key battery LAND ROVER DISCOVERY 2002 User Guide

RESTRAINT SYSTEMS
REPAIRS 75-21
Refit
CAUTION: The SRS diagnostic control unit
is a shock sensitive device and must be
handled with extreme care.
1.Position DCU to body and connect multiplug.
2.Fit and tighten DCU Torx bolts to 10 Nm (7
lbf.ft).
3.Fit centre console.
lOn manual gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
lOn automatic gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
4.Connect battery leads, earth lead last.
Rotary coupler
$% 76.74.20
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove steering wheel.

+ STEERING, REPAIRS, Steering
wheel.
3.Remove steering column nacelle.

+ STEERING, REPAIRS, Nacelle -
steering column.

INTERIOR TRIM COMPONENTS
REPAIRS 76-3-9
16.Remove console.
NOTE: Do not carry out further dismantling if
component is removed for access only.
17.Remove 4 screws securing storage bin lid to
console and remove lid.
18.Release cigar lighter body from console and
remove.
Refit
1.Fit and secure cigar lighter body to console.
2.Fit lid to console and secure with screws.
3.Fit console.
4.Connect multiplug and bulb to cigar lighter.
5.Fit centre console to fascia.
6.Fit 2 bolts securing rear of console to
transmission tunnel.
7.Connect multiplugs to seat switches.
8.Fit switches to console.
9.Move handbrake to lowered position.
10.Fit cable to handbrake and secure with clevis
pin and clip.
11.Fit handbrake gaiter to console.
12.Fit bolts securing forward edge of console to
transmission tunnel.
13. Models with veneer trim: Position veneered
console cover and connect multiplugs to switch
pack. Fit cigar lighter element and secure
veneered console cover to console.
14. Models with base trim: Connect multiplugs to
switch pack, fit switch pack to console and
secure with screws.
15. Models with base trim: Fit cover plate to
switch pack, and rubber mat to console.
16.Fit transfer gearbox gaiter and knob to lever.
17.Secure gaiter to console.
18.Fit knob and gaiter to gear lever and secure
gear lever gaiter to console with clips.
19. Models from 03MY:Fit both centre console
cup holders.
Fascia
$% 76.46.23/99
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove radio cassette player.

+ IN CAR ENTERTAINMENT,
REPAIRS, Radio cassette player.
3.Remove steering wheel.

+ STEERING, REPAIRS, Steering
wheel.
4.Remove steering column nacelle.

+ STEERING, REPAIRS, Nacelle -
steering column.
5.Remove centre console.
lFor models with automatic gearbox:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
lFor models with manual gearbox:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
6.Remove 'A' post trim panels.

LIGHTING
ADJUSTMENTS 86-2-1
LIGHTING ADJUST ME NTS
Headlamps beam alignment - up to 03MY
$% 86.40.17
Check
1.Ensure vehicle is unladen and tyres are at
correct pressures.
2. Models with SLS: Ensure vehicle is at
standard ride height.
3. Models with headlamp levelling: Ensure
headlamp levelling switch is set to '0'.
4.Align suitable beam setting equipment to
headlamp.
5.Switch headlamps on and measure main beam
settings. Beam must be 1.4% below the
horizontal and parallel to the vehicle centre line.
If necessary, adjust headlamp to get correct
beam settings.
6.Align beam setting equipment to 2nd headlamp
and repeat check.
7.Switch off headlamps and remove beam setting
equipment.
Adjust
1. For RH headlamps: Release fixings and
remove battery cover
2.Remove headlamp access cover.3.Turn vertical adjuster as necessary to get
correct beam setting. Use a 7 mm Allen key for
models with headlamp levelling, or a 10 mm
spanner for models without headlamp levelling.
4.Turn horizontal adjuster as necessary to get
correct beam setting. Use a 10 mm spanner.
5.Fit headlamp access cover.
6. For RH headlamp adjustment: Fit battery
cover and secure fixings.

LIGHTING
REPAIRS 86-2-13
Switch - hazard warning
$% 86.65.50
Remove
1.Carefully remove switch.
2.Disconnect multiplug from switch.
3.Remove switch.
Refit
1.Connect multiplug switch.
2.Position switch and push to secure.
Switch - indicator and exterior lighting -
combined
$% 86.65.55
WARNING: Always remove the key from the
starter switch, disconnect the vehicle battery and
wait 10 minutes before commencing work on the
SRS system.
Remove
1.Remove rotary coupler.

+ RESTRAINT SYSTEMS, REPAIRS,
Rotary coupler.
2.Remove 2 screws securing switch.
3.Carefully raise edge of switch bracket to clear
location peg and release switch from bracket.
4.Disconnect 2 multiplugs and remove switch.
Refit
1.Position switch and connect multiplugs.
2.Fit switch to bracket and secure with screws.
3.Fit rotary coupler.

+ RESTRAINT SYSTEMS, REPAIRS,
Rotary coupler.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-1
BODY CONTROL UNIT DESCRIPTION AND OPERAT ION
Description
General
The Body Control Unit (BCU) is located behind the passenger glovebox and is connected to the main harness by four
connectors on its bottom edge and an additional connector located on the side of the BCU casing. Mounting the BCU
behind the fascia makes it reasonably inaccessible for intruders to disable the anti-theft system.
The BCU uses solid-state microprocessor control to perform logical operations and timing functions for a variety of
the vehicle's electrically operated systems, these include:
lDoor locking.
lAnti-theft alarm and immobilisation system.
lExterior lighting including direction indicators and hazard warning lamps.
lCourtesy lighting.
lWipers and washers.
lElectric windows and sunroof.
lHeated windows.
The BCU also communicates with several other electronically controlled systems such as the EAT ECU and SLABS
ECU and also has a datalink between the Intelligent Driver Module (IDM) and the instrument pack. The datalink is a
low speed bus capable of transmitting and receiving messages at a data rate of 10,400 bits per second. Additional
inputs and outputs to peripheral devices are included which are necessary for determining vehicle status for particular
logical operations e.g. crank, ignition key inserted, fuel flap enable etc.
The BCU receives its power supply from the engine compartment fuse box, and is protected by a 10 A fuse.
The BCU communicates with the IDM to provide the control signals to perform power switching operations in
conjunction with dedicated relays.
IDM
The IDM is integrated into the passenger compartment fuse box, which is mounted behind the fascia below the
steering column. There are no harnesses between the fuse box and the IDM. The IDM performs the power switching
operations for several of the vehicle's electrical systems.
The IDM communicates with the BCU and the instrument pack via a serial interface. If the BCU or the IDM is replaced,
the communications link between the two units has to be re-established. This can be done either by switching on the
ignition and leaving it on for five minutes, or by using TestBook. The vehicle immobilisation will remain active until the
communications link between the BCU and IDM has been re-established.
Transit mode
To prevent excessive battery drain during transit to overseas markets, the vehicle is placed in a transit mode. The
following functions are disabled when the vehicle is in transit mode:
lVolumetric sensors.
lPassive immobilisation.
lImmobilisation of the vehicle by use of door lock.
lIgnition key interlock.
lElectric seat enable time-out with driver's door open.

BODY CONTROL UNIT
86-3-2 DESCRIPTION AND OPERATION
Power supply
Battery supply to the BCU and the IDM is provided through a 10 A fuse located in the engine compartment fuse box.
The BCU unit receives an ignition switched power supply (ignition switch position II) input via a 10 A fuse in the
passenger compartment fuse box.
The BCU receives a signal when the ignition switch is turned to the crank position, it then supplies an earth path to
the starter relay coil, to enable the crank operation by supplying power through the starter relay contacts to the starter
motor.
Battery voltage is monitored and BCU operation will function normally between 8 and 18 volts. Between 5.7 and 8
volts the BCU is in the 'under volts' state. The status of the battery is used to determine which outputs may be driven.
If a voltage supply above 18 volts is experienced, outputs will not normally be driven except for those functions which
are required during cranking (robust immobilisation, antenna coil, crank enable relay and feed to gear position switch
contacts W, X, Y, Z). In the over voltage state the vehicle can be driven, but all other functions are disabled and
outputs are switched off (power windows, heated screen, direction indicators etc.).
All functions are disabled on power up until communications between the BCU and IDM have been established. If
communications cannot be established, operation will commence with degraded functionality.
Battery supply to the IDM is provided through the inertia switch and a 10 A fuse in the engine compartment fuse box.
If the inertia switch contacts are closed battery voltage is available at the IDM; if the inertia switch contacts are open
there is no battery supply to the IDM. The supply condition of the IDM is signalled to the BCU via the serial bus. If the
inertia switch is operated (contacts open) the change in state is detected by the BCU which unlocks the doors if the
ignition switch is in position II and the alarm is not set.
The BCU is earthed through a hard-wire connection.
Inputs and outputs
The BCU and IDM process inputs and provide the necessary outputs for control and operation of the vehicle's 'body'
systems.
BCU inputs
The BCU processes signals received from the following components:
lDoor latch switches.
lDriver's door key lock/ unlock switches.
lBonnet activated security system.
lVolumetric sensors.
lCentral Door Locking (CDL) switches.
lRemote transmitter (via receiver unit).
lInertia fuel cut-off switch.
lIgnition switch.
lFuel flap release switch.
The input voltages (V
in) for BCU digital signals are defined as follows:
lLogic 1 when V
in ≥ 6V.
lLogic 0 when V
in ≤ 2V.
BCU input voltages between 2 and 6 volts are indeterminate and cannot be guaranteed.
Analogue input voltages are measured as a ratio with respect to battery voltage.

BODY CONTROL UNIT
86-3-4 DESCRIPTION AND OPERATION
The pinout details for the BCU connectors are defined below:
C0660 connector pin details
Pin No. Description Input/Output
1 Ignition power supply Input
2 Right front window - down Input
3 Auxiliary power supply Input
4 Passenger or rear door open Input
5 Driver's door key lock Input
6 RH indicator selected Input
7 Front fog lamps selected Input
8 Gear position feedback 'R' Output
9 Gear position feedback 'P' Output
10 SLS too high (audible warning) Input
11 Earth-
12 Vehicle raise/lower request Output
13 Battery power supply Input
14 Heated front screen selected Input
15 Bonnet open Input
16 CDL doors lock Input
17 Driver's door open Input
18 Left front window up Input
19 Right front window up Input
20 Rear washer pump Input
21 Front intermittent wiper switch Input
22 Gear position feedback '1' Output
23 Gear position feedback '2' Output
24 Gear position feedback '3' Output
25 Gear position feedback 'D' Output
26 Gear position feedback 'N' Output

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-5
C0661 connector pin details
Pin No. Description Input/Output
1 Serial bus to instrument pack and IDM Input/Output
2 Not used-
3 Battery backed up sounder code (AL) Output
4 Diagnostic bi-directional 'K'-line Input/Output
5 RF regulated power supply Output
6 RF receiver input Input
7 Brake switch activated Input
8 Reverse gear selected Input
9 Sunroof enable line Output
10 Robust immobilisation Output
11 Front washer pump Input
12 Heated front screen relay Output
13 Heated front screen active Output
14 Battery backed up sounder code (ST) Output
15 Heated rear screen active Output
16 'N' or 'R' or 'P' or brake selected Output
17 Not used-
18 Passive remobilisation exciter coil Output
19 RF battery supply from fuse 20 in passenger compartment fusebox Input
20 Security status LED Output
21 Front intermittent wiper Input
22 Driver's door key unlock Input

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-13
Anti-theft system
The BCU controls the logical switching operations for enabling and activating the anti-theft system. Features include:
lPerimetric protection – monitors the condition of doors and hinged panels.
lVolumetric protection – monitors the vehicle's interior space.
lRemote locking, superlocking and unlocking functions.
lEngine immobilisation and remobilisation.
lAdvanced mislock detection and automatic compensation.
lEKA code functions.
lCustomer configuration options.
lMarket configuration options.
Immobilisation
The immobilisation system comprises the following components:
lRF receiver.
lRF transmitter/ transponder.
lTransponder coil.
lBCU.
lDoor switches, door lock switches and bonnet switch.
lIDM.
lECM.
lStarter solenoid relay.
lStatus LED.
Alarm sounder Alarm Audible warnings are given by the security system sounder only.
Both Audible warnings are given by both the security system sounder
and the vehicle horn.
Vehicle Audible warnings are given by the vehicle horn only.
BBUS Audible warnings are given by the security system sounder,
vehicle horn and BBUS.
Disabled Audible warnings are not given.
Acclimatisation locking Disabled The vehicle cannot be locked if the ignition is on.
Enabled The vehicle can be locked if the ignition is on and the engine is
running.
Alarm tamper Disabled The security system LED does not flash when the security system
has been tampered with.
Enabled The security system LED flashes when the security system has
been tampered with.
Engine immobilised LED off The security system LED does not flash when the engine is
immobilised.
LED flash The security system LED flashes when the engine is immobilised.
Low battery warning Disabled The security system LED does not flash when the remote
transmitter battery is low.
Enabled The security system LED flashes when the remote transmitter
battery is low.
Emergency Key Access
(EKA)Disabled EKA is disabled.
Enabled EKA is enabled and the door locks operate electrically.
No unlock EKA is enabled, but the door locks do not operate electrically. Function Option Details

BODY CONTROL UNIT
86-3-14 DESCRIPTION AND OPERATION
Alarm system
The alarm system comprises the following components:
lRF receiver.
lRF transmitter.
lBCU.
lIDM.
lDoor switches, door lock switches and bonnet switch.
lBattery backed-up sounder (BBUS).
lStatus LED.
On non NAS vehicles, power supply for the alarm sounder and the battery BBUS is provided through two relays in the
passenger compartment fuse box. Each of the coils of the alarm relays are directly connected to the IDM which
controls their operation under the direction of BCU signals received via the serial data bus.
On NAS vehicles, an audible warning is provided through operation of the vehicle horns. The BCU provides an earth
path for the coil of the horn relay to initiate vehicle horn operation.

+ ALARM SYSTEM AND HORN, DESCRIPTION AND OPERATION, Description.
Central Door Locking (CDL)
The BCU carries out the logic control operation for CDL. A CDL switch is mounted on the fascia panel and has two
inputs to the BCU, one for lock and one for unlock.
Door locking and unlocking can be performed using the remote transmitter in the keys and the receiver unit located
above the vehicle's headlining, behind the rear sunroof aperture. The receiver detects the signals sent from the
remote transmitter and sends a decoded signal to the BCU for processing.
Four methods of door locking are available:
lRemote handset locking.
lVehicle key locking.
lCDL switch locking.
lSpeed related locking.
Two security levels of door locking are available, CDL and Superlocking. The anti-theft alarm system works in
conjunction with the CDL system.
Electric windows and sunroof
The BCU controls the logical operations and the timing periods for the electric front windows. The rear windows are
hard-wired and the two electric sunroofs are controlled by a dedicated ECU which is enabled by the BCU.
The front windows are electrically operated using two rocker switches located in the centre console. Electric motors
are located in each of the front doors.
The rear windows are enabled by the IDM controlling the operation of the rear window relay located in the passenger
compartment fuse box.
Wipers and washers
The wiper and washer functions are controlled by the BCU and the IDM.
The front wipers and washers are operated from the switch stalk located on the right hand side of the steering column
and only operate when the ignition switch is in position I or II. The front wipers are operated by a motor located below
the windscreen plenum.

+ WIPERS AND WASHERS, DESCRIPTION AND OPERATION, Description.