1999 LAND ROVER DISCOVERY stop start

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-19
Operation
For IDM inputs which are also inputs for BCU functions, the delay before the BCU recognises the change in input
status is less than 250 ms. The BCU uses a debounce algorithm to ignore changes in input having a duration less
than 100 ms with the exception of automatic gearbox W, X, Y, Z inputs, which have a debounce period of 33 ms.
Transit mode
To prevent excessive battery drain during transit to overseas markets, the vehicle is placed in a transit mode.
To exit the transit mode, simultaneously hold down the heated rear window switch and the rear fog lamp switch, turn
the ignition switch from 0 to II and, after a minimum of 2 seconds, release the switches.
Transit mode can be entered using TestBook. When TestBook communicates with the BCU for diagnostics related to
BCU operation, it first checks that the vehicle is not in transit mode.
Anti-theft system
The BCU uses the driver's door key lock and unlock switches to activate and deactivate the security system. The
driver's door lock is also used for entering the EKA.

+ ALARM SYSTEM AND HORN, DESCRIPTION AND OPERATION, Description.
Immobilisation
For immobilisation, the BCU disables the starter motor relay. When the engine is cranking, the ECM looks for a coded
signal from the BCU. If the signal is not received within one second of cranking, the fuel supply to the engine is
stopped and the injectors are disabled. This also prevents unburnt fuel from entering the catalyst.
If the BCU is disconnected, the engine starter motor will remain isolated by the starter motor relay and the ECM will
remain immobilised. The main wiring for the system is contained within the main harness which is relatively
inaccessible, so preventing intruders from disabling the system by cutting the wires for the immobilisation system.
Once the immobiliser has been activated, destruction of the trigger device or the wiring to it will not disarm the system.
The RF transmitter communicates to the BCU via the RF receiver using a 70 bit code. Pressing the unlock button on
the transmitter will re-mobilise the vehicle. The RF transponder is integrated into the metal key assembly, inserting
the key into the ignition switch will induce a signal in the exciter coil to re-mobilise the vehicle.
Anti-theft alarm
The alarm system provides a warning of unauthorised access to the vehicle and includes perimetric and volumetric
monitoring under the control of the BCU.
The perimetric protection system detects opening of all doors, tail door and bonnet and will also detect the operation
of the ignition key switch. The following conditions must be satisfied before the BCU will operate all of the functions
of perimetric protection:
lAll doors and hinged panels are in the closed position.
lIgnition key out of the ignition switch.
lInertia switch is not tripped.
If all conditions are not satisfied the BCU will enter a mislock condition.
The volumetric sensor uses two ultrasonic sensors mounted in the headlining to detect movement within the vehicle.
The alarm will trigger when the sensor signals the BCU for 200 ms or greater. Within a single setting period the alarm
system will allow a maximum of 10 triggers as a result of any combination of sensor inputs. It is possible to lock the
vehicle without enabling the volumetric alarm by using the key. The same conditions needed to satisfy enabling of the
perimetric protection system is also needed to enable volumetric protection.
When the alarm system is set the BCU checks the status of all the inputs from the door and bonnet switches to ensure
the integrity of the vehicle before setting the alarm system into operational mode. In some markets, when the alarm
is set the BCU sends a signal to the IDM which will cause the direction indicators to flash three times for a duration of
3 seconds.
If the sensors are triggered the BCU will activate an alarm sounder to provide an audible warning of a theft attempt.
The activation period of the alarm sounder is 25 to 30 seconds. The duty cycle of the alarm sounder is 50:50 ± 10%.

BODY CONTROL UNIT
86-3-22 DESCRIPTION AND OPERATION
Electric windows and sunroof
Three modes of operation are available:
lDriver cancel – the front windows, rear windows and sunroof will be disabled 44 seconds after the driver's door
is opened.
lAll cancel – The front windows, rear windows and sunroof will be disabled 44 seconds after any door is opened.
lNo cancel – the front windows, rear windows and sunroof will be disabled when the ignition is turned off.
The BCU will allow window and sunroof operation when the ignition key is in position II. The BCU provides a voltage
to the window control switches. When the switches are pressed, they provide a path to earth to complete the circuit
and initiate window operation. Window and sunroof operation is suspended when the ignition switch is in the crank
position.
For front window operation, the BCU checks the status of the following inputs:
lIgnition state.
lDriver's door open.
lPassenger or rear door open.
lFront right window down.
lFront right window up.
lFront left window down.
lFront left window up.
lRight window stall detect.
lLeft window stall detect.
The front window motors are directly connected to the BCU by two wires. Each wire can be used as a feed or return,
dependent on the required direction for motor operation (open or close). The BCU provides the following outputs:
lRight window up.
lRight window down.
lLeft window up.
lLeft window down.
The electric front windows are enabled when the ignition switch is in position II and is disabled if the ignition switch is
moved to the crank position.
The BCU checks the status of the following inputs to determine when to provide the rear window enable and sunroof
enable output signals:
lIgnition state.
lDriver's door open.
lPassenger or rear door open.
The rear window enable and sunroof enable lines are on when the ignition switch is in position II, and are switched
off if the ignition switch is moved to the crank position.
The BCU monitors the circuit current draw when the windows are operating to detect the occurrence of a stall
condition. If the BCU determines that the window has stalled, it will cut the power supply to stop the operation of the
window motor. The BCU only starts to check for a stall condition after the window has been operating for 500 ms. This
delay period enables the initial current surge to pass and eliminates false detections of window stall. A stall condition
is activated when a nominal current value is exceeded for a period greater than 300 ms.
If the BCU detects that it has been operating the same window motor in one direction for more than 10 ± 0.2 seconds,
without the BCU detecting a stall condition or the control switch being released, it will automatically stop operation of
the window motor (timed out). Window operation can resume when the window switch is released and pressed again.
If the window was operating in one touch mode, the window operation will resume on the next press of the window
switch.
One touch mode automatically lowers the window to its fully open position, without the need for the window switch to
be kept pressed for the duration of the window travel. One touch mode is initialised if the window switch is pressed
for a period of less than 0.4 ± 0.2 second. One touch mode continues to lower the window until the BCU detects:
lA stall condition exists (window has reached bottom of travel).
lWindow switch is repressed in either direction for more than 0.4 ± 0.2 second.
lThe BCU has operated the motor for a period greater than 10 ± 0.2 seconds.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-31
Gear position indicator illumination
On automatic gearbox models, two variations of illumination for the gear position indicators on the selector lever can
be programmed into the BCU. In option 1, illumination is provided when the ignition is on. In option 2, illumination is
enabled when the ignition is on and the side lamps are off.
Starter relay
The BCU checks the status of the following inputs and internal BCU conditions to determine whether or not to provide
an output to enable the starter relay:
lAutostart inhibit (vehicles with automatic gearbox only).
lSecurity start inhibit (immobilisation check).
lEngine running (link to instrument pack).
lEEPROM locked (internal check).
lIDM and BCU matched.
When the BCU receives a crank signal from the ignition switch, an earth path is completed to the starter relay coil,
provided that the security system has been de-activated. If the ECM has not received a valid unlock/ remobilise signal,
the starter relay will be disengaged and the engine stopped. The BCU also receives an engine running signal from
the instrument pack, so that if the ignition key is turned to the crank position while the engine is running, the starter
motor relay will not be engaged.
If the logic conditions are correct to allow starter operation, the completion of the earth path from the starter relay coil
to the BCU energises the coil and the relay contacts close to supply battery power to the starter motor.
When the ignition switch is released from the crank position, the power supply feed from the ignition switch to the
starter relay coil is interrupted and the relay contacts open to prevent further battery feed to the starter motor.
If a communications link failure is experienced, the BCU will be prevented from detecting the 'engine running'
condition and the BCU will default to assume that the engine is not running.
Cruise control
The Neutral/ Reverse/ Park/ Brake selected output is used by the cruise control system. The BCU checks for the
following inputs:
lIgnition on.
lGearbox state.
lBrake switch activated.
For vehicles with manual transmission, Neutral/ Reverse/ Park/ Brake selected output is on if the ignition is on and
brake switch activated is on. Otherwise, the Neutral/ Reverse/ Park/ Brake selected output is off.
For vehicles with automatic transmission, the Neutral/ Reverse/ Park/ Brake selected output is on if the ignition is on
and brake switch activated is on, or if the ignition is on and 'gearbox state' is in Neutral, Park or Reverse. Otherwise
Neutral/ Reverse/ Park/ Brake selected output is off.
Shift interlock (where fitted)
On automatic gearbox models, the BCU and IDM combine to operate a shift interlock solenoid, so that the gear
selector lever can only be moved when certain logical conditions have been satisfied. Operation of the interlock may
be affected, if the battery becomes discharged.

+ AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.
When the gear selector lever is in the Park position and the ignition is off, an interlock solenoid is de-energised, locking
the gear selector lever in the Park position.
The gear selector lever can only be moved from the Park position when the ignition is switched on and the brake pedal
is depressed. When these conditions are satisfied, the brake pedal switch signal is received by the BCU which then
signals the IDM to energise the interlock relay. When the interlock relay is energised, the interlock solenoid is
operated, unlocking the gear selector lever.
When the brake pedal is released, the feed to the BCU is removed and the shift interlock solenoid is de-energised.
The locking mechanism controlled by the solenoid will lock the gear selector lever once it is returned to the Park
position.

ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION 86-4-21
Passive immobilisation
Passive immobilisation prevents the vehicle from being started unless the authorised key is used to start the vehicle.
There are only two configurations for passive immobilisation:
lpassive immobilisation not active
lpassive immobilisation active
When the ignition is switched off, the vehicle remains mobilised for up to a maximum of 5 minutes. If however the
driver's door is opened, after 2 minutes 30 seconds, the vehicle remains in a mobilised state for a further 30 seconds.
When the timer in the BCU has expired, the vehicle is immobilised.
Once the ignition is switched on, the BCU transmits a coded signal to the ECM. If the coded signal does not
correspond to the programmed code in the ECM, the ECM is inhibited and the BCU inhibits the starting circuit.
In order for passive immobilisation to occur, the following conditions must be met:
lDriver's door closed.
lFuel cut-off switch not tripped.
lKey not inserted in ignition.
Passive remobilisation
Whenever the vehicle is immobilised, passive remobilisation of the engine occurs when the ignition is switched on,
allowing the vehicle to be started.
There are three configurations for passive remobilisation:
lPassive immobilisation not active.
lPassive immobilisation active.
lEKA with super locking on receiving good passive remobilisation exciter coil signal.
The BCU controls the passive remobilisation exciter coil (located around the ignition barrel) to generate a magnetic
field which causes the handset to transmit a remobilisation signal. The BCU receives the signal and allows the vehicle
to be started. If a valid signal from the handset is not received within one minute of the ignition being switched to
position II, the BCU stops the passive coil from generating the magnetic field.
Emergency key access
If the handset fails to operate, the engine can be remobilised by using the key to enter a unique four digit Emergency
Key Access (EKA) code.
There are three configurations for emergency key access:
lEKA not active (no immobiliser fitted).
lEKA active.
lEKA with super locking on receiving good passive remobilisation exciter coil signal.

ALARM SYSTEM AND HORN
86-4-22 DESCRIPTION AND OPERATION
The code is recorded on the security information card and is entered as follows:
1Using the key, turn the driver's door lock to the UNLOCK position and hold in this position for at least 5 seconds.
An audible warning is then emitted to indicate that the body control unit is ready to accept the code. Return the
key to the centre position. It is now possible to use the key to enter the separate numerical values of the four
digits that make up the EKA code.
2Enter the first digit of the code. If the first digit is 4, turn the key to the UNLOCK position 4 times. Ensure the
key is fully returned to the centre position after each turn of the key.
3Enter the second digit of the code. If the second digit is 3, turn the key to the LOCK position 3 times. Ensure
the key is fully returned to the centre position after each turn of the key.
4Enter the third digit of the code. If the third digit is 2, turn the key to the UNLOCK position twice. Ensure the key
is fully returned to the centre position after each turn of the key.
5Enter the fourth digit of the code. If the fourth digit is 1, turn the key to the LOCK position once. Ensure the key
is fully returned to the centre position after each turn of the key.
6Finally, turn the key to the UNLOCK position and back to the centre position, a double bleep will indicate that
the code has been entered correctly. A single bleep indicates that the code has been entered incorrectly.
Then, before opening the door, wait 5 minutes for the alarm and immobiliser to be de-activated. During the 5
minute wait for the alarm and immobiliser to be de-activated, the alarm indicator LED in the instrument pack
continues to flash (one flash every 2 seconds). DO NOT OPEN THE DOOR OR ATTEMPT TO ENTER THE
CAR until the full delay period has elapsed.
When the 5 minute wait has elapsed, the alarm indicator LED stops flashing. Immediately open the door, insert
the key in the ignition switch and turn the switch to position II. If the ignition switch is not turned to position II
within 30 seconds of the end of the 5 minute wait, the engine is automatically immobilised again.
The EKA code will not be recognised if there is an interval of 10 seconds or more between key turns or if the key is
held turned for 5 seconds or more during the procedure.
In some system configurations a successful EKA code entry is indicated by the audible warning device pulsing twice
for a period of 50 ms on, 200 ms off. The theft deterrent LED is switched on for 1 second, all doors unlock, the alarm
disarms and the vehicle is remobilised allowing the engine to start.
If an incorrect code is entered, an audible warning is emitted and the procedure must be repeated. Up to a maximum
of 10 attempts to enter the code is possible. After 10 attempts, the BCU will not allow any further codes to be entered
for a period of 10 minutes.
Single point entry
Single point entry (SPE) allows the driver to unlock the driver's door while leaving all other doors locked.
There are two configurations for single point entry:
lSPE not active.
lSPE active.
To use SPE, press the unlock button on the handset once. Depressing the unlock button a second time in the space
of one minute unlocks the remaining doors. SPE is also possible by turning the key in the driver's door lock to the
unlock position once. Turning the key to the unlock position again within one minute unlocks the remaining doors.
In order for SPE to operate, the following conditions must be met:
lThe ignition is off.
lAll doors are locked.
Speed related locking
For added protection the vehicle doors can automatically lock when the vehicle exceeds a specific road speed.
There are two configurations for speed related locking:
lSpeed related locking not active.
lSpeed related locking active.
Speed related locking causes the doors to automatically lock when the vehicle exceeds a speed of 4 mph (7 km/h).
When the ignition is switched off, the doors are automatically unlocked. Depressing the instrument panel mounted
central door unlocking switch disables the speed related locking for the duration of the journey.
Speed related locking only activates once per ignition cycle. If speed related locking activates and a door is then
unlocked, the door does not automatically re-lock.

IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-27
Operation
DVD Player Functionality
The following defines the functionality of the unit. Further details of system operation can found in the DVD System
Owner's Manual, Publication Part No. LRL0482, supplied with the system.
DVD Region Selection
The DVD player is capable of playing discs from any region. The DVD can only be set to play discs of one region at
a time. A code is entered using the remote control handset to set the unit to the required region. The unit is set to the
correct region on production and therefore this will not be required by either the dealer or the customer.
If the unit region is required to be changed for any reason, Land Rover Special Vehicles must be contacted for the
required code and procedure.
NOTE: The unit can be re-configured for region up to five times. After the fifth attempt to re-configure the region, the
unit will be locked in the fifth region that was programmed. This will require the unit to be returned to the manufacturer
to be reset. The manufacturer will charge a fee for this service.
DVD Player CD Audio Function
The DVD player can play audio CD's through the vehicle audio system. This allows the user to play additional CD's
without having to remove the CD autochanger cartridge.
The overhead console LCD monitor must be open to play audio CD's.. Normal audio CD functionality such as repeat,
random and track select etc. can be accessed using the remote control handset.
The DVD player in the overhead console will also function independently of the vehicle audio system, and operate as
an additional CD player. The rear seat passengers can listen to audio CD's via the three headphone sockets on the
overhead console and via the two radio/headphone amplifier units (if fitted), while the front seat passengers
simultaneously listen to CD's played on the vehicle audio system and CD autochanger.
DVD/CD Output using the Vehicle Audio System
To play the DVD/CD audio output from the overhead console through the vehicle audio speakers, the speaker button
on the overhead console or remote control handset must be pressed. 'Speaker On' appears on the LCD monitor and
the head unit CD functionality is suspended. The audio output from the overhead console will now be played from the
vehicle speaker system. The head unit volume control, tone control, Navigation announcements and mobile phone (if
fitted) will function as normal and override the DVD output. A second press of the speaker button will switch the audio
output back to the head unit. 'Speaker Off' will be displayed on the LCD monitor.
The overhead console will remember the selected speaker condition if the overhead console is switched off by closing
the monitor, the console switched off using the handset or accessory power removed from the overhead console.
Power Up Conditions
On application of accessory power, the overhead console will perform the following:
lIf no disc is in the DVD player, the LCD monitor will display a blue screen and enter 'AUX' input mode.
When a DVD or CD is inserted in the DVD player, the system will change to DVD input mode. The disc will
attempt to play but may be limited by the disc media. Some discs will play automatically, some will display a menu
and others require the user to start playback.
lIf a disc was in the DVD player and the system was in 'Play', 'Pause', 'FF' or 'Rew' when powered down, playback
will start when power is re-applied.
lIf a disc was in the DVD player and the system was in 'Stop' when powered down, the system will enter DVD
mode and a blue screen will be displayed on the LCD monitor.
lSpeaker selection will remain in the same state as when the accessory power was removed.
Engine Cranking
If the unit is playing a DVD or CD when the ignition switch is moved to position III (engine crank), the system will stop
playing while the engine is cranking. Playback will resume at the point the playback was stopped when the ignition
switch is returned to position I or II.

NAVIGATION SYSTEM
87-8 DESCRIPTION AND OPERATION
Calibration Routine
1Park the vehicle outside in an area clear of high buildings, trees etc.
NOTE: The more open the surrounding area is, the faster the system will acquire sufficient GPS satellite signals to
begin calibration. To minimise the calibration time, the vehicle should not be moved again until the calibration
ride.
2Turn the ignition switch to position II. If the navigation computer does not come on, press the navigation
computer ON button.
3If necessary, use the navigation computer multifunction buttons to enter the security code.
4Turn the ignition switch to position 0 and remove the ignition key.
5Press the navigation computer ON button.
6Call up the SENSORS screen on the LCD:
lIf the navigation CD-ROM has not been installed before, press and hold multifunction button 1 then press
multifunction button 10.
lIf the navigation CD-ROM has been installed before, use the garage menu as detailed above.
7Turn the LH rotary control to minimum volume.
8Wait for 30 minutes. If necessary, the vehicle can be left unattended and locked.
NOTE: Land Rover recommend a minimum of 30 minutes be allowed to elapse in order to ensure that only a short
distance need be driven to achieve calibration.
9After the 30 minutes have elapsed, ensure the navigation computer LCD shows a GPS almanac figure of 27 or
higher.
10Start the vehicle engine and allow to idle.
11Install the navigation CD-ROM.
12Wait until the navigation computer LCD prompts for a language to be selected. Turn the RH rotary control to
scroll through the options, highlight the required language and press the RH rotary control to select.
13The navigation computer LCD will prompt for a voice to be selected. Turn the RH rotary control to scroll through
the options, highlight the required voice and press the RH rotary control to select.
14Wait until the navigation computer LCD advises "language has been loaded OK". Press the RH rotary control to
confirm the language and voice selections.
15The navigation computer LCD will default to the CALIBRATION RIDE screen and should show the
CALIBRATION RIDE CAN START message. The GPS data and the road speed counter will also be shown.
16Drive the vehicle over a road route approximating that shown below (it is not necessary to copy the route
exactly). Calibration is complete when the navigation computer LCD switches to show DESTINATION & POI
and the satellite graphic. If all the pre calibration ride conditions were complied with, calibration is typically
achieved within 3 miles (5 km) and usually occurs when the vehicle returns to the start point. However,
calibration may be achieved earlier in the journey and, if it is, there is no need to complete the remainder of the
calibration route.
17After calibration is achieved, return to the dealership, park the vehicle and stop the engine.
18Turn the ignition switch to position I.
19Use the system settings menu to set the navigation computer to local time and the required units of measure:
aPress the Nav button.
bTurn the RH rotary control to scroll through the displayed menu, highlight TIME and press the RH rotary
control to select. Press the + or – multifunction button to adjust the time in 30 minute steps. Select the 24
hour clock and confirm by pressing the OK multifunction button.
cIf metric units of measure are required, go to step e) (the navigation computer defaults to metric units of
measure).
dIf Imperial units of measure are required, turn the RH rotary control to scroll through the displayed menu,
highlight MEASURING UNIT and press the RH rotary control to select. Turn the RH rotary control to
highlight IMPERIAL and press the RH rotary control to select.
ePress the Nav button to return to the destination menu.
20Calibration is complete. The navigation system is ready for use.
NOTE: The accuracy of the system will automatically be fine tuned when a further journey is made, but this is not
required as part of the calibration procedure.
NOTE: In European countries, the territory will have to be set the first time the navigation system is used, and the
first time a destination in another country is selected. The first time the navigation system is used or a destination
in another country is selected, a map is displayed with the default/current territory highlighted. To change the
territory: Press the RH rotary control to display the territory list; turn the RH rotary control to scroll through the
list and highlight the required territory; press the RH rotary control to confirm the selection.

INSTRUMENTS
88-36 DESCRIPTION AND OPERATION
Self Levelling Suspension (SLS) warning lamp
The SLS warning lamp within the instrument pack utilises an amber LED and a clear legend. The SLABS ECU
illuminates the LED continuously if a fault within the SLS is detected, providing the driver with a visible warning.
When the ignition is switched on the SLABS ECU illuminates the LED to provide a self-check, providing there is no
fault it will remain illuminated for 3 seconds or until the ignition is switched off.
On vehicles equipped with coil springs the SLS warning lamp is extinguished after 850 milliseconds if the SLABS ECU
configuration of the vehicle is correct.
The SLS warning lamp flashes at 2 Hz when the remote handset control is used to raise or lower the ride height.
If a new SLABS ECU is installed the SLS warning lamp will remain illuminated until the ECU has been calibrated by
TestBook.
The warning lamp will illuminate continuously when battery voltage is less than 10 volts for greater than 1 second.
When the vehicle is in transportation mode the SLS warning lamp is illuminated continuously with ignition on, and will
flash at 2 Hz frequency as the vehicle rises from bump stop level to transport level on engine start.
The power input for the LED is supplied by the instrument pack via fuse 27. The SLABS ECU provides the earth path
to illuminate the warning lamp.
The voltage on the earth path from the SLABS ECU to the instrument pack has the following functions:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.