2002 LAND ROVER DISCOVERY CD changer

HEATING AND VENTILATION
80-12DESCRIPTION AND OPERATION
Circulation pump. The circulation pump is installed at the coolant inlet to the FBH unit to assist the coolant flow through
the FBH unit and the heater assembly. The pump runs continuously while the FBH unit is in standby or active
operating modes. While the FBH unit is inactive, coolant flow is reliant on the engine coolant pump.
Combustion air fan. The combustion air fan regulates the flow of air into the unit to support combustion of the fuel
supplied by the FBH pump. It also supplies the air required to purge and cool the FBH unit. Ambient air is supplied to
the combustion air fan through an air inlet hose containing a sound deadening foam ring.
Burner housing. The burner housing contains the burner insert and also incorporates connections for the exhaust
pipe, the coolant inlet from the circulation pump and the coolant outlet to the heater assembly. The exhaust pipe
directs exhaust combustion gases to atmosphere at the bottom of the engine compartment.
The burner insert incorporates the fuel combustion chamber, an evaporator and a glow plug/flame sensor. Fuel from
the FBH fuel pump is supplied to the evaporator, where it evaporates and enters the combustion chamber to mix with
air from the combustion air fan. The glow plug/flame sensor provides the ignition source of the fuel:air mixture and,
once combustion is established, monitors the flame.
ECU/heat exchanger. The ECU controls and monitors operation of the FBH system. Ventilation of the ECU is
provided by an internal flow of air from the combustion air fan. The heat exchanger transfers heat generated by
combustion to the coolant. A sensor in the heat exchanger provides the ECU with an input of heat exchanger casing
temperature, which the ECU relates to coolant temperature and uses to control system operation. The temperature
settings in the ECU are calibrated to compensate for the difference between coolant temperature and the heat
exchanger casing temperature detected by the sensor. Typically: as the coolant temperature increases, the coolant
will be approximately 7
°C (12.6 °F) hotter than the temperature detected by the sensor; as the coolant temperature
decreases, the coolant will be approximately 2
°C (3.6 °F) cooler than the temperature detected by the sensor.

HEATING AND VENTILATION
DESCRIPTION AND OPERATION 80-13
Operation
Air distribution
Turning the distribution knob on the control panel turns the control flaps in the heater assembly to direct air to the
corresponding fascia and footwell outlets.
Air temperature
Turning the LH or RH temperature knob on the control panel turns the related blend flaps in the heater assembly. The
blend flaps vary the proportion of air going through the cold air bypass and the heater matrix. The proportion varies,
between full bypass no heat and no bypass full heat, to correspond with the position of the temperature knob.
Blower speed
The blower can be selected off or to run at one of four speeds. While the ignition is on, when the blower switch is set
to positions 1, 2, 3, or 4, ignition power energises the blower relay, which supplies battery power to the blower. At
switch positions 1, 2 and 3, the blower switch also connects the blower to different earth paths through the resistor
pack, to produce corresponding differences of blower operating voltage and speed. At position 4, the blower switch
connects an earth direct to the blower, bypassing the resistor pack, and full battery voltage drives the blower at
maximum speed.
Fresh/Recirculated inlet air
When the recirculated air switch is latched in, the amber indicator LED in the switch illuminates and an earth is
connected to the recirculated air side of the fresh/recirculated air servo motor. The fresh/recirculated air servo motor
then turns the control flaps in the air inlet duct to close the fresh air inlet and open the recirculated air inlets.
When the latch of the recirculated air switch is released, the amber indicator LED in the switch extinguishes and the
earth is switched from the recirculated air side to the fresh air side of the fresh/recirculated air servo motor. The fresh/
recirculated air servo motor then turns the control flaps in the air inlet duct to open the fresh air inlet and close the
recirculated air inlets.
FBH system (where fitted)
The FBH system operates only while the engine is running and the ambient temperature is less than 5
°C (41 °F).
With the engine running and the ambient temperature below 5
°C (41 °F), the air temperature sensor connects the
alternator power supply to the ECU in the FBH unit. On receipt of the alternator power supply, the ECU starts the
circulation pump and, depending on the input from the temperature sensor in the heat exchanger, enters either a
standby or active mode of operation. If the heat exchanger casing temperature is 65
°C (149 °F) or above, the ECU
enters a standby mode of operation. If the heat exchanger casing temperature is below 65
°C (149 °F), the ECU enters
an active mode of operation. In the standby mode, the ECU monitors the heat exchanger casing temperature and
enters the active mode if it drops below 65
°C (149 °F). In the active mode, the ECU initiates a start sequence and
then operates the system at full or part load combustion to provide the required heat input to the coolant.
Start sequence
At the beginning of the start sequence the ECU energises the glow plug function of the glow plug/flame sensor, to
preheat the combustion chamber, and starts the combustion air fan at slow speed. After 30 seconds, the ECU
energises the FBH fuel pump at the starting sequence speed. The fuel delivered by the FBH fuel pump evaporates in
the combustion chamber, mixes with air from the combustion air fan and is ignited by the glow plug/flame sensor. The
ECU then progressively increases the speed of the FBH fuel pump and the combustion air fan to either part or full
load speed, as required by the system. Once full or part load speed is achieved, the ECU switches the glow plug/flame
sensor from the glow plug function to the flame sensing function to monitor combustion. From the beginning of the
start sequence to stable combustion takes approximately 90 seconds for a start to part load combustion and 150
seconds for a start to full load combustion.

HEATING AND VENTILATION
80-14DESCRIPTION AND OPERATION
Coolant temperature control
When the ECU first enters the active mode, it initiates a start to full load combustion. Full load combustion continues
until the heat exchanger casing temperature reaches 60
°C (140 °F), when the ECU decreases the speed of the FBH
fuel pump and the combustion air fan to half speed, to produce part load combustion. The ECU maintains part load
combustion while the heat exchanger casing temperature remains between 54 and 65
°C (129 and 149 °F). If the heat
exchanger casing temperature decreases to 54
°C (129 °F), the ECU switches the system to full load combustion
again. If the heat exchanger casing temperature increases to 65
°C (149 °F), the ECU enters a control idle phase of
operation.
On entering the control idle phase, the ECU immediately switches the FBH fuel pump off, to stop combustion, and
starts a timer for the combustion air fan. After a 2 minute cooldown period, the ECU switches the combustion air fan
off and then remains in the control idle phase while the heat exchanger casing temperature remains above 59
°C (138
°F). If the heat exchanger casing temperature decreases to 59 °C (138 °F), within 15 minutes of the ECU entering the
control idle phase, the ECU initiates a start to part load combustion. If more than 15 minutes elapse before the heat
exchanger casing temperature decreases to 59
°C (138 °F), the ECU initiates a start to full load combustion.
In order to limit the build-up of carbon deposits on the glow plug/flame sensor, the ECU also enters the control idle
phase if the continuous part and/or full load combustion time exceeds 72 minutes. After the cooldown period, if the
heat exchanger casing is still in the temperature range that requires additional heat, the ECU initiates an immediate
restart to part or full load combustion, as appropriate.
Shutdown
The FBH system is de-activated when the alternator power supply to the FBH unit is disconnected, either by the
engine stopping or, if the ambient temperature increases to 5
°C (41 °F) or above, by the contacts in the air
temperature sensor opening. If the system is active when the alternator power supply is disconnected, the ECU de-
energises the FBH fuel pump to stop combustion, but continues operation of the combustion air fan and the circulation
pump to cool down the FBH unit. The cool down time depends on the combustion load at the time the alternator power
input is disconnected.
Cool down times
Diagnostics
The ECU in the FBH unit monitors the system for faults. Any faults detected are stored in a volatile memory in the the
ECU, which can be interrogated by Testbook. A maximum of three faults and associated freeze frame data can be
stored at any one time. If a further fault is detected, the oldest fault is overwritten by the new fault.
The ECU also incorporates an error lockout mode of operation that inhibits system operation to prevent serious faults
from causing further damage to the system. In the error lockout mode, the ECU immediately stops the FBH fuel pump,
and stops the combustion air fan and circulation pump after a cool down time of approximately 2 minutes. Error lockout
occurs for start sequence failures and/or combustion flameouts, heat exchanger casing overheat and out of limit input
voltage. The error lockout mode can be cleared using Testbook, or by disconnecting the battery power supply for a
minimum of 10 seconds.
Start failure/flameout. If a start sequence fails to establish combustion, or a flameout occurs after combustion is
established, the ECU immediately initiates another start sequence. The start failure or flameout is also recorded by
an event timer in the ECU. The event timer is increased by one after each start failure or flameout, and decreased by
one if a subsequent start is successful. If the event timer increases to three (over any number of drive cycles), the
ECU enters the error lockout mode.
Heat exchanger casing overheat. To protect the system from excessive temperatures, the ECU enters the error
lockout mode if the heat exchanger casing temperature exceeds 105
°C (221 °F).
Out of limit voltage. The ECU enters the error lockout mode if the battery or alternator power input is less than 10.5
±
0.3 V for more than 20 seconds, or more than 15.5
± 0.5 V for more than 6 seconds.
Combustion load Cool down time, seconds
Part 100
Full 175

IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-1
IN CAR ENTERTA INMENT DESCRIPTION AND OPERAT ION
ICE System Component layout
High line RHD system shown (LHD system similar)
1FM aerial and amplifier (high line only)
2AM/FM aerial and amplifier
3Power amplifier (high line only)
4Radio cassette player
5Remote radio control switches (mid line and
high line only)
6Upper front door speaker LH/RH (high line
only)
7A post speaker LH/RH (mid line and high line
only)8Upper rear door speaker, LH/RH (high line
only)
9Lower front door speaker LH/RH
10CD-autochanger (if fitted)
11Lower rear door speaker LH/RH
12Radio headphone amplifier LH/RH (high line
only)
13Tail door speakers (high line only)

IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-3
High line ICE system control diagram
1Fusible link
2Battery power supply fuse
3Remote radio control switches
4Radio cassette
5CD-autochanger
6Telephone system interface
7Speed signal from SLABS ECU
8Speakers
9Power amplifier10Auxiliary power supply fuse
11Auxiliary relay
12Radio headphone amplifier RH rear
13Radio headphone amplifier LH rear
14Amplifier FM aerial
15FM aerial
16Amplifier AM/FM aerial
17AM/FM aerial

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.
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.