1999 LAND ROVER DEFENDER door lock

ELECTRICAL
3
DESCRIPTION AND OPERATION ANTI-THEFT ALARM - FROM 02MY
The alarm and immobilisation system on 2002MY Defender is similar to that used on Discovery Series I (LJ)
models from 1996MY. The alarm system comprises the anti-theft alarm ECU, bonnet and door switches and a
volumetric sensor.
Anti-Theft Alarm ECU
The anti-theft alarm ECU is located behind the instrument pack and receives a permanent battery supply via fuses
6 and 7 in the under seat fuse box. The ECU also receives a battery supply via the ignition switch position II and
fuse 1 in the passenger compartment fuse box. The ECU is connected to the various supporting components by
two harness connectors.
The ECU controls the alarm system (perimetric and volumetric security), CDL system, engine immobilisation
system (Td5 only) and various other vehicle functions including direction indicators and interior lamps.
The anti-theft alarm ECU incorporates an RF receiver and antenna for reception of RF signals from the remote
handset for locking and alarm arming. The antenna is unterminated at one end, and for optimum performance the
antenna must not be wound around adjoining harnesses.
The anti-theft alarm ECU operates at one of two frequencies which are identified by a label on the unit. The
frequencies are:
433 MHz - Europe, Gulf States, South Africa
315 MHz - North America, South East Asia, Japan, Australia.
The anti-theft alarm ECU also incorporates an integral inertia switch. In the event of an impact of sufficient severity
to trigger the inertia switch when the ignition is on, the ECU will unlock all doors and operate the hazard warning
lamps. The ECU will remain in this condition for a pre-programmed period of 2 minutes. To reinstate CDL
functionality and to deactivate the hazard warning lamps, the ignition should be turned off and then on after the 2
minute timer has expired.
NOTE: There is a separate inertia switch for fuel cut off.
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86ELECTRICAL
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DESCRIPTION AND OPERATION Door and Bonnet Switches
The bonnet switch is located at the rear of the bonnet aperture on the bulkhead. The door switches are located on
the’A’posts for the front doors, the’B’posts for the rear doors and on the inside face of the tail door aperture.
The drivers door switch and the bonnet switch are connected to the anti-theft alarm ECU on individual single
wires. The remaining passenger doors and, if applicable, the tail door are jointly connected on a single wire to the
ECU. If a fault occurs which involves incorrect mislock signals, alarm triggers and interior lamp operation, the door
switch earth may be the cause of incorrect operation.
If any door or the bonnet is opened, the switch closes and completes an earth path to the anti-theft alarm ECU.
This completed earth path input is sensed by the ECU, which, if armed, will sound the BBUS or alarm sounder.
The ECU also controls, via the door switches and ignition on/off signals, the operation of the interior lamps.
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ELECTRICAL
5
DESCRIPTION AND OPERATION Perimetric Protection
Perimetric protection is the monitoring of each opening door or bonnet to unauthorised intrusion. The anti-theft
alarm ECU uses the door and bonnet switches described previously to determine when illegal intrusion has
occurred.
If a door/bonnet is left open when the alarm system is armed, the ECU will determine a mislock situation which is
indicated by non operation of the hazard warning lamps. If the drivers door is left open, the security LED in the
instrument pack will be illuminated for the 10 second confirmation period. If any other door or the bonnet is left
open the security LED will remain off for the 10 second confirmation period. After the confirmation period, the LED
will revert to the 1Hz deterrent flash.
If the door/bonnetis subsequently closed, the hazard warning lamps will flash to show that full perimetric protection
is now invoked. The security LED will also resume the 10 second confirmation flash.
If only the bonnet is left open, all doors will have perimetric protection and volumetric protection will also be set. If
a door is left open, the volumetric protection is suspended until that door is subsequently closed.
Volumetric Protection
The vehicle alarm system can be armed with or without volumetric protection activated. If volumetric protection is
required, the vehicle must be locked using the lock button on the remote handset. If volumetric protection is not
required, because a pet is to be left in the vehicle for instance, the vehicle must be locked using the vehicle key in
the drivers door lock.
When the vehicle is locked using the remote handset, the volumetric sensor will wait for a period of 15 seconds
before arming. This allows time for the air in the vehicle to settle and prevent incorrect activation of the alarm.
If volumetric protection is set and there is a disturbance in the vehicle, i.e., a window left open or a moving object
in the vehicle, within the 15 second period, the volumetric sensor will not activate. The sensor must detect no
disturbance for the full 15 second period before arming.
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ELECTRICAL
9
DESCRIPTION AND OPERATION Security LED
The security LED has a number of functions to indicate anti-theft alarm system status. The LED is located in the
speedometer housing in the instrument pack. The LED receives a permanent battery supply via fusible link 6 in
the under seat fuse box. The LED is connected to the anti-theft alarm ECU which earths the connection when LED
operation is required. When the LED is not required to be illuminated, the anti-theft alarm ECU holds the
connection at battery voltage, keeping the LED extinguished.
When the system is armed and the bonnet and all doors are closed, the LED flashes quickly for a 10 second
confirmation period and confirms that perimetric and volumetric systems are armed. After the 10 second
confirmation period the LED flash changes to a slow flash to confirm that the alarm and immobiliser systems are
armed and to act as deterrent to thieves.
The LED also conveys CDL system information and this functionality is described in the Central Door Locking
(CDL) section.
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86ELECTRICAL
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DESCRIPTION AND OPERATION Remote Handset
The remote handset is a separate unit from the vehicle key and is used to arm and disarm the alarm system. The
handset comprises two buttons; lock and unlock. The handset contains a battery (CR3032) and a printed circuit
board containing the circuitry to generate the RF signals.
NOTE: In selected markets, the vehicle key, when used in the drivers door key barrel switch, will
not disarm the alarm system.
The remote handset RF code consists of two parts. One part is a fixed code that is unique to the handset and the
second part is a rolling code which changes in accordance with a predetermined pattern. The anti-theft alarm ECU
can store the codes of up to four different remote handsets at any one time.
If the remote handset battery falls below a predetermined level, the handset will transmit an additional RF signal
code to the anti-theft alarm ECU when either button is depressed. The security LED will display this as two rapid
flashes every 0.5 seconds to visually display the low handset battery condition. This will continue for the 10
second confirmation period or until the ignition is switched on.
Resynchronisation of Remote Handset
If either the remote handset battery or the vehicle battery is removed or disconnected, the rolling part the handset
code is lost and the handset(s) need to be resynchronised to the anti-theft alarm ECU. The resynchronisation
procedure is as follows:
Disconnect the vehicle battery.
Wait for 30 seconds for residual current to dissipate.
Reconnect the vehicle battery.
Carefully prise the remote handset apart and remove the battery. Avoid unnecessary handling of the battery.
With the battery removed, press either the lock or unlock button several times to remove residual current from
the circuitry.
Check the handset battery with a voltmeter. If the battery voltage is less than 2.7 volts, replace the battery.
Ensure that the battery contact surfaces are clean and replace the battery in the handset clip with the + symbol
uppermost. Put the two halves of the handset case back together.
DO NOT press any buttons.
With the handset within range of the vehicle, press the lock button four times in quick succession. The
anti-theft alarm ECU will respond by locking the vehicle.
Press the unlock button once to complete the resynchronisation procedure.
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ELECTRICAL
13
DESCRIPTION AND OPERATION Passive Immobilisation
Passive immobilisation occurs when the key is removed from the ignition switch and the drivers door is opened,
after a period of 30 seconds the engine will become immobilised. If the ignition is turned off or the key is removed
from the ignition switch and drivers door is not opened, the engine will become immobilised after 5 minutes.
The passive immobilisation system operates in conjunction with the transponder coil located around the ignition
switch barrel. The transponder coil emits an electro magnetic waveform signal which excites the remote handset
into transmitting a remobilisation signal. When remobilisation is requested, the anti-theft alarm ECU transmits an
appropriate code to the ECM on Td5 models or the engine immobilisation ECU on 300Tdi models.
Active immobilisation
Active immobilisation is only invoked when the vehicle is locked using the remote handset. Active immobilisation
performs the same engine disable functionality as the passive immobilisation previously described, but includes
full CDL and activation of perimetric and volumetric alarm modes.
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86ELECTRICAL
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DESCRIPTION AND OPERATION Emergency Key Access (EKA)
If the vehicle is in an immobilised condition and the remote handset is not available or inoperable, an EKA
procedure using the vehicle key is available to remobilise the engine systems. The EKA code is supplied with the
vehicle and is shown on the security card supplied with the owners handbook.
NOTE: This feature is only available in markets where full alarm functionality is specified.
The EKA code involves the input of a unique four digit code which is entered using the ignition switch and the
drivers door switch. Note that the alarm sounder will operate as soon as the drivers door is opened and will
continue until the sequence is successfully completed.
To enter the code (2, 3, 4, 5 for example) perform the following steps:
1.Remove the handset from the key ring and position the handset well away from the ignition switch when
entering the code.
2.Open the driver’s door and immediately insert the key in the ignition switch and turn the ignition switch to
position II. Hold this position until the alarm sounds, then switch the ignition off (position 0) and close the
driver’s door.
3.Enter the first digit of the code. Turn the ignition on (to position II) and then off twice. Open and close the
driver’s door to enter the first digit.
4.Enter the second digit. Turn the ignition on and then off, three times. Open and close the driver’s door to
enter the second digit.
5.Enter the third digit. Turn the ignition on and then off, four times. Open and close the driver’s door to enter
the third digit.
6.Enter the fourth digit. Turn the ignition on and then off, five times. Open and close the driver’s door to enter
the fourth digit. If the code has been entered correctly, the alarm LED in the instrument pack will extinguish
and the engine can be started after the last closure of the driver’s door.
If a digit is incorrectly entered, holding the ignition switch in the on position for more than 5 seconds will reset the
sequence. The code must then be re-entered from the beginning.
If the EKA code is correctly entered, the security LED will illuminate for 1 second, the immobilisation will be
disabled and the alarm sounder will cease to operate.
If the EKA code is incorrectly entered, the alarm sounder will sound twice and the correct code must be
re-entered, If the EKA code is incorrectly entered three times the system invokes a 30 minute lockout. This is
signalled by the LED flashing with a long illuminated period followed by a short extinguished period for the lockout
duration.
NOTE: Disabling the alarm and immobilisation system using the EKA procedure is only valid for
one ignition on/off cycle. When the ignition is switched off, the immobilisation system will be
activated after a period of 30 seconds. If the remote handset is still unavailable, the EKA
procedure will have to be repeated each time the vehicle is to be driven.
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ELECTRICAL
15
DESCRIPTION AND OPERATION CENTRAL DOOR LOCKING (CDL) - FROM 02MY
The Central Door Locking (CDL) system is a new feature for 2002MY Defender.
NOTE: CDL operates all doors on Station Wagon and County Station Wagons. On all other
Defender 2002MY variants, CDL operates on the driver and front and rear passenger doors only.
General
CDL operates on all doors, including the tail door and is operated by pressing the appropriate button on the
remote handset, using the vehicle key in the drivers door lock or using the drivers door sill button.
The CDL system introduces electrically operated door latches which are controlled by the anti-theft alarm ECU,
located behind the instrument pack. The anti-theft ECU receives a permanent power supply from fuse 6 in the
passenger compartment fuse box. Each CDL latch motor is connected by two wires to the anti-theft ECU which
alternately supplies power and earth connections to drive each motor to the lock or unlock positions.
If the latch motors are continually operated in a short period of time, the anti-theft ECU will suspend all CDL latch
motor operation for 15 seconds to prevent the motors from overheating. Before suspension occurs the anti-theft
ECU ensures that all the doors are left in the unlocked condition.
If the vehicle is locked, and the key is in the ignition switch or the ignition is on and the anti-theft alarm ECU inertia
switch is tripped, all doors will be unlocked immediately and the hazard warning lamps will operate. To prevent
accidental relocking, all latch motors will be inhibited until the anti-theft ECU senses that the drivers door is
opened with the key removed from the ignition switch.
Locking of the vehicle using the remote handset is inhibited with the key in the ignition switch.
Slam Locking
With the introduction of CDL, slam locking of the drivers door is disabled. If an attempt is made to slam lock the
vehicle, the anti-theft alarm ECU will unlock all doors.
CDL Using the Drivers Door Sill Button
Each door has a sill button to allow that door to be individually locked from inside the vehicle. The drivers door sill
button has additional functionality which allows all doors to be locked from inside the vehicle from this one button.
When the driver door sill lock button is depressed, the CDL system enters a sill locked state, where all doors are
locked but immobilisation and perimetric and volumetric sensing is suspended. CDL using the drivers sill lock
button can be achieved with or without the key in the ignition switch and without the ignition being on.
If the CDL is in the sill locked state and the lock button on the remote handset is pressed, the volumetric and
perimetric functions of the alarm system will become active and active engine immobilisation will be invoked.
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