interior lights LAND ROVER DISCOVERY 1999 Workshop Manual

CONTENTS
26 CONTENTS
LIGHTING.................................................................................................. 86-2-1
ADJUSTMENTS
Headlamps beam alignment - up to 03MY ..................................................................................... 86-2-1
Headlamps beam alignment - from 03MY ...................................................................................... 86-2-2
REPAIRS
Lamp - front repeater - up to 03MY ................................................................................................ 86-2-3
Headlamp - up to 03MY .................................................................................................................. 86-2-4
Headlamp - from 03MY .................................................................................................................. 86-2-5
Lamp - tail ..................................................................................................................................... 86-2-6
Lamp - front fog up to 03MY ........................................................................................................... 86-2-6
Lamp - front fog from 03MY ............................................................................................................ 86-2-7
Housing - number plate lamp ......................................................................................................... 86-2-8
Motor - headlamp levelling ............................................................................................................ 86-2-9
Lamp - stop - centre high mounted (CHMSL) .............................................................................. 86-2-10
Lamp - tail/flasher - bumper ............................................................................................................ 86-2-10
Lamp - interior - front .................................................................................................................... 86-2-11
Lamp - interior - rear ..................................................................................................................... 86-2-11
Rheostat - panel lights dimmer ...................................................................................................... 86-2-12
Switch - hazard warning ................................................................................................................ 86-2-13
Switch - indicator and exterior lighting - combined ......................................................................... 86-2-13
Socket - accessory ........................................................................................................................ 86-2-14
Switch - front/rear fog lamps ......................................................................................................... 86-2-14
BODY CONTROL UNIT ............................................................................ 86-3-1
DESCRIPTION AND OPERATION
Description ...................................................................................................................................... 86-3-1
Operation ........................................................................................................................................ 86-3-19
REPAIRS
Body control unit (BCU) .................................................................................................................. 86-3-35
ALARM SYSTEM AND HORN.................................................................. 86-4-1
DESCRIPTION AND OPERATION
Alarm system component layout..................................................................................................... 86-4-2
Alarm system block diagram........................................................................................................... 86-4-4
Description ...................................................................................................................................... 86-4-5
Operation ........................................................................................................................................ 86-4-17
REPAIR
Switch - central door locking ......................................................................................................... 86-4-25
Switches - horn ............................................................................................................................. 86-4-25
Vehicle horn .................................................................................................................................. 86-4-26
Sounder - alarm ............................................................................................................................ 86-4-26
Sounder - battery backed-up (BBUS) ............................................................................................. 86-4-27
Switch - bonnet ............................................................................................................................. 86-4-27
Receiver - alarm system - models with sunroof ............................................................................. 86-4-28
Receiver - alarm system - models without sunroof ......................................................................... 86-4-28
Coil - passive immobilisation ........................................................................................................ 86-4-29

MAINTENANCE
PROCEDURES 10-5
Lamps, horns and warning indicators
Check
1.Switch on side, head and tail lamps and check
operation.
2.Check headlamp levelling operation.
3.Check turn signals and hazard warning lamps
for correct operation.
4.Press brake pedal and check operation of
brake lamps.
5.Check all exterior lamp lenses for clarity and
condition. Pay particular attention to headlamp
lenses for signs of stone chips or damage.
6.Check horn for loud, clear sound.
7.Switch on headlamps (with ignition switch at 'O'
position) and check light reminder warning
operates when door is opened.
8.Check operation of interior courtesy lights.
9.Check operation of all instrument pack warning
and indicator lights.
Wipers and washers
Check
1. Operate screen washer and switch on wipers.
Ensure washer jets are correctly aimed and
check for smooth, smear free operation of
wiper blades across screen at all speeds
including intermittent.
2.Repeat operation for rear screen washers/
wipers.
3.Check all wiper blades for condition and signs
of splits or damage.
4.Check security of wiper arms.

BODY CONTROL UNIT
86-3-30 DESCRIPTION AND OPERATION
Interior courtesy lamps
To determine when to provide an interior courtesy lamps enable output, the BCU checks the following input
conditions:
lIgnition state.
lTransit mode.
lDriver's door open.
lPassenger or rear door open.
The courtesy lamps operate at full brightness when they are first switched on. The BCU then gradually dims the lamps
(fade-out) before completely switching them off. Fade-out occurs over a period of two seconds following the logical
control signal to turn off the lights. When a door is opened, the BCU provides earth paths from the interior lamps, the
load space lamp and the ignition switch illumination. The following table lists the courtesy lamps operation and
duration for holding the lamps on that occurs after the BCU has detected a condition that signals the courtesy lamps
should be switched on:
Instrument pack
The BCU communicates with the instrument pack to provide a range of functions.
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.
Control signal Additional conditions Duration
Door open - 10 minutes
Unlock signal from remote transmitter All doors closed and ignition switch not in
position III1 minute
Unlock signal from the driver's door lock All doors closed and ignition switch not in
position III1 minute
Ignition switch turned from position II or III to
position 0All doors closed 1 minute
Door changed from open to closed All other doors closed and ignition switch not
in position III15 seconds
Ignition switch in position III - Timer cancelled
BCU receives a lock command - Timer cancelled
Vehicle has transit mode enabled - 15 seconds on all occasions