1999 LAND ROVER DISCOVERY brakes

CORROSION PREVENTION AND SEALING
SEALING 77-4-9
SEALING
Body Sealing
Underbody sealer treatment areas
Underfloor areas and sill outer panels are treated with a Plastisol PVC underbody sealer. This material is not suitable
for re-treatment. When repairing areas of underbody sealer, strip the factory-applied underbody sealer back to a
suitable break point. Ensure that a clean metal surface is exposed and that the edge of the existing sealer adheres
soundly to the panel.
Apply new underbody sealer between primer and surfacer paint operations. Apply seam sealer as necessary before
application of underbody sealer. Ensure that blanking plugs and grommets in the floor pan (except those used for wax
injection) are fitted before underbody sealer application. Refit any heat-fusible plugs which have been disturbed in
repair with the aid of a hot air blower, or replace with rubber grommets.
CAUTION: Ensure that suspension units, wheels, tyres, power unit, propeller shafts, exhaust and brakes
(including all mounting points) are shielded prior to application of fresh underbody sealer.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-17
The existence of an intermediate state causes a fault code to be detected by the BCU. To reduce the chances of the
fault condition occurring while changing selector lever position, the inputs are debounced and only considered valid
when they have existed for at least 33 ms.
Transmission neutral selector
The transmission neutral sensor provides an earth signal to the BCU when the transfer box is in neutral. The earth
signal causes the BCU to operate an audible warning when the transfer box is in neutral with the ignition switched on.

+ TRANSFER BOX - LT230SE, DESCRIPTION AND OPERATION, Description.
Self levelling suspension and ABS
The BCU communicates with the SLABS ECU for several functions:
lAn output is provided from the SLABS ECU to the BCU to provide the logic conditions for issuing the SLS audible
warning.
lThe BCU receives an input from the SLABS ECU relating to the raise/ lower command from the remote handset.

+ REAR SUSPENSION, DESCRIPTION AND OPERATION, Description - SLS.
Hill descent control
The BCU provides an output signal to the SLABS ECU for automatic transmission in neutral for HDC control. The
BCU checks the status of the ignition and 'gearbox state' inputs and provides a 'Neutral selected' output. If the ignition
is on and 'gearbox state' is Neutral, the 'Neutral selected' output is on, otherwise 'Neutral selected' is off.

+ BRAKES, DESCRIPTION AND OPERATION, Description.
Heated screens
The Heated Front Screen (HFS) is fitted for some market destinations and is operated from a non-latching switch
located on the instrument pack cowl. The BCU will only allow the heated front screen to operate when the engine is
running and controls the time-out period for switching the circuit off.
The heated front screen operation can also be controlled from the Automatic Temperature Control (ATC) ECU on
vehicles fitted with air conditioning.
The heated rear window will only function when the engine is running, and is operated by a non-latching switch on the
instrument pack cowl. The heated rear window can also be operated by the ATC ECU on vehicles fitted with air
conditioning.
Interior courtesy lamps
The BCU controls the operation of the interior courtesy lamps. The courtesy lamps are situated in the front, mid and
rear areas of the headlining.
Fuel flap actuator
The BCU provides an earth path to the fuel flap release solenoid to allow the fuel filler flap to be opened. This is only
allowed if the alarm system is not set and all other conditions have been satisfied. The fuel flap release switch is
located in the fascia switch pack on vehicles up to 2003 model year or in the instrument pack binacle on vehicles from
2003 model year. The switch receives a voltage supply from the passenger compartment fuse box.

IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-11
Automatic volume control (High line system only)
An automatic base and treble volume control feature compensates for increases in interior road/transmission noise.
A road speed signal is monitored by the power amplifier, the signal is supplied by the SLABS ECU.

+ BRAKES, DESCRIPTION AND OPERATION, Description.The power amplifier boosts the levels of base
and treble as road speed increases. This system ensures that the apparent volume of sound remains constant and is
not affected by increases in the background noise in the vehicle.
Speakers
Some vehicles will not have all the speakers, the type and location of speakers fitted depends on the trim level and
ICE options specified for the vehicle.
A-post speakers LH/RH (if fitted)
The A-post speakers are located in the A-post trim on each side of the windscreen, and are each protected by a metal
grille. The speakers are held from the rear by a bayonet clip that clamps the speaker on to the A-post trim. The A-post
speakers are a high range type and have a power rating of:
lMid line system A-post speakers have a power rating of 15 watts and an impedance of 4 Ω.
lHigh line system A-post speakers have a power rating of 30 watts and an impedance of 4 Ω.
Upper front and rear door speakers LH/RH (high line system only)
The upper door speakers are located in the upper door trim, the speaker is protected by an integral metal grille. The
speaker is held in by a threaded ring that clamps the speaker from the rear onto the door trim. The upper door speaker
is a mid-range type and has a power rating of 30 watts and an impedance of 4 Ω.
Lower front door speakers LH/RH
The lower front door speaker is located in the front end of the lower (pocket) trim and is secured by three self tapping
screws. The speaker is protected by a clip on circular metal grille. The type of lower front door speakers fitted depends
on trim level and market:
lThe base and mid line systems are fitted with full-range door speakers with a power rating of 15 watts and an
impedance of 4 Ω
lThe high line system is fitted with a low-range door speaker with a power rating of 30 watts and an impedance
of 4 Ω.
Lower rear door speaker LH/RH
The lower rear door speaker is located in the lower door trim and is secured by three self tapping screws. The speaker
is protected by a clip on metal grille. The type of lower rear door speaker fitted depends on trim level and market:
lThe base and mid line systems are fitted with full-range door speakers with a power rating of 15 watts and an
impedance of 4 Ω
lThe high line system is fitted with a low-range door speaker with a power rating of 30 watts and an impedance
of 4 Ω.
Low range tail door speakers (high line system only)
The low range tail door speaker are located in a plastic casing in the lower door trim. Each of the two speakers is
secured to the casing with four self tapping screws. The casing is secured to the lower door structure with eight bolts.
The tail door trim surrounds the casing, the front of the casing is covered by a metal grill that is secured with six
screws. The low range tail door speakers have a power rating of 30 watts and has an impedance of 4 Ω.
DESCRIPTION AND OPERAT ION