1999 LAND ROVER DISCOVERY fuse box

WINDOWS
86-5-4 DESCRIPTION AND OPERATION
Description
Body Control Unit (BCU)
RHD shown, LHD similar
The BCU controls all operations for the front windows. It controls the voltage and the earth paths to the window
motors, it controls one-touch down operation and it detects stall conditions. Stall detection protects the system from
sustained high current draw that occurs when a window reaches the fully up/down position or becomes stuck. When
the BCU detects a stall condition, it disables operation at the stalled window until the window switch is released. Upon
releasing the window switch, the BCU allows normal window operation.
The BCU receives power from fuse 34 (30A) of the passenger compartment fusebox. There is a unique earth signal
between each pole of the front window switches and the BCU. This allows the BCU to determine which window motor
to operate as well as which direction to operate the motor. The BCU operates the front window motors directly. There
are no relays or switches between the BCU and the window motors.
The BCU disables stall detection on the front windows for a period of 500 ms when an electric window operates to
allow for initial current surge to the window motor. After this period, if the BCU detects a stall signal (high current draw)
for more than 300 ms, it disables the window motor until the window switch is released.
The BCU also contains the ignition switched off timeout information for both the front and the rear windows. It controls
the rear window timeout function through the IDM.
TestBook communicates with the BCU and can determine the status of the front window switches. TestBook can also
operate both front windows. TestBook can only determine rear window timeout status. It cannot determine the status
of the rear windows, nor can it operate the rear windows.
Do not feed TestBook cables through open windows as the windows operate while performing test.

WINDOWS
DESCRIPTION AND OPERATION 86-5-7
Rear window lift relay
The rear window lift relay is a normally open relay that provides power to the rear window system. It is controlled by
the IDM. The IDM receives a rear window enable signal from the BCU to allow operation during the ignition switched-
off timeout period.
Both the rear window lift relay and the IDM are located in the passenger compartment fusebox. The IDM is integral
to the passenger compartment fusebox.
The rear window lift relay receives voltage from fuse 13 (30A) in the passenger compartment fusebox. The IDM
controls the earth side of the relay coil.
TestBook cannot monitor the status of the rear window lift relay.

WINDOWS
86-5-8 DESCRIPTION AND OPERATION
Rear window switches
There are two sets of switches that operate the rear windows. There is a set of rear window switches located in the
centre console that allow the front seat occupants to operate the rear windows. The second set of switches are
located on the rear doors. All rear window switches are non-latching rocker switches.
A conventional window switch circuit controls the rear window system. In the rest position, there is battery voltage at
both sides of every switch as well as at the window motors. Operating any switch provides a ground path through the
switch to the window motor. Operating the switch in the opposite direction switches the voltage path and the earth
path to the motor allowing the motor to run in the opposite direction.
Voltage for the rear windows is from fuse 13 (30A) in the passenger compartment fusebox through the rear window
lift relay to the switches and motors.
TestBook cannot monitor the status of the rear window switches.

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
86-6-6 DESCRIPTION AND OPERATION
Midline system radio cassette
The midline 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. To remove the radio cassette unit the four clips
must be released with a special tool. The midline system can be controlled from the fascia mounted radio cassette,
or from remote radio control switches on the left hand side of the steering wheel. The audio signal can be from the
radio, cassette player or a optional CD-autochanger. A logic control circuit in the radio cassette player controls the
operation in the various control modes.
The radio cassette has a display screen, information shown can include current status, station (radio mode) or
cassette tape track or (optional) CD-autochanger track/disc status. Power for illumination on the radio cassette is
supplied from the passenger compartment fusebox. 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 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
A rotary knob allows changes of levels or selections during the various modes of operation, this includes volume,
bass, treble and fader.
Cassette functions
The radio cassette has buttons for the following cassette functions eject, tape, reverse, forward, tape eject/reversal.
Radio functions
The radio cassette has buttons for the selection of AM or FM reception. Selection of the radio station is controlled by
the use of the multi-function buttons on the radio cassette player, the radio headphone amplifiers or the remote radio
controls on the steering wheel.
Traffic information and news function
A traffic information button (TA/NEWS) allows traffic or news information to be selected on the FM waveband only, in
this mode the audio output will mute when traffic or news messages are received. After the traffic or news message
the radio, cassette tape or CD will resume play, the traffic and news information varies with the country of use and
radio band selected.
C0922 (high line systems)
7 Radio headphone active Input
8 I-BUS communications Input/Output
9 Audio amplifier spatial imaging enable Output
10 Radio headphone LH remote control Input
11 Radio headphone RH remote control Input
12 Headphone remote controls feed Output
C1354 (high line systems)
13 CD-autochanger audio left channel Input +
14 CD-autochanger audio right channel Input +
15 CD-autochanger audio earth Output
16 CD-autochanger audio left channel Input -
17 CD-autochanger audio right channel Input -
18 Not Used
19 CD-autochanger I-BUS communications link Input/Output
20 CD-autochanger permanent feed Output

IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-7
Multi function buttons
Rotary controls are located on the front of the radio cassette for adjustment of bass, treble etc, depending on current
mode selected. Operation of presets 1-6 depends on current mode of operation and allows selection of radio band
(Radio mode on) or CD-autochanger disc (in the CD mode). Scan (Mode dependent) manual or automatic selection
of band or track. RND random play, MODE/MUTE (mode dependent) when pressed the button allows manual
operation or alternate mode selections such as manual tuning, compact disk cue/review, tape forward/rewind modes.
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.
High line system radio cassette
The high line radio cassette is located in the center of the fascia and contains the radio and tape player. Two clips
(accessible through slots in the front of the unit) secure the unit. To remove the radio cassette unit the two clips must
be released with a special tool. The high line system can be controlled from the fascia mounted radio cassette, or from
remote radio control switches on the left hand side of the steering wheel. In vehicles fitted with radio headphone
amplifiers, the rear seat passengers can control their individual audio output using a headphone amplifier control
panel. The audio signal can be from the radio, cassette player or a CD-autochanger. A logic control circuit in the radio
cassette player controls the operation in the various control modes.
The radio cassette has a display screen, information shown includes current status, station (Radio mode) , CD-
autochanger track/disc status or status of headphone amplifier. Power for illumination on the radio cassette is supplied
from the passenger compartment fusebox. A main fuse is also located in the connector socket area on the back of
the radio cassette. When the radio cassette switch is on, power is made available via internal circuits to the radio
headphone amplifiers.
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 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
A rotary knob allows changes of levels or selections during the various modes of operation, this includes volume,
bass, treble, fader and spatial on/off.
Cassette functions
The radio cassette has buttons for the following cassette functions; eject, fast forward, rewind and dolby. The dolby
symbol is shown on the dot matrix display screen if dolby mode is selected.
Radio functions
The radio cassette has buttons for the selection of AM or FM reception. Selection of the radio station is controlled by
the use of the multi-function buttons on the radio cassette player, the radio headphone amplifiers or the remote radio
controls on the steering wheel.
CD-autochanger functions
The CD button on the radio cassette player allows selection of the CD-autochanger. CD disc and track selection is
controlled by the use of the multi-function buttons on the radio cassette player, the radio headphone amplifiers or the
remote radio controls on the steering wheel.
Traffic information function
A traffic/news information button (I) allows traffic or news information to be selected on the FM waveband only, in this
mode the radio will mute when traffic or news messages are received. After the traffic or news message the radio,
cassette tape or CD will resume play, the traffic and news information varies with the country of use and radio band
selected.

IN CAR ENTERTAINMENT
86-6-8 DESCRIPTION AND OPERATION
Multi function buttons
The music symbol button is used for mode selection for adjustment of bass, treble etc. depending on current mode
selected. Operation of presets 1-6 depends on current mode of operation and allows selection of radio band (Radio
mode on) or CD-autochanger disc (in the CD mode). Search/Seek (Mode dependent) manual or automatic selection
of band or track. MAN (mode dependent) when pressed the button allows manual operation or alternate mode
selections such as manual tuning, compact disk cue/review, tape forward/rewind modes. The mode dependent SCAN
button allows automatic searching of radio bands, tape or compact disk tracks.
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.
Radio cassette player connector pin details.
Connector/Pin
No.Description Input/Output
C0092
1 Rear RH speaker line Output +
2 Rear RH speaker line Output -
3 Front RH speaker line Output +
4 Front RH speaker line Output -
5 Front LH speaker line Output +
6 Front LH speaker line Output -
7 Rear LH speaker line Output +
8 Rear LH speaker line Output -

IN CAR ENTERTAINMENT
86-6-10 DESCRIPTION AND OPERATION
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.
If one headphone amplifier unit has control of the tape player, CD or radio, the other headphone amplifier will be able
to listen and be able to change tape tracks or radio bands. Other buttons allow a search seek function of radio band
or compact disk track, reversal of the tape, radio station and volume adjustment depending on the current operating
mode. If one radio headphone amplifier has control of the radio, tape or CD autochanger the other radio headphone
amplifier is able to change the track or radio band selected. A headphone socket with a glow ring is located on the
control panel. When a headphone is turned on , a 'headphone-module active' signal is sent to the radio cassette
player. The design incorporates panel illumination and a glow-ring to locate the socket in low light conditions. To
control the audio output from the radio headphone amplifiers, signals are sent to and received from the radio cassette
player.