remove bolt securing heat shield to engine
mounting bracket, release heat shield from
starter motor and remove from vehicle.
6.Remove nut securing battery lead to starter
solenoid and release lead.
7.Disconnect Lucar connector from starter
solenoid.
8.Remove 2 Allen bolts securing starter motor
and remove starter motor from engine. Refit
1.Clean starter motor and mating face on engine.
2.Fit starter motor and tighten Allen bolts to 44
Nm (32 lbf.ft).
3.Connect Lucar connector to starter solenoid.
4.Fit battery lead to solenoid and tighten nut.
5.Position heat shield to starter motor, locate tag
in engine mounting bracket, fit bolt and tighten
to 10 Nm (7 lbf.ft).
6.Clean exhaust manifold and front pipe mating
faces.
7.Using a new gasket, position front pipe, fit nuts
and tighten to 30 Nm (22 lbf.ft).
8.Remove stand(s) and lower vehicle.
9.Connect battery earth lead.
10.Fit battery cover and secure fixings.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-1
BODY CONTROL UNIT DESCRIPTION AND OPERAT ION
Description
General
The Body Control Unit (BCU) is located behind the passenger glovebox and is connected to the main harness by four
connectors on its bottom edge and an additional connector located on the side of the BCU casing. Mounting the BCU
behind the fascia makes it reasonably inaccessible for intruders to disable the anti-theft system.
The BCU uses solid-state microprocessor control to perform logical operations and timing functions for a variety of
the vehicle's electrically operated systems, these include:
lDoor locking.
lAnti-theft alarm and immobilisation system.
lExterior lighting including direction indicators and hazard warning lamps.
lCourtesy lighting.
lWipers and washers.
lElectric windows and sunroof.
lHeated windows.
The BCU also communicates with several other electronically controlled systems such as the EAT ECU and SLABS
ECU and also has a datalink between the Intelligent Driver Module (IDM) and the instrument pack. The datalink is a
low speed bus capable of transmitting and receiving messages at a data rate of 10,400 bits per second. Additional
inputs and outputs to peripheral devices are included which are necessary for determining vehicle status for particular
logical operations e.g. crank, ignition key inserted, fuel flap enable etc.
The BCU receives its power supply from the engine compartment fuse box, and is protected by a 10 A fuse.
The BCU communicates with the IDM to provide the control signals to perform power switching operations in
conjunction with dedicated relays.
IDM
The IDM is integrated into the passenger compartment fuse box, which is mounted behind the fascia below the
steering column. There are no harnesses between the fuse box and the IDM. The IDM performs the power switching
operations for several of the vehicle's electrical systems.
The IDM communicates with the BCU and the instrument pack via a serial interface. If the BCU or the IDM is replaced,
the communications link between the two units has to be re-established. This can be done either by switching on the
ignition and leaving it on for five minutes, or by using TestBook. The vehicle immobilisation will remain active until the
communications link between the BCU and IDM has been re-established.
Transit mode
To prevent excessive battery drain during transit to overseas markets, the vehicle is placed in a transit mode. The
following functions are disabled when the vehicle is in transit mode:
lVolumetric sensors.
lPassive immobilisation.
lImmobilisation of the vehicle by use of door lock.
lIgnition key interlock.
lElectric seat enable time-out with driver's door open.

BODY CONTROL UNIT
86-3-2 DESCRIPTION AND OPERATION
Power supply
Battery supply to the BCU and the IDM is provided through a 10 A fuse located in the engine compartment fuse box.
The BCU unit receives an ignition switched power supply (ignition switch position II) input via a 10 A fuse in the
passenger compartment fuse box.
The BCU receives a signal when the ignition switch is turned to the crank position, it then supplies an earth path to
the starter relay coil, to enable the crank operation by supplying power through the starter relay contacts to the starter
motor.
Battery voltage is monitored and BCU operation will function normally between 8 and 18 volts. Between 5.7 and 8
volts the BCU is in the 'under volts' state. The status of the battery is used to determine which outputs may be driven.
If a voltage supply above 18 volts is experienced, outputs will not normally be driven except for those functions which
are required during cranking (robust immobilisation, antenna coil, crank enable relay and feed to gear position switch
contacts W, X, Y, Z). In the over voltage state the vehicle can be driven, but all other functions are disabled and
outputs are switched off (power windows, heated screen, direction indicators etc.).
All functions are disabled on power up until communications between the BCU and IDM have been established. If
communications cannot be established, operation will commence with degraded functionality.
Battery supply to the IDM is provided through the inertia switch and a 10 A fuse in the engine compartment fuse box.
If the inertia switch contacts are closed battery voltage is available at the IDM; if the inertia switch contacts are open
there is no battery supply to the IDM. The supply condition of the IDM is signalled to the BCU via the serial bus. If the
inertia switch is operated (contacts open) the change in state is detected by the BCU which unlocks the doors if the
ignition switch is in position II and the alarm is not set.
The BCU is earthed through a hard-wire connection.
Inputs and outputs
The BCU and IDM process inputs and provide the necessary outputs for control and operation of the vehicle's 'body'
systems.
BCU inputs
The BCU processes signals received from the following components:
lDoor latch switches.
lDriver's door key lock/ unlock switches.
lBonnet activated security system.
lVolumetric sensors.
lCentral Door Locking (CDL) switches.
lRemote transmitter (via receiver unit).
lInertia fuel cut-off switch.
lIgnition switch.
lFuel flap release switch.
The input voltages (V
in) for BCU digital signals are defined as follows:
lLogic 1 when V
in ≥ 6V.
lLogic 0 when V
in ≤ 2V.
BCU input voltages between 2 and 6 volts are indeterminate and cannot be guaranteed.
Analogue input voltages are measured as a ratio with respect to battery voltage.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-3
BCU outputs
The BCU processes the input signals it receives and uses the information to determine the control outputs that need
to be established for any given set of conditions. The BCU provides controlled outputs for the following systems:
lInterior courtesy lamps.
lFuel flap release actuator.
lAnti-theft status LED.
lEngine Control Module.
lDoor lock actuators.
lDirection indicators and hazard warning lamps.
lHeadlamps.
lAlarm sounder.
lVehicle horns.
lBattery backed sounder.
lStarter relay.
lPassive re-mobilisation exciter coil.
Simultaneous switching of outputs in different units is limited by the bus transfer time, but the skew is no longer than
100 ms for either the BCU or the IDM. When the processor is reset, all outputs are switched off until the inputs have
been read for the first time to check current condition.
BCU to harness connectors
1Connector C0661
2Connector C0662
3Connector C06634Connector C0660
5Connector C0664
The pinout details for the BCU connectors are defined below:

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-13
Anti-theft system
The BCU controls the logical switching operations for enabling and activating the anti-theft system. Features include:
lPerimetric protection – monitors the condition of doors and hinged panels.
lVolumetric protection – monitors the vehicle's interior space.
lRemote locking, superlocking and unlocking functions.
lEngine immobilisation and remobilisation.
lAdvanced mislock detection and automatic compensation.
lEKA code functions.
lCustomer configuration options.
lMarket configuration options.
Immobilisation
The immobilisation system comprises the following components:
lRF receiver.
lRF transmitter/ transponder.
lTransponder coil.
lBCU.
lDoor switches, door lock switches and bonnet switch.
lIDM.
lECM.
lStarter solenoid relay.
lStatus LED.
Alarm system
The alarm system comprises the following components:
lRF receiver.
lRF transmitter.
lBCU.
lIDM.
lDoor switches, door lock switches and bonnet switch.
lBattery backed-up sounder (BBUS).
lStatus LED.
On non NAS vehicles, power supply for the alarm sounder and the battery BBUS is provided through two relays in the
passenger compartment fuse box. Each of the coils of the alarm relays are directly connected to the IDM which
controls their operation under the direction of BCU signals received via the serial data bus.
On NAS vehicles, an audible warning is provided through operation of the vehicle horns. The BCU provides an earth
path for the coil of the horn relay to initiate vehicle horn operation.

+ ALARM SYSTEM AND HORN, DESCRIPTION AND OPERATION, Description.
Acclimatisation locking Disabled The vehicle cannot be locked if the ignition is on.
Enabled The vehicle can be locked if the ignition is on and the engine is
running.
Alarm tamper Disabled The security system LED does not flash when the security system has
been tampered with.
Enabled The security system LED flashes when the security system has been
tampered with.
Engine immobilised LED off The security system LED does not flash when the engine is
immobilised.
LED flash The security system LED flashes when the engine is immobilised.
Low battery warning Disabled The security system LED does not flash when the remote transmitter
battery is low.
Enabled The security system LED flashes when the remote transmitter battery
is low.
Emergency Key Access
(EKA)Disabled EKA is disabled.
Enabled EKA is enabled and the door locks operate electrically.
No unlock EKA is enabled, but the door locks do not operate electrically. Function Option Details

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-15
Electric seats
The BCU controls the logical operation of the electrically operated front seats. Two modes of operation are available:

+ SEATS, DESCRIPTION AND OPERATION, Description - electric seats.
lElectric seat adjustment is enabled if the ignition is on or the driver's door is opened for a short time period.
lElectric seat adjustment is enabled if the ignition is on and the driver's door is closed.
The seats are operated by four electric motors which control the seat cushion rear up/ down, the seat cushion front
up/ down, seat cushion forward/ rearward and seat squab recline. The electrically powered lumbar adjustment in each
seat is operated by a single motorised air pump and a solenoid located on the seat squab frame. The air pump inflates
a cushion in the seat squab and the solenoid operates a valve to deflate the cushion. The seat squab and cushion
may also contain heater elements to provide heated seat operation.
The switches for electrically operated seats are located either side of the centre console.
Direction indicators and hazard warning lamps
The direction indicator lamps are operated from a three position direction indicator switch on the left hand, steering
column stalk. The BCU only allows the lamps to work as direction indicators when the ignition switch is in position II.
The BCU also controls the lamps to operate as hazard warning lamps and as a visual warning for the anti-theft system,
in which cases all lamps flash simultaneously irrespective of the ignition switch position.
System control of the direction indicators and hazard warning lamps is provided by the BCU operating with the IDM
and two electronic relays located in the passenger compartment fuse box. The IDM and relays are integral parts of
the passenger compartment fuse box and cannot be serviced individually. The serial data bus is used for
communication of status and operation requests between the BCU, IDM and instrument pack.
The hazard warning lamps are operated from a latching pushbutton switch located on the fascia.
All direction indicator/ hazard warning lamp bulbs are rated at 5 Watts.
Headlamps
The BCU contains a feature which allow the vehicle headlamps to be turned on when the remote transmitter is
pressed (courtesy headlamps).
For markets with daylight running lamps, the BCU controls the logical operation of the daylight running lamps. Options
are daylight running lamps are on if the main beam headlamps are off, or the daylight running lamps are on with main
and dipped beam off and the gearbox not in Park.
Front fog lamps
For markets with front fog lamps fitted, the BCU controls the operation of the front fog lamps. Options can be selected
so that the fog lamps will operate with or without the headlamps on main beam.
Instrument pack
The BCU communicates with the instrument pack via a serial data bus.

+ INSTRUMENTS, DESCRIPTION AND OPERATION, Description.
lThe instrument pack provides the BCU and IDM with details of vehicle speed.
lSignals are provided from the IDM to the instrument pack and BCU when the direction indicator lamps are active.
lFor certain markets, the BCU provides a signal to the instrument pack for indicating when the transfer box is in
neutral.
lThe IDM can signal the instrument pack to illuminate a trailer warning lamp. This operates when the IDM senses
that the current drawn by the indicator circuit exceeds a preset threshold.
lThe odometer reading displayed on the instrument pack LCD screen is also stored in non volatile memory in the
BCU. Whenever the ignition is turned from position I to position II, the instrument pack and the BCU compare
their stored values.
lThe gear selector position is displayed on the instrument pack LCD screen under the direction of the BCU.
Starting
The starting system comprises a starter motor and solenoid located at the rear right hand side of the engine. A starter
relay controlled by the BCU is used to supply battery power for starter solenoid operation. The starter motor receives
its feed directly from the battery.