stop start LAND ROVER DISCOVERY 2002 Owner's Manual

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.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-23
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.
A timeout function is included which allows the windows and sunroofs to be operated for a period of 44
± 1 seconds
after the ignition key has been removed from the ignition switch. The timeout function will be cancelled if the BCU
detects the following conditions:
lThe driver's door has been closed after the ignition has been switched off.
lAny door open after the ignition is switched off.
The preconditions are programmed into the BCU dependent on market specification.
The BCU does not directly control rear window operation, but it can request the IDM to remove the power feed to the
rear windows. The IDM enables power supply to be provided to the rear lift relay in the passenger fuse box. When the
relay coil is energised the relay contacts close and power is applied to the rear window motor. If the window lift
isolation switch located in the centre console is latched out, the earth path from the LH and RH rear door window
switches is broken and operation of the rear window motors through the use of the rear window switches is prevented.
Rear window operation using the console switches is not affected by the isolation switch.
In the event of a communications link failure occurring while rear window enable is on, the relay remains on until the
ignition switch is turned to the off position.

BODY CONTROL UNIT
86-3-32 DESCRIPTION AND OPERATION
Odometer update
The BCU can be programmed for one of two options:
lOption 1 – no odometer error warning.
lOption 2 – odometer error warning.
In order to provide an LCD flash request to the instrument pack via the communications link, the following inputs are
checked:
lIgnition state.
lInstrument pack odometer value (via the communications link).
lBCU odometer value.
The function is only active when the ignition state is on. The maximum allowed value is 999,999 miles (1,608,999
km).If the instrument pack odometer value is greater than the maximum allowed value, the maximum value is
assumed. The BCU odometer value is stored in EEPROM. If 16 identical values of the instrument pack odometer
reading is received consecutively, the instrument pack odometer value is compared with the BCU odometer value. If
the consecutive readings from the instrument pack differ, the BCU odometer value is incremented accordingly. If the
BCU odometer value is less than the instrument pack odometer value by up to 10 km, the BCU odometer value is set
equal to the instrument pack odometer value.
If the odometer warning option is enabled, and the contents of the instrument pack odometer value buffer is identical
to, or greater than BCU odometer value
± 10 km, the BCU sends an LED flash request to the instrument pack.
In the event of a communications link failure, this function will be unable to operate.
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.

ALARM SYSTEM AND HORN
86-4-20 DESCRIPTION AND OPERATION
Mislock
Mislock alerts the driver that a failed attempt has been made to lock the vehicle because of the doors or the bonnet
not being fully closed.
There are six audible configurations for mislock:
lNo audible warning.
lAlarm sounder.
lVehicle horn.
lAlarm sounder and vehicle horn.
lBBUS.
lAlarm sounder, vehicle horn and BBUS.
When a failed attempt has been made to lock the vehicle, the audible warning device is switched on for 50 ms and
off for 200 ms. The BCU allows the audible warning device to operate 3 times.
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.

ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION 86-4-21
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.
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.

NAVIGATION SYSTEM
87-8 DESCRIPTION AND OPERATION
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.
A = Distance, miles (km); B = Start/Finish point
Reset
If the navigation system malfunctions, a system reset can be triggered by simultaneously pressing the TP button and
multifunction button 1 or 3. The navigation CD will need to be installed after the system reset.

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.