Workshop Manuals Factory service & repair Land Rover
01 Discovery Series II - Workshop Manual - 1999MY ON - 6th Edition - NAS02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 INTRODUCTION32 33 GENERAL INFORMATION34 35 GENERAL DATA36 IDENTIFICATION NUMBERS37 38 TORQUE WRENCH SETTINGS39 40 LIFTING AND TOWING41 CAPACITIES, FLUIDS, LUBRICANTS AND SEALANTS42 43 44 MAINTENANCE45 46 ENGINE - V847 48 EMISSION CONTROL - V849 50 ENGINE MANAGEMENT SYSTEM - V851 FUEL DELIVERY SYSTEM - V852 53 COOLING SYSTEM - V854 55 MANIFOLDS AND EXHAUST SYSTEMS - V856 57 58 59 CLUTCH - V860 61 MANUAL GEARBOX - R38062 63 TRANSFER BOX - LT230SE64 65 66 AUTOMATIC GEARBOX - ZF4HP22 - 2467 PROPELLER SHAFTS68 69 REAR AXLE70 71 72 73 74 75 FRONT AXLE76 77 78 79 STEERING80 FRONT SUSPENSION81 82 83 REAR SUSPENSION84 85 86 87 BRAKES88 RESTRAINT SYSTEMS89 90 DOORS91 EXTERIOR FITTINGS92 93 INTERIOR TRIM COMPONENTS94 SCREENS95 96 97 SEATS98 99 SUNROOF100 CHASSIS AND BODY DIMENSIONS101 102 103 104 PANEL REPAIRS105 106 107 108 BODY SEALING MATERIALS109 110 111 112 113 CORROSION PREVENTION AND SEALING114 PAINTING115 HEATING AND VENTILATION116 117 AIR CONDITIONING118 119 WIPERS AND WASHERS120 CHARGING AND STARTING121 122 LIGHTING123 BODY CONTROL UNIT124 125 126 ALARM SYSTEM AND HORN127 128 WINDOWS129 IN CAR ENTERTAINMENT130 HARNESSES131 DRIVING AIDS132 NAVIGATION SYSTEM133 INSTRUMENTS
Land Rover Discovery II126 · ALARM SYSTEM AND HORN
126 · Electrical

ALARM SYSTEM AND HORN: DESCRIPTION AND OPERATION (page 4 of 8)

Make
Land Rover
Model
Discovery II
ALARM SYSTEM AND HORNDESCRIPTION AND OPERATION · page 4 of 8
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ALARM SYSTEM AND HORN

86-4-20 DESCRIPTION AND OPERATION

Super locking
Super locking prevents the use of the interior door handles to unlock and open the vehicle doors. This prevents the 
doors from being opened if the window be smashed in an attempt to gain access to the vehicle.

There are four configurations for super locking:

l

No super locking.

l

Super locking on single handset press only (no key activated super locking).

l

Super locking on single handset press or single key turn.

l

Super locking on double handset press or double key turn.

To super lock, press the lock button on the handset once or twice within one second depending on system 
configuration.  In some configurations, it is also possible to super lock the vehicle using the key in the driver's door.  
This also may require one or two turns of the key in the lock direction.  If two turns of the key are required to activate 
super locking, the two turns must occur within one second of each other.

In order to super lock the vehicle, the following conditions must be met:

l

All door are closed.

l

The ignition is off.

l

The fuel cut-off switch is not tripped. 

Partial arming
Partial arming allows protection of as much of the vehicle as possible if the alarm is armed with one or more doors or 
the bonnet open.

Partial arming allows the vehicle alarm to be armed even if the following conditions exist. When the bonnet or door is 
closed, the BCU activates the perimetric alarm and the volumetric alarm after 15 seconds have elapsed:

l

The bonnet is not closed: If the bonnet is open when the alarm is armed, the BCU activates super locking and 
volumetric sensing. In this condition, the alarm enters a partially armed state. All other functions of the alarm are 
active and the BCU monitors the bonnet for a change of state. If the bonnet closes, the system is completely 
armed.

l

The passenger door, a rear door or the tail door is not closed: If a door is open when the alarm is armed, the BCU 
does not activate super locking or volumetric sensing. In this condition the alarm enters a partially armed state. 
All other alarm functions are armed and the BCU monitors the open door. If the door closes volumetric sensing 
and super locking become active.

l

Failure of a door latch switch: If a short circuit in the door latch switch occurs, the BCU presumes the door is not 
closed. In this situation the BCU does not activate super locking or volumetric sensing. All other alarm functions 
are armed.

l

Damaged wiring harness: If a short circuit in the wiring harness for the door latch switch occurs, the BCU 
presumes the door is not closed and does not activate super locking or volumetric sensing; all other alarm 
functions are armed. If an open circuit in the wiring harness for the door latch switch occurs, the BCU presumes 
the door is closed and arms the alarm as normal.

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:

l

No audible warning.

l

Alarm sounder.

l

Vehicle horn.

l

Alarm sounder and vehicle horn.

l

BBUS.

l

Alarm 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. 

Parts & tools for this job Staging For Land Rover Discovery

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