2002 LAND ROVER DISCOVERY alarm

PANEL REPAIRS
REPAIRS 77-2-27
11.Fit headlamp.

+ LIGHTING, REPAIRS, Headlamp - up
to 03MY.
12. Diesel models: Fit gearbox fluid cooler.
13. Models with A/C: Fit condensor.

+ AIR CONDITIONING, REPAIRS,
Condenser.
14.Fit washer reservoir.

+ WIPERS AND WASHERS, REPAIRS,
Reservoir - washer - up to 03MY.
15.Connect leads/multiplug to alternator.
16.Connect battery leads, negative lead last.
Valance upper assembly - LH
In this procedure, the front wing, the valance outer
reinforcement and the bonnet alarm switch mounting
bracket are replaced in conjunction with the LH
valance upper assembly.
Remove
1.Disconnect both battery leads, negative lead
first.
2.Disconnect leads/multiplug from alternator.
3.Remove front wing.

+ EXTERIOR FITTINGS, REPAIRS,
Wing - front - up to 03MY.
4.Remove air filter assembly.

+ ENGINE MANAGEMENT SYSTEM -
V8, REPAIRS, Air cleaner assembly.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Air filter assembly.
5.Remove PAS/ACE reservoir.
6.Remove ABS modulator.

+ BRAKES, REPAIRS, Modulator unit
- ABS.
7.Remove brake pipes from valance.
8.Release harness from valance and position
aside.
9. Models with A/C: Depressurise A/C system
and remove pipes from valance.

+ AIR CONDITIONING, REFRIGERANT
RECOVERY, RECYCLING AND
RECHARGING, Refrigerant recovery,
recycling and recharging.

PANEL REPAIRS
77-2-30 REPAIRS
Valance upper assembly (front section) -
LH
In this procedure, the front wing, the valance outer
reinforcement (front section) and the bonnet alarm
switch mounting bracket are replaced in conjunction
with the LH valance upper assembly (front section).
Remove
1.Disconnect both battery leads, negative lead
first.
2.Disconnect leads/multiplug from alternator.
3.Remove front wing.

+ EXTERIOR FITTINGS, REPAIRS,
Wing - front - up to 03MY.
4.Remove air filter assembly.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Air filter assembly.

+ ENGINE MANAGEMENT SYSTEM -
V8, REPAIRS, Air cleaner assembly.
5.Remove PAS/ACE reservoir.
6.Remove ABS modulator.

+ BRAKES, REPAIRS, Modulator unit
- ABS.
7.Release harness from valance and position
aside.
8. Models with A/C: Depressurise A/C system
and remove pipes from valance.

+ AIR CONDITIONING, REFRIGERANT
RECOVERY, RECYCLING AND
RECHARGING, Refrigerant recovery,
recycling and recharging.Repair
1.Remove existing panel(s), prepare panel joint
faces and install new panel(s) in accordance
with Panel Replacement Procedure. Punch or
drill holes in new panel for plug welding as
shown.
Refit
1. Models with A/C: Fit A/C pipes and recharge
A/C system.

+ AIR CONDITIONING, REFRIGERANT
RECOVERY, RECYCLING AND
RECHARGING, Refrigerant recovery,
recycling and recharging.
2.Fit harness to valance.
3.Fit ABS modulator.

+ BRAKES, REPAIRS, Modulator unit
- ABS.
4.Fit PAS/ACE reservoir and refill fluids to correct
levels.

+ FRONT SUSPENSION,
ADJUSTMENTS, ACE hydraulic system
bleeding.

+ CAPACITIES, FLUIDS AND
LUBRICANTS, Fluids.
M77 1744
M77 1689A

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
DESCRIPTION AND OPERATION 86-3-3
BCU outputs
The BCU processes the input signals it receives and uses the information to determine the control outputs that need
to be established for any given set of conditions. The BCU provides controlled outputs for the following systems:
lInterior courtesy lamps.
lFuel flap release actuator.
lAnti-theft status LED.
lEngine Control Module.
lDoor lock actuators.
lDirection indicators and hazard warning lamps.
lHeadlamps.
lAlarm sounder.
lVehicle horns.
lBattery backed sounder.
lStarter relay.
lPassive re-mobilisation exciter coil.
Simultaneous switching of outputs in different units is limited by the bus transfer time, but the skew is no longer than
100 ms for either the BCU or the IDM. When the processor is reset, all outputs are switched off until the inputs have
been read for the first time to check current condition.
BCU to harness connectors
1Connector C0661
2Connector C0662
3Connector C0663
4Connector C0660
5Connector C0664

BODY CONTROL UNIT
86-3-8 DESCRIPTION AND OPERATION
C0664 connector pin details
IDM inputs
The IDM inputs are communicated to the BCU using the serial datalink so that the BCU can perform the necessary
logic operations:
The V
in for IDM digital signals are defined as follows:
lLogic 1 when V
in ≥ 8V.
lLogic 0 when V
in ≤ 2V.
IDM input voltages between 2 and 8 volts are indeterminate and cannot be guaranteed.
Pin No. Description Input/Output
1 Front left window down Output
2 Front right window down Output
3 Fuel flap release Output
4 Front left window up Output
5Earth-
6 Front right window up Output
7 Battery power supply Input
Description Signal type System
Inertia switch Digital Locking/ Unlocking/ Alarm
Side lamps Digital Exterior lighting
Headlamp dipped beam Digital Exterior lighting
Headlamp main beam daylight running lamps Analogue Exterior lighting
RH direction indicators current sense Analogue Direction indicators/ Hazards/ Alarm
LH direction indicators current sense Analogue Direction indicators/ Hazards/ Alarm
Front wiper park sense Digital Wipers and washers

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-9
IDM outputs
The IDM receives the following signals from the BCU using the serial datalink to provide power outputs:
Description Signal type System
Unlock all doors enable Digital Locking/ Unlocking/ Alarm
Lock passenger and rear doors enable Digital Locking/ Unlocking/ Alarm
Superlock all doors enable Digital Locking/ Unlocking/ Alarm
Lock driver's door Digital Locking/ Unlocking/ Alarm
Rear fog lamps enable Digital Exterior lighting
Daylight running lamps enable Digital Exterior lighting
LH direction indicators enable Digital Direction indicators/ Hazard warning/ Alarm
RH direction indicators enable Digital Direction indicators/ Hazard warning/ Alarm
Gear position indicator illumination Digital Illumination
Headlamp main beam indicator disable Digital Illumination
Front wiper enable Digital Wipers and washers
Rear wiper enable Digital Wipers and washers
Rear window enable Digital Power windows
Shift lever solenoid enable Digital Automatic gearbox
Transfer box solenoid enable/ Alarm sounder
relayDigital Gearbox
Heated rear window enable Digital Heated screens

BODY CONTROL UNIT
86-3-12 DESCRIPTION AND OPERATION
Seatbelt warning lamp Timed The warning lamp is on for 6 seconds after the ignition is turned
on.
Buckle The warning lamp is on for 6 seconds after ignition is turned on or
until the buckle is fastened.
Ignition II If the buckle is unfastened when the ignition is turned on then the
warning lamp comes on for 6 seconds.
Disable The warning lamp is not used.
Seatbelt audible warning Timed The audible warning is on for 6 seconds after the ignition is turned
on.
Buckle The audible warning is on for 6 seconds after the ignition is turned
on or until the buckle is fastened.
Ignition II If the buckle is unfastened when the ignition is turned on then the
audible warning is on for 6 seconds.
Disable The audible warning is not used.
Bulb failure warning Disabled Direction indicator bulb failure detection is disabled.
Enabled Direction indicator bulb failure detection is enabled.
Superlocking None Superlocking is not available.
Double The vehicle will superlock on a double press of the remote
transmitter or double key turn.
Single The vehicle will superlock on a single press of the remote
transmitter or a single key turn.
No key The vehicle will superlock on a single press of the remote
transmitter but not with the key.
Door unlocking Not SPE The SPE (Single Point Entry) function is not used. All doors unlock
on a remote transmitter press.
SPE Only the driver's door unlocks on the first remote transmitter press,
all other doors on the second press.
Alarm disarming Always Operation of the key in the driver's door always disarms the
vehicle.
Key only Operation of the key in the driver's door only disarms the vehicle
if it was locked with the key.
Key never The security system is not disarmed by the key (except for EKA).
Inertia switch No hazards Operation of the inertia switch does not operate the hazard
warning lamps.
Hazards Operation of the inertia switch operates the hazard warning lamps.
Speed locking Disabled Speed related locking is disabled.
Enabled Speed related locking is enabled. The door locks are disabled
when the vehicle is moving.
Volumetric sensing Disabled Volumetric sensing is disabled.
Enabled Volumetric sensing is enabled.
Alarm Disabled The vehicle is not fitted with a security system.
Enabled The vehicle is fitted with a security system.
Passive immobilisation Disabled Passive immobilisation is disabled.
Enabled Passive immobilisation is enabled.
Hazard warning lamps Disabled The hazard warning lamps do not flash on security system arm,
disarm or trigger.
Enabled The hazard warning lamps flash on security system trigger only.
All The hazards flash on security system arm, disarm and trigger.
Mislocking audible
warningDisabled Mislock audible warnings are disabled.
Enabled Mislock audible warnings are enabled. Function Option Details