2002 LAND ROVER DISCOVERY warning

BODY CONTROL UNIT
86-3-32 DESCRIPTION AND OPERATION
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.
Gear position indicator illumination
On automatic gearbox models, two variations of illumination for the gear position indicators on the selector lever can
be programmed into the BCU. In option 1, illumination is provided when the ignition is on. In option 2, illumination is
enabled when the ignition is on and the side lamps are off.
Starter relay
The BCU checks the status of the following inputs and internal BCU conditions to determine whether or not to provide
an output to enable the starter relay:
lAutostart inhibit (vehicles with automatic gearbox only).
lSecurity start inhibit (immobilisation check).
lEngine running (link to instrument pack).
lEEPROM locked (internal check).
lIDM and BCU matched.
When the BCU receives a crank signal from the ignition switch, an earth path is completed to the starter relay coil,
provided that the security system has been de-activated. If the ECM has not received a valid unlock/ remobilise signal,
the starter relay will be disengaged and the engine stopped. The BCU also receives an engine running signal from
the instrument pack, so that if the ignition key is turned to the crank position while the engine is running, the starter
motor relay will not be engaged.
If the logic conditions are correct to allow starter operation, the completion of the earth path from the starter relay coil
to the BCU energises the coil and the relay contacts close to supply battery power to the starter motor.
When the ignition switch is released from the crank position, the power supply feed from the ignition switch to the
starter relay coil is interrupted and the relay contacts open to prevent further battery feed to the starter motor.
If a communications link failure is experienced, the BCU will be prevented from detecting the 'engine running'
condition and the BCU will default to assume that the engine is not running.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-35
Fuel flap release
The fuel flap release solenoid only operates when the ignition switch is switched off, the anti-theft system is not
activated and the fuel flap release switch is pressed. If the BCU detects that these conditions have been satisfied, it
provides a path to earth for the fuel flap solenoid, so allowing the fuel flap to be opened.
To decide the correct conditions for providing a fuel flap enable output, the BCU checks the following input conditions:
lIgnition state.
lPerimetric alarm state.
If the battery state is not normal, the electric fuel flap enable is switched off.
Audible warnings
The BCU can request the instrument pack to generate an audible warning in response to logic conditions which have
been detected by the BCU and which need to be drawn to the driver's attention.

+ INSTRUMENTS, DESCRIPTION AND OPERATION, Description.
Seat belt warning
The BCU can be programmed to include seat belt warning using one of four options:
lOption 1 – warning on for 6 seconds.
lOption 2 – warning on for 6 seconds or until the seat belt is fastened.
lOption 3 – warning on for 6 seconds unless the seat belt is fastened.
lOption 4 – no warning.
The BCU checks the status of the following inputs:
lIgnition on.
lSeat belt fastened.
Depending on the logic conditions of the inputs, the BCU provides the following outputs:
lAudible warning No.1 requested.
lSeat belt not fastened warning on instrument pack (via datalink to the instrument pack).
When programmed for option 1 operation, audible warning No. 1 is requested when the ignition switch is turned from
off to position II. The audible warning remains active for 6 seconds and a warning lamp on the instrument pack is
illuminated for the same duration.
When programmed for option 2 operation, audible warning No. 1 is requested when the ignition switch is turned from
off to position II. The audible warning remains active for 6 seconds or until the seat belt fastened signal is on and a
warning lamp on the instrument pack is illuminated for the same duration.
When programmed for option 3 operation, audible warning No. 1 is requested when the ignition switch is turned from
off to position II. The audible warning remains active for 6 seconds if the seat belt fastened signal is off; a warning
lamp on the instrument pack is illuminated for the same duration.
In the event of a communications link failure occurring, the audible and visual warning requests are not sent to the
instrument pack.

BODY CONTROL UNIT
86-3-36 DESCRIPTION AND OPERATION
Key-in warning
The BCU can be programmed to one of two options:
lOption 1 – no timeout.
lOption 2 – no key-in warning.
The BCU issues an audible warning No. 2 request, depending on the status of the following inputs:
lIgnition state.
lIgnition key inserted.
lDriver's door open.
If the key-in warning is programmed into the BCU for operation, audible warning No.2 will be requested if the ignition
switch is off, the ignition key inserted signal is on and the driver's door open signal is ON.
In the event of a communications link failure occurring, the audible warning request is not sent to the instrument pack.
SLABS HDC warning
The BCU issues an audible warning No. 3 request, depending on the status of the following inputs:
lIgnition state.
lSLABS HDC warning.
The SLABS warning transmitted by the SLABS ECU is a 2 Hz signal, audible warning No. 3 is requested on every
falling edge of this signal. If the signal from the SLABS ECU stays low for more than 650 ms, audible warning No. 3
is requested every 2 seconds, for 30 seconds, while the signal stays low.
In the event of a communications link failure occurring, the audible warning request is not sent to the instrument pack.
Transfer box in neutral warning
If the transfer box is in the neutral position and the ignition switch is on, the BCU issues an audible warning No. 4
request. The BCU checks for the following inputs:
lTransfer box neutral selected.
lIgnition on.
The transfer box in neutral warning is activated by communicating with the instrument pack via the serial datalink. If
a communications link failure occurs while the transfer box in neutral warning is active, the audible warning will not
operate.
Lights on warning
If the ignition switch is off while the side lamps or headlamps on and the driver's door is opened, the BCU issues an
audible warning No. 5 request.
The BCU checks for the following inputs:
lDriver's door open.
lIgnition on.
lSide lamps.
lDipped beam state.
lMain beam state.
The lights on warning is activated by communicating with the instrument pack via the serial datalink. If a
communications link failure occurs while the lights on warning is active, the audible warning will not operate.

ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION 86-4-13
Battery Backed-up Sounder (BBUS)
The BBUS is located behind the rear quarter trim panel on the right hand side of the vehicle and is utilised as an
additional alarm warning device. It has a self contained power source allowing it to operate when the vehicle battery
is disconnected.
NOTE: Always disarm the BBUS before carrying out any procedures related to the BBUS.
Input/Output
The BBUS utilises a 12 volts power supply from fuse 20 (15 amperes) located in the passenger compartment fusebox
via a relay to charge the self contained battery.
When the alarm is triggered, the BCU is pulled high internally triggering the BBUS to sound continuously for 30
seconds.
The BCU sets the BBUS to its internal battery backed mode when the vehicle battery is disconnected.
If a mislock occurs the BCU triggers the BBUS for a period of 50 ms.
The BCU triggers the BBUS once for a period of 50 ms when an EKA code is requested.
When the EKA code is entered correctly, the BBUS will operate twice for a period of 50 ms on, 200 ms off.
The BBUS utilises a dedicated earth path.

ALARM SYSTEM AND HORN
86-4-14 DESCRIPTION AND OPERATION
Vehicle horn/alarm sounder
Vehicle horn
Alarm sounder
Depending on system configuration, the alarm sounder will either sound independently or in conjunction with the
vehicle horns as an alarm triggered warning. The alarm sounder is located under the bonnet on the bulkhead. If the
alarm is triggered, the alarm sounder operates at 0.5 second intervals in phase with the direction indicators.
Input/Output
The BCU provides an earth path for the alarm sounder relay situated in the passenger compartment fuse box.
Fuse 21 supplies battery power to the alarm sounder relay. When an unauthorised entry to the vehicle is detected,
the BCU provides an earth path for the alarm sounder relay. This earth path energises the alarm sounder relay, which
activates the alarm sounder.
If a mislock occurs the BCU triggers the alarm sounder 2 times for a period of 50 ms on, 200 ms off.
The BCU triggers the alarm sounder once for a period of 50 ms when an EKA code is requested.
When the EKA code is entered correctly, the alarm sounder will operate twice for a period of 50 ms on, 200 ms off.
The alarm sounder relay has a dedicated signal to the BCU.

ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION 86-4-15
Anti-theft status LED
A Light Emitting Diode (LED) situated in the instrument cluster indicates the condition of the anti-theft system and acts
as a warning to potential thieves that the alarm system is activated.
Input/Output
The LED has a dedicated signal from the BCU to indicate the status of the following:
lAlarm armed: The LED flashes at 10 Hz with a 50:50 duty cycle for 10 seconds, after which the LED flashes 50
ms on, 2 seconds off until the state of the system changes.
lEngine immobilised: If the engine is immobilised and the ignition is on, the LED is illuminated continuously. If the
engine is immobilised and the ignition is off, the LED flashes 50 ms on, 2 seconds off.
lAlarm tampered: If the alarm has been triggered, the LED flashes at 10 Hz with a 50:50 duty cycle.
lHandset battery low indicator: If the handset battery is low, the driver's door is open and the ignition is switched
off, the LED flashes two pulses of 50 ms on, 50 ms off, every 10 seconds.

ALARM SYSTEM AND HORN
86-4-16 DESCRIPTION AND OPERATION
Operation
Standard system functions
All vehicles have the following functions as standard.
lLocking.
lUnlocking.
lFuel cut off switch unlocking.
lInternal locking.
lElectric fuel flap release.
Locking
The doors are locked by pressing the lock button on the handset or by locking the vehicle from the driver's door with
the key.
In order to lock the vehicle, the following conditions must be met:
lThe driver's door is closed.
lThe ignition is off.
lThe fuel cut off switch is not tripped.
lThe bonnet is closed.
lThe vehicle is not super locked.
Depending on system configuration a mislock occurs if these conditions are not met. The doors may lock (depending
on condition not met) and the system may not fully arm, depending on configuration of the system. If a mislock occurs
an audible warning is emitted and the vehicle becomes partially armed.
Unlocking
The doors are unlocked by pressing the unlock button on the handset or by unlocking the vehicle from the driver's
door with the key. This may unlock only the driver's door or it may unlock all doors depending on system configuration.
Fuel cut off switch unlocking
In the event that the vehicle experiences a force strong enough to actuate the switch, all the doors on the vehicle
immediately unlock. The following conditions must be met for this to occur:
lThe security system is not armed.
lThe ignition is on.
This same action causes the fuel pump to shut off and disables the Engine Control Module (ECM). In some markets,
this action may also cause the direction indicators lights to flash.

ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION 86-4-17
Internal locking
Internal locking allows the doors to be locked / unlocked from a central position using switches on the instrument
panel. The internal unlock switch will not operate if the vehicle is super locked.
Electric fuel flap release
Up to 03 model year shown
The fuel flap is opened by pressing the button on the fascia on vehicles up to 03 model year or on the instrument pack
binacle on vehicles from 03 model year. This works only if the anti-theft system is not armed and the ignition is off.
In some configurations, it may also be necessary to remove the key from the ignition switch.
Configurable system functions
The following alarm system features are configurable using TestBook.
lPerimetric alarm.
lVolumetric alarm.
lSuper locking.
lPartial arming.
lMislock.
lPassive immobilisation.
lPassive remobilisation.
lEmergency key access.
lSingle point entry.
lSpeed related locking.
lAcclimatisation related locking.
lVisual warnings.
lAudible warning.
lTheft deterrent led.
lTransit mode.