four wheel drive LAND ROVER DISCOVERY 2002 User Guide

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-15
The BCU controls the wiper motor frequency of operation via the IDM when intermittent wipe or wash is selected. The
front intermittent wipe option features five different intermittent delay periods. The shortest delay period is 3 seconds
and this is increased by 2 second increments up to a maximum delay of 11 seconds. The desired delay period for the
front wipers is set by the position of the rotary switch located on the wiper column stalk.
The rear wiper switch is located on the instrument pack cowl and is latched when pressed. The rear wiper electric
motor is located in the tail door. The rear wiper operation is controlled according to a programmed strategy via the
BCU and the IDM. The BCU also checks for a signal from either the reverse lamp switch located in the vehicle gearbox
(manual gearbox models) or the gear position switch (automatic gearbox models) for operating the rear wipers when
the vehicle is in reverse. The rear wiper and washer only operate when the ignition switch is in position II.
The front and rear washer pumps and the headlamp powerwash (where fitted) are also controlled through the BCU.
The washers are operated from electric pumps attached to the washer reservoir located in the left hand wheel arch.
The front wash switch is located on the wiper column stalk and is pulled towards the steering wheel to select the
washer function. When the front washers are operated, the wipers are also activated for three full cycles. The rear
wash switch is located on the instrument pack cowl. The BCU programme can be configured in one of two modes of
operation:
lNo wiper operation when the wash switch is pressed.
lWiper action after an initial delay of 400 ms.
Headlamp wash is activated by the BCU via the IDM and operates when the headlamps are on and the front washers
function is selected.
Electric seats
The BCU controls the logical operation of the electrically operated front seats. Two modes of operation are available:

+ SEATS, DESCRIPTION AND OPERATION, Description - electric seats.
lElectric seat adjustment is enabled if the ignition is on or the driver's door is opened for a short time period.
lElectric seat adjustment is enabled if the ignition is on and the driver's door is closed.
The seats are operated by four electric motors which control the seat cushion rear up/ down, the seat cushion front
up/ down, seat cushion forward/ rearward and seat squab recline. The electrically powered lumbar adjustment in each
seat is operated by a single motorised air pump and a solenoid located on the seat squab frame. The air pump inflates
a cushion in the seat squab and the solenoid operates a valve to deflate the cushion. The seat squab and cushion
may also contain heater elements to provide heated seat operation.
The switches for electrically operated seats are located either side of the centre console.
Direction indicators and hazard warning lamps
The direction indicator lamps are operated from a three position direction indicator switch on the left hand, steering
column stalk. The BCU only allows the lamps to work as direction indicators when the ignition switch is in position II.
The BCU also controls the lamps to operate as hazard warning lamps and as a visual warning for the anti-theft system,
in which cases all lamps flash simultaneously irrespective of the ignition switch position.
System control of the direction indicators and hazard warning lamps is provided by the BCU operating with the IDM
and two electronic relays located in the passenger compartment fuse box. The IDM and relays are integral parts of
the passenger compartment fuse box and cannot be serviced individually. The serial data bus is used for
communication of status and operation requests between the BCU, IDM and instrument pack.
The hazard warning lamps are operated from a latching pushbutton switch located on the fascia.
All direction indicator/ hazard warning lamp bulbs are rated at 5 Watts.

IN CAR ENTERTAINMENT
86-6-4 DESCRIPTION AND OPERATION
Description
General
The in car entertainment (ICE) system allows the driver and passengers to listen to audio output from the speakers
or optional headphones inside the vehicle. Buttons or knobs on the radio cassette allow changes of levels or
selections during the various modes of operation. The system can be controlled from the fascia mounted radio
cassette, or optional remote control switches on the left hand side of the steering wheel. High line systems may also
have rear headphone amplifiers that have some control of the system via the radio cassette player.
One or two amplified aerials located in the rear side windows send radio signals to the radio cassette player. On high
line systems a power amplifier and a CD-autochanger may be located under the front seats. Speakers are located in
the lower door panels, additional speakers may be located in upper door trim, the A-post and the tail door. A display
screen shows the user the current system status.
The ICE supplied varies with trim level and market. Vehicles may not have all of the speakers, amplified aerials, CD-
autochanger, rear headphone amplifiers or power amplifier.
Base system radio cassette
The base radio cassette has buttons for LD (loudness) AM, FM, EJECT (tape), Reverse, Base/Balance, treble, MAN
forward and reverse. The base radio cassette is located in the center of the fascia and contains the radio and tape
player, four clips (accessible through holes in the front of the unit) secure the unit in the fascia. To remove the unit
the four clips must be released with a special tool. The base system can be controlled from the fascia mounted radio
cassette. A logic control circuit in the radio cassette player controls the operation in the various control modes.
The radio cassette has a display screen, the information shown can be the current radio frequency, tape operating,
bass or loudness settings. Power for the illumination on the radio cassette is supplied from the passenger
compartment fuse box. A main fuse is also located in the connector socket area on the back of the radio cassette.
Security code function
A combination of buttons on the radio cassette are used to input and change security codes. Security codes make the
unit unusable if the unit is disconnected from the vehicle without deactivating the security code. The radio cassette
has an internal memory chip that stores the code information, if the power is removed from the unit the chip will
activate the security code feature. For this reason the security code feature must be deactivated before the unit is
removed or the vehicles battery is disconnected.
Audio functions
The radio cassette has buttons for the following audio functions: LD (loudness), bass/balance, fader, treble and
volume.
Cassette functions
The radio cassette has buttons for the following cassette functions: eject, forward, reverse and tape reversal.
Multi function buttons
The function of presets 1-6 and the MAN button depends on current mode of operation and allows selection of radio
band, radio on, tape track and search/seek functions. The MAN button is mode dependent, when pressed the button
allows manual operation or alternate mode selections such as manual tuning.
Internal memory
An internal memory chip stores the station presets and security code, power is supplied internally to the chip via a
permanent power feed, supplied from the passenger compartment fuse box.

IN CAR ENTERTAINMENT
86-6-10 DESCRIPTION AND OPERATION
Remote radio steering wheel controls (midline and high line systems)
The remote radio control switch is located on the LH side of the steering wheel and is secured with two screws. The
wiring from the remote radio control switch plugs in to a connector that is part of the steering wheel rotary coupler.
Operation of the remote radio control switches allow the driver to control the ICE without releasing the steering wheel.
Volume, mode and selection functions can be carried out using the steering wheel mounted control switches. Control
inputs from the remote radio control switches are sent to the radio cassette player.
Aerial
On base and midline ICE systems an AM/FM aerial is built-in to the side window glass on the RH side of the vehicle.
An amplifier is located on the frame above the rear side widow behind the rear quarter trim, and is secured (and
earthed) with one bolt. Coaxial leads connect the aerial to the aerial amplifier and radio cassette. Power is supplied
from the auxilary relay in the engine compartment fuse box, through a fuse in the passenger compartment fusebox to
the amplifier.
On high line ICE systems two amplified aerials are built-in to the side window glass of the vehicle. The two aerials are
an AM/FM aerial on the RH side, and an FM aerial on the LH side. The amplifier for each aerial are located on the
frame above each rear side widow behind the rear quarter trim, and are each secured (and earthed) with one bolt.
Amplified aerials improve the reception quality, the FM aerial gives improved reception in areas of poor signal
(diversity) conditions in urban areas. A Power feed from the radio cassette player is connected to the amplified aerials,
power is available when the cassette player is operating. The aerials are connected to the radio cassette player by
two coaxial cables, a small plug connects the FM only aerial, a larger plug connects the AM/FM aerial.
Power amplifier (high line system)
The amplifier is located on a bracket under the LH front seat and is secured with three screws and washers. The
amplifier receives inputs from the radio, radio cassette player or (via the radio cassette player) the CD-autochanger.
Power for the amplifier is supplied from the passenger compartment fuse box. The amplifier will power up when an
enable logic signal is sent from the radio cassette, this signal is sent by the radio cassette when it is turned on.
CD-autochanger (high line system)
A CD-autochanger is located under the RH front seat, the unit is secured to brackets in the floor with four screws and
washers. A tray is used to hold each compact disk (CD), the loaded tray is then inserted in a magazine, the magazine
holds six trays and is then inserted into the CD-autochanger. A sliding cover protects the internal components of the
CD-autochanger from dirt entry through the magazine opening. An eject button located on the front of the CD-
autochanger can be used to release the magazine from the CD-autochanger. The sliding cover has to be opened
manually before the magazine eject button is pressed. The operation of the CD-autochanger is controlled by inputs
from the radio cassette, the control inputs can be from the radio cassette buttons, the remote radio controls or the rear
radio headphone amplifiers if they are fitted. The output from the CD-autochanger are connected to the radio cassette
player. The radio cassette player sends the outputs to the power amplifier. Power is supplied to the CD-autochanger
by a feed from the radio cassette player.
Radio headphone amplifiers (high line system)
The rear mounted radio headphone amplifiers are located in the lower rear quarter trim casing and are held in position
by a clip on the side of the headphone amplifier. Mode and function buttons are located on a control panel, the mode
button allows each of the rear seat passengers to independently select from the radio, tape or CD-autochanger. The
driver and the rear seat passengers can each listen to any of the audio devices they select. However the radio
cassette setting has overall priority e.g:
lIf the radio cassette is using a radio wave band (AM or FM), the headphone user will be able to select the cassette
tracks or CD-autochanger. The user will be able to listen to same radio band that is selected on the radio
cassette, but will not be able to change the station selected.
lIf the radio cassette has CD-autochanger selected, the headphone amplifiers will allow listening to the compact
disk but will not allow track changes. The headphone user will be able to select on all of the radio bands or
cassette tracks.
lIf the radio cassette has tape selected, the headphone amplifiers will allow listening to the tape but will not allow
track changes. The headphone user will be able to select all radio bands or CD's on the CD-autochanger.