Defender now features an enhanced 10AS anti-theft alarm system, which incorporates Central Door Locking (CDL) in addition to perimetric and volumetric protection. The perimetric alarm function monitors the hinged panels of the vehicle. If any of the doors or the bonnet are opened while the alarm is armed, the alarm will be triggered. The volumetric alarm function monitors the interior space within the passenger compartment. If any movement is sensed while the alarm is armed, the alarm will be triggered.
To arm both the perimetric and volumetric functions, the vehicle should be locked using the RF handset.
CDL is functional on all doors, and is operated by pressing the appropriate button on the RF handset.
The anti-theft alarm ECU also interacts with the Engine Control Module (ECM), causing the engine to be immobilised whenever the alarm system is armed. For more details on engine immobilisation, refer to the Engine Immobilisation section of this manual.
Operation
Feed from the positive battery terminal (C0192) is supplied to the following on an N wire:
- Fuse 6
- Fuse 7
- Fusible link 1
- Fusible link 5
All are located in the under seat fuse box.
Fuse 6 (C0574) supplies a constant battery feed to the following:
- The anti-theft alarm ECU (C1979 on LHD vehicles, C0057 on RHD vehicles) on a PN wire
- The Battery Backed-Up Sounder (BBUS) (C0666) on a PN then B wire
- The anti-theft alarm relay (C0731) on a PN wire.
Fuse 7 (C0574) also supplies a constant battery feed to the anti-theft alarm ECU (C1980 on LHD, C0061 on RHD) on a PN wire.
Fusible link 1 is connected in series with fusible link 2, which is also located in the under seat fuse box. Fusible link 2 (C0570) supplies a constant battery feed to fuse 30 of the passenger compartment fuse box (C0595) on an NK wire. Fuse 30 (C0595) is connected to the anti-theft alarm LED (C1060) located in the instrument pack by a PN then NU wire.
Fusible link 5 (C0570) supplies a constant battery feed to the ignition switch (C1043 on LHD, C0028 on RHD) on an NW wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C1732 on LHD, C0094 on RHD) to fuse 8 of the passenger compartment fuse box (C0580) on a W wire. Fuse 8 (C0580) supplies an ignition feed to the anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) on a WG wire, and the BBUS (C0666) on a WG then B wire.
Door Switches
In order for the perimetric alarm system to operate, the anti-theft alarm ECU monitors the condition of the door switches. The door switches are open circuit when the doors are closed. When the doors are opened, the switches close and an earth path is created. The anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) is connected to the door switches as follows:
- To the driver door switch (C0266 on LHD, C2007 on RHD) on an SW wire
- To the front passenger door switch (C0265 on LHD, C0106 on RHD) on a PU wire
- To the LH rear passenger door switch (5 door vehicles only) (C0104) on a PU wire
- To the RH rear passenger door switch (5 door vehicles only) (C0108) on a PU wire
- To the tail door switch (C0615 on 90 Station Wagons, C1992 on 110 Station Wagons, C1993 on 90 Hard Tops, C1994 on 110 Hard Tops) on a PU wire.
NOTE: The anti-theft alarm ECU treats the passenger doors and the tail door as a single item.
Bonnet Switch
In addition to the door switches, the anti-theft alarm ECU also monitors the condition of the bonnet switch. The bonnet switch is open circuit when the bonnet is closed. When the bonnet is opened, the switch contacts close and an earth path is created.
The anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) provides a feed to the bonnet switch (C1981 on LHD, C0007 on RHD) on an OU wire. The switch is earthed on a B wire.
Volumetric Sensor
The anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) provides a feed to the volumetric sensor (C0719 on Truck Cabs, C0359 on Station Wagons) on a BN wire. The volumetric sensor (C0719 on Truck Cabs, C0359 on Station Wagons) is earthed on a B wire. When the alarm is armed, the volumetric sensor (C0719 on Truck Cabs, C0359 on Station Wagons) provides a feed to the anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) on a WB wire. If the sensor detects any movement within the passenger compartment, it replaces the feed with a pulsed signal. If the anti-theft alarm ECU receives a pulse of greater than 50 mS or three pulses within 1 second, it will trigger the alarm system.
Battery Backed-Up Sounder (BBUS)
Fuse 6 of the under seat fuse box (C0574) provides a constant battery feed to the BBUS (C0666) on a PN then B wire. The BBUS (C0666) is earthed on a B wire.
The anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) provides a battery voltage feed to the BBUS (C0666) on an OW then B wire. If the alarm is triggered, the anti-theft alarm ECU withdraws the feed and replaces it with an earth. By pulsing the feed/earth path, the anti-theft alarm ECU can control the operation of the BBUS. The anti-theft alarm ECU will re-introduce a permanent feed to the BBUS after approximately 4.5 minutes, or if the ignition is switched on. Fuse 8 of the passenger compartment fuse box (C0580) provides an ignition feed to the BBUS (C0666) on a WG then B wire.
NOTE: The BBUS is not fitted in all markets.
Alarm Sounder
Fuse 6 of the under seat fuse box (C0574) provides a constant battery feed to the alarm relay (C0731) on a PN wire. The earth path for the relay coil is controlled by the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD). The anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) provides a battery voltage feed to the alarm relay coil (C0731) on an OW wire. To energise the relay, the anti-theft alarm ECU withdraws the feed and replaces it with an earth. Battery voltage from fuse 6 is now able to flow across the closed relay contacts (C0731) to the sounder (C0520) on an OB wire. The sounder (C0520) is earthed on a B wire. By pulsing the feed/earth path to the alarm relay, the anti-theft alarm ECU can control the operation of the sounder.
NOTE: The alarm sounder is not fitted in all markets.
Horns
Fuse 6 of the under seat fuse box (C0574) provides a constant battery feed to the alarm relay (C0731) on a PN wire. The earth path for the relay coil is controlled by the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD). The anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) provides a battery voltage feed to the alarm relay coil (C0731) on an OW wire. To energise the relay, the anti-theft alarm ECU withdraws the feed and replaces it with an earth. Battery voltage from fuse 6 is now able to flow across the closed relay contacts (C0731) to fuse 27 of the passenger compartment fuse box (C0581) on an OR wire. Fuse 27 (C0581) provides a feed to the LH horn (C0003) and the RH horn (C0004) on PB wires. By pulsing the feed/earth path to the alarm relay, the anti-theft alarm ECU can control the operation of the horns.
Anti-theft Alarm LED
The anti-theft alarm LED is located in the instrument pack, and is supplied a constant battery feed from fuse 30 of the passenger compartment fuse box (C0595) on a PN then NU wire. The earth path for the LED (C1060) is controlled by the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) on a K wire. To extinguish the LED, the ECU supplies a voltage equal to that of battery voltage along the K wire. To illuminate the LED, the ECU withdraws the feed and replaces it with an earth path. By switching from a feed to an earth path, the ECU can control the flashing sequence of the LED.
Hazard Warning Lamps
The anti-theft alarm ECU is able to control the flashing sequence of the hazard warning lamps. When the alarm is first armed, the hazard warning lamps will flash three times. When the alarm is disarmed, the hazard warning lamps will flash once. If the alarm is triggered, the hazard warning lamps will flash until the alarm system is disarmed.
To illuminate the RH hazard warning lamps, the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) provides a feed to the hazard warning switch (C0096) on a GW wire. Simultaneously, the anti-theft alarm ECU provides a feed to the hazard warning switch (C0096) on a GR wire to illuminate the LH hazard warning lamps.
NOTE: When the alarm is triggered, the anti-theft alarm ECU flashes the hazard warning lamps alternately with the BBUS/alarm sounder.
For more information on the hazard warning lamps, refer to the Direction Indicator/Hazard Warning Lamps section of this manual.
Door Lock Motors
When the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) receives a valid lock signal from the RF handset, it provides a feed to the following on K wires:
- To the driver door lock motor (C0342)
- To the front passenger door lock motor (C0327)
- To the RH rear passenger door lock motor (C1996)
- To the LH rear passenger door lock motor (C1996)
- To the tail door lock motor (C0617).
NOTE: The RH rear and LH rear door lock motors have the same connector numbers as they utilise the same harness.
Current flows across the motors and back to the anti-theft alarm ECU (C1980 on LHD, C0057 on RHD) on O wires. When the anti-theft alarm ECU receives a valid unlock signal from the RF handset, it provides a feed to the door motors on O wires. Current flows across the motors and back to the anti-theft alarm ECU on K wires.
Interior Lamps
The anti-theft alarm ECU will illuminate the interior lamps under the following conditions:
- If the alarm system is disarmed using the remote handset
- If a door or the tail door is opened.
The anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) provides a feed to the front interior lamp (C0355) and the rear interior lamp (C0356 on 90 Station Wagons, C0357 on 110 Station Wagons) on PW wires.
For more information on interior lamp operation, refer to the Interior Lamps – Anti-theft Alarm section of this manual.
Diagnostic Socket
The anti-theft alarm system can be interrogated using TestBook via the diagnostic socket. The diagnostic socket (C0040) is connected to the anti-theft alarm ECU (C1979 on LHD, C0061 on RHD) by an LG wire.