LAND ROVER DISCOVERY 1999 Repair Manual

GENERAL INFORMATION
03-16
Fuel Handling Precautions
Fuel vapour is highly flammable and in confined
spaces is also explosive and toxic. The vapour is
heavier than air and will always fall to the lowest
level. The vapour can be easily distributed
throughout a workshop by air currents;
consequently, even a small spillage of fuel is
potentially very dangerous.
The following information provides basic precautions
which must be observed if fuel is to be handled
safely. It also outlines other areas of risk which must
not be ignored. This information is issued for basic
guidance only, if in doubt consult your local Fire
Officer.
General
Always have a fire extinguisher containing FOAM,
CO
2, GAS or POWDER close at hand when handling
or draining fuel or when dismantling fuel systems.
Fire extinguishers should also be located in areas
where fuel containers are stored.
Always disconnect the vehicle battery before
carrying out dismantling or draining work on a fuel
system.
Whenever fuel is being handled, drained or stored, or
when fuel systems are being dismantled, all forms of
ignition must be extinguished or removed; any
leadlamps must be flameproof and kept clear of
spillage.
WARNING: No one should be permitted to repair
components associated with fuel without first
having specialist training.
WARNING: Do not remove fuel system
components while the vehicle is over a pit.
Fuel tank draining
Fuel tank draining should be carried out in
accordance with the procedure outlined in the FUEL
DELIVERY section of this manual and observing the
following precautions.
WARNING: Fuel must not be extracted or drained
from any vehicle while it is over a pit. Extraction
or draining of fuel must be carried out in a well
ventilated area.
The capacity of containers must be more than
adequate for the amount of fuel to be extracted or
drained. The container should be clearly marked
with its contents and placed in a safe storage
area which meets the requirements of local
authority regulations.Fuel tank removal
When the fuel line is secured to the fuel tank outlet by
a spring steel clip, the clip must be released before
the fuel line is disconnected or the fuel tank is
removed. This procedure will avoid the possibility of
fumes in the fuel tank being ignited when the clip is
released.
As an added precaution, fuel tanks should have a
'FUEL VAPOUR' warning label attached to them as
soon as they are removed from the vehicle.
Fuel tank repairs - plastic tank
No attempt should be made to repair a plastic fuel
tank. If the structure of the tank is damaged, a new
tank must be fitted.
Body repairs
Plastic fuel pipes are particularly susceptible to heat,
even at relatively low temperature, and can be
melted by heat conducted from some distance away.
When body repairs involve the use of heat, all fuel
pipes which run in the vicinity of the repair area must
be removed, and the tank outlet plugged.
WARNING: If welding is to be carried out in the
vicinity of the fuel tank, the fuel system must be
drained and the tank removed before welding
commences.

GENERAL INFORMATION
03-17
Electrical Precautions
General
The following guidelines are intended to ensure the
safety of the operator while preventing damage to the
electrical and electronic components fitted to the
vehicle. Where necessary, specific precautions are
detailed in the individual procedures of this manual.
Equipment
Prior to commencing any test procedure on the
vehicle ensure that the relevant test equipment is
working correctly and any harness or connectors are
in good condition. It is particularly important to check
the condition of the lead and plugs of mains operated
equipment.
Polarity
Never reverse connect the vehicle battery and
always ensure the correct polarity when connecting
test equipment.
High voltage circuits
Whenever disconnecting live ht circuits always use
insulated pliers and never allow the open end of the
ht lead to contact other components, particularly
ECU's. Exercise caution when measuring the voltage
on the coil terminals while the engine is running, high
voltage spikes can occur on these terminals.Connectors and harnesses
The engine compartment of a vehicle is a particularly
hostile environment for electrical components and
connectors:
lAlways ensure electrically related items are dry
and oil free before disconnecting and
connecting test equipment.
lEnsure disconnected multiplugs and sensors
are protected from being contaminated with oil,
coolant or other solutions. Contamination could
impair performance or result in catastrophic
failure.
lNever force connectors apart using tools to
prise apart or by pulling on the wiring harness.
lAlways ensure locking tabs are disengaged
before disconnection, and match orientation to
enable correct reconnection.
lEnsure that any protection (covers, insulation
etc.) is replaced if disturbed.
Having confirmed a component to be faulty:
lSwitch off the ignition and disconnect the
battery.
lRemove the component and support the
disconnected harness.
lWhen replacing the component keep oily hands
away from electrical connection areas and push
connectors home until any locking tabs fully
engage.
Battery disconnection
Before disconnecting the battery, disable the alarm
system and switch off all electrical equipment. If the
radio is to be serviced, ensure the security code has
been deactivated.
CAUTION: To prevent damage to electrical
components, always disconnect the battery
when working on the vehicle's electrical system.
The ground lead must be disconnected first and
reconnected last.
CAUTION: Always ensure that battery leads are
routed correctly and are not close to any
potential chafing points.
Battery charging
Only recharge the battery with it removed from the
vehicle. Always ensure any battery charging area is
well ventilated and that every precaution is taken to
avoid naked flames and sparks.

GENERAL INFORMATION
03-18
Ignition system safety precautions
The vehicle's ignition system produces high voltage
and the following precautions should be observed
before carrying out any work on the system.
WARNING: Before commencing work on an
ignition system, ensure all high tension
terminals, adapters and diagnostic equipment
are adequately insulated and shielded to prevent
accidental personal contacts and minimise the
risk of shock. Wearers of surgically implanted
pacemaker devices should not be in close
proximity of ignition circuits or diagnostic
equipment.
Disciplines
Switch off the ignition prior to making any connection
or disconnection in the system to prevent electrical
surges caused by disconnecting 'live' connections
damaging electronic components.
Ensure hands and work surfaces are clean and free
of grease, swarf, etc. Grease collects dirt which can
cause electrical tracking (short-circuits) or high-
resistance contacts.
When handling printed circuit boards, treat with care
and hold by the edges only; note that some electronic
components are susceptible to body static.
Connectors should never be subjected to forced
removal or refit, especially inter-board connectors.
Damaged contacts can cause short-circuit and open-
circuit fault conditions.
Prior to commencing test, and periodically during a
test, touch a good vehicle body earth to discharge
static charge. Some electronic components are
vulnerable to the static electricity that may be
generated by the operator.
Grease for electrical connectors
Some under bonnet and under body connectors may
be protected against corrosion by the application of a
special grease during vehicle production. Should
connectors be disturbed in service, repaired or
replaced, additional grease should be applied: Part
No. BAU 5811, available in 150 gm tubs.
NOTE: The use of greases other than BAU 5811
must be avoided as they can migrate into relays,
switches etc. contaminating the contacts and leading
to intermittent operation or failure.
Supplementary Restraint System
Precautions
General
The Supplementary Restraint System (SRS)
provides active protection for vehicle occupants in
the event of a serious collision. The system
components include airbags and pretensioner seat
belts which are automatically deployed when a
severe frontal crash condition is detected.
In order to assure system integrity, it is essential that
the SRS system is regularly checked and maintained
so that it is ready for operation in the event of an
accident.
The SRS system contains components which could
be potentially hazardous to the service engineer if
not serviced and handled correctly. The following
guidelines are intended to alert the service engineer
to potential sources of danger and emphasise the
importance of ensuring integrity of the SRS
components fitted to the vehicle.
Where necessary, additional specific precautions are
detailed in the Restraint Systems section of this
Manual which should be referred to prior to
commencing repair operations.
It should be noted that these precautions are not
restricted to operations performed when servicing
the SRS system. The same care should be exercised
when working on ancillary systems and components
located in the vicinity of SRS components; these
include but are not limited to steering system (driver's
airbag), body and trim components (passenger's
airbag and seat belt pretensioners) and electrical
system components (SRS harnesses etc.).

GENERAL INFORMATION
03-19
WARNING: Do not use rear facing child seats in
the front passenger seat if the vehicle is fitted
with a passenger airbag.
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Replace the airbag every 10 years.
Do not install used SRS parts from another car.
When repairing an SRS system, always use
approved new parts.
Carefully inspect the airbag module before
installing it. Do not install an airbag module that
shows signs of being dropped or improperly
handled, such as dents, cracks or deformation.
Do not try to disassemble or tamper with the
airbag module.
Special bolts are necessary for installing the
airbag module. Do not use other bolts.
Preliminary procedures
The SRS system uses energy reserve capacitors
that keep the system active in the event of electrical
supply failure under crash conditions. It is necessary
to allow the capacitors sufficient time to discharge in
order to avoid the risk of accidental deployment.
Always remove the ignition key from the starter
switch, disconnect the vehicle battery and wait 10
minutes before commencing work on the SRS
system.
Carefully inspect any SRS component before
installation. Do not install any SRS component that
shows signs of damage such as dents, cracks or
deformity.Component handling
The SRS components are sensitive and potentially
hazardous if not handled correctly; always comply
with the following handling precautions:
lNever drop an SRS component. The airbag
Diagnostic Control Unit (DCU) is a particularly
shock sensitive device and must be handled
with extreme care. Airbag modules and seat belt
pretensioner units could deploy if subjected to a
strong shock.
lNever wrap your arms around an airbag
module. If an airbag module has to be carried,
hold it by the cover, with the cover uppermost
and the base away from your body.
lNever transport airbag modules or seat belt
pretensioners in the cabin of a vehicle. Always
use the luggage compartment of the vehicle for
carrying airbag modules and seat belt
pretensioner units.
WARNING: The airbag module contains sodium
azide which is poisonous and extremely
flammable. Contact with water, acid or heavy
metals may produce harmful or explosive
compounds. Do not dismantle, incinerate or
bring into contact with electricity, before the unit
has been deployed.

GENERAL INFORMATION
03-20
Storage
Airbag modules and seat belt pretensioners are
classed as explosive devices. For overnight and
longer term storage, they must be stored in a secure
steel cabinet which has been approved as suitable
for the purpose and has been registered by the local
authority.
For the temporary storage of an airbag module or
seat belt pretensioner during service, place in a
designated storage area. If there is no designated
storage area available, store in the luggage
compartment of the vehicle and inform the workshop
supervisor. Always observe the following
precautions when temporarily storing an airbag
module:
lEnsure the cover is facing upwards and the
luggage compartment is secured.
lAlways keep components cool, dry and free
from contamination.
lDo not allow anything to rest on the airbag
module.
lStore any removed airbag assembly on a
secure flat surface away from electrical
equipment and heat sources exceeding 85°C
(185°F).
WARNING: Store the airbag module or seat belt
pre-tensioner in a designated storage area. If
there is no designated storage area available,
store in the locked luggage compartment/
loadspace of the vehicle and inform the
workshop supervisor.Installation and testing precautions
The integrity of SRS system components are critical
for safety reasons. Ensure the following precautions
are always adhered to:
lNever install used SRS components from
another vehicle or attempt to repair an SRS
component.
lWhen repairing an SRS system, only use
genuine new parts.
lNever apply electrical power to an SRS
component unless instructed to do so as part of
an approved test procedure.
lSpecial Torx bolts are necessary for installing
the airbag assembly. Do not use other bolts.
Ensure bolts are tightened to the specified
torque.
lEnsure that SRS component fixings are
correctly positioned and torqued during service
and repair.
lAlways use new fixings when replacing an SRS
component.
lEnsure the airbag DCU is always installed
correctly. There must not be any gap between
the DCU and the bracket to which it is mounted.
An incorrectly mounted unit could cause the
system to malfunction.
lThe airbag DCU is a non-serviceable
component and no attempt should be made to
repair or modify the unit.
lDo not try to disassemble the airbag assembly.
It has no serviceable parts. Once an airbag has
been deployed, it cannot be repaired or reused.
lIf you suspect an airbag assembly could be
defective, install a new unit and dispose of the
old unit. Manually deploy the old unit before
disposal.
WARNING: Keep clear of the deployment zone
when working on or near an airbag module.
Accidental deployment could cause serious
injury.

GENERAL INFORMATION
03-21
WARNING: Do not use a multimeter or other
general purpose test equipment on SRS system
components or accidental deployment may
occur. Use only Testbook to diagnose system
faults.SRS harnesses and connectors
Always observe the following precautions with
regard to SRS systems:
lNever attempt to modify, splice or repair SRS
wiring. SRS wiring can be identified by a special
yellow outer protective covering (black with
yellow stripe protective coverings are
sometimes used).
lNever install electronic equipment (such as a
mobile telephone, two way radio or in-car
entertainment system) in such a way that it
could generate electrical interference in the
airbag harness. Seek specialist advice when
installing such equipment.
CAUTION: Always ensure the SRS harness is
routed correctly. Avoid trapping or pinching the
SRS harness. Look out for possible chafing
points.
CAUTION: Ensure all SRS harness connectors
are mated correctly and securely fastened. Do
not leave the connectors hanging loose.
CAUTION: Do not allow the airbag module to
hang by the airbag harness.

GENERAL INFORMATION
03-22
Rotary coupler
Always follow the Repair procedure for fitting the
rotary coupler.
Comply with all safety and installation procedures to
ensure the system functions correctly. Observe the
following precautions:
lDo not install a rotary coupler if it is suspected to
be defective.
lDo not attempt to service, modify or repair a
rotary coupler.
lDo not cut, splice or modify the wires attached
to yellow SRS connector and lead.
lAlways ensure the rotary coupler connectors
are mated correctly and securely fastened.
lAlways ensure the battery is disconnected
before working on the rotary coupler.
lAlways ensure the rotary coupler is removed
and installed in its centered position and with the
front road wheels in the straight ahead position.
lIf a new rotary coupler is being installed, ensure
the locking tab holding the coupler's rotational
position is not broken; units with a broken
locking tab should not be used.
Warning labels
Warning symbols are displayed at various positions
in the vehicle (either in a suitable prominent position
such as driver and passenger side glass, or attached
to the component itself) to indicate SRS items which
must be treated with particular care. Exact positions
of SRS warning labels may vary dependent on
legislation and market trends.
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.Side window label
aThe need for caution when working in close
proximity to SRS components.
bRefer to the publication where the procedures,
instructions and advice can be found (usually
the Workshop Manual) for working on the SRS
system.
cDo not use rear facing child seats in the front
passenger seat if the vehicle is fitted with a
passenger airbag.
Rotary coupler label
aRefer to the Workshop Manual for detailed
instructions
bEnsure wheels are in the straight ahead
position before removal and refitting
cPart number/Bar code. The code must be
recorded and quoted for ordering purposes

GENERAL INFORMATION
03-23
Airbag and pretensioner deployment
Deployment procedures and precautions as detailed
in this manual should be strictly adhered to. Only
personnel who have undergone the appropriate
training should undertake deployment of airbag and
pretensioner modules. The following precautions
must be complied with:
lOnly use deployment equipment approved for
the intended purpose.
lBefore beginning deployment procedure,
ensure deployment tool functions properly by
performing the self test procedure detailed in
SRS section of this manual.
lDeployment of airbag/ pretensioner modules
should be performed in a well ventilated area
which has been designated for the purpose.
lEnsure airbag/pretensioner modules are not
damaged or ruptured before attempting to
deploy.
lNotify the relevant authorities of intention to
deploy airbag and pretensioner units.
lWhen deploying airbag pretensioner units,
ensure that all personnel are at least 15 metres
(45 feet) away from the deployment zone.
lEnsure deployment tool is connected correctly,
in compliance with the instructions detailed in
the SRS section of this manual. In particular,
ensure deployment tool is NOT connected to
battery supply before connecting to airbag
module connector.
lWhen deploying seat belt pretensioners, ensure
pretensioner unit is secured correctly to the
seat.
lWhen removing deployed airbag modules and
pretensioner units, wear protective clothing.
Use gloves and seal deployed units in a plastic
bag.
lFollowing deployment of any component of the
SRS system within the vehicle, all SRS
components must be replaced. DO NOT re-use
or salvage any parts of the SRS system.
lDo not lean over airbag module when
connecting deployment equipment.
If a vehicle is to be scrapped, undeployed airbag
modules and pretensioner units must be manually
deployed. In this case airbags can be deployed in the
vehicle; before deployment, ensure the airbag
module is secure within its correct mounting position.
Deployment of the driver's airbag in the vehicle may
damage the steering wheel; if the vehicle is not being
scrapped, deploy the module outside of the vehicle.
WARNING: During deployment parts of the
airbag module become hot enough to burn you.
Wait 30 minutes after deployment before
touching the airbag module.
SRS Component Replacement Policy
The following information details the policy for
replacement of SRS components; either as a result
of a vehicle accident or as a result of vehicle age.
Impacts which do not deploy the airbags or pre-
tensioners
Check for structural damage in the area of the
impact, paying particular attention to bumper
armatures, longitudinals, crash cans and bracketry.
Impacts which deploy the airbags or pre-
tensioners
The replacement and inspection policy is dependent
on the type and severity of of the crash condition.
The following guidelines are the minimum that
should be exercised as a result of the deployment of
specific SRS components.
If the front airbags or seat belt pre-tensioners are
deployed, the following parts must be replaced:
lSRS DCU.
lDriver airbag module
lPassenger airbag module
lFront seat belt buckle pre-tensioners
lRotary coupler
lDriver's seat belt retractor
lFlyleads (where applicable) connecting airbags
and seat belt pre-tensioners to SRS harness
In addition, the following should be inspected for
damage and replaced as necessary:
lFront passenger's seat belt retractor (webbing,
tongue latching, 'D' loop, body anchorage point)
lRear seat belt buckles (webbing, buckle covers,
body anchorage and tongue latching function)
lFascia moulding adjacent to passenger airbag
module
lSteering wheel (if damage is evident)
lFront seat frames and head restraints (if there is
evidence of damage to the seat frame or
cushion pan)
lSteering column (if adjustment is lost or there
are signs of collapse)
lThird row seats, seat belts and head restraints
(where fitted). Check third row seat latching
mechanism operates correctly.
Periodic replacement of SRS components
The performance of the propellants within airbags
and pre-tensioners will deteriorate over a period of
time. As a result, it is essential that the airbags are
replaced after 10 years and seat belt pre-tensioners
are replaced after 15 years in order to maintain
occupant safety.

GENERAL INFORMATION
03-24
Air Conditioning System Precautions
General
The air conditioning system contains fluids and
components which could be potentially hazardous to
the service engineer or the environment if not
serviced and handled correctly. The following
guidelines are intended to alert the service engineer
to potential sources of danger and emphasise the
importance of ensuring the integrity of the Air
Conditioning operating conditions and components
fitted to the vehicle.
Where necessary, additional specific precautions are
detailed in the relevant sections of this Manual which
should be referred to prior to commencing repair
operations.
The refrigerant used in the air conditioning system is
HFC-134a (Hydrofluorocarbon) R134a.
WARNING: Servicing must only be carried out by
personnel familiar with both the vehicle system
and the charging and testing equipment. All
operations must be carried out in a well
ventilated area away from open flame and heat
sources.
WARNING: R134a is a hazardous liquid and when
handled incorrectly can cause serious injury.
Suitable protective clothing, consisting of face
protection, heat proof gloves, rubber boots and
rubber apron or waterproof overalls, must be
worn when carrying out operations on the air
conditioning system.Remedial actions
If an accident involving R134a should occur, conduct
the following remedial actions:
lIf liquid R134a enters the eye, do not rub it.
Gently run large quantities of eye wash over
affected eye to raise the temperature. If an eye
wash is not available, cool, clean water may be
used to flush the eye. After rinsing, cover the
eye with a clean pad and seek immediate
medical attention.
lIf liquid R134a is splashed onto the skin, run
large quantities of water over the affected area
to raise the temperature. Implement the same
action if the skin comes in contact with
discharging cylinders. Wrap the contaminated
body parts in blankets (or similar materials) and
seek immediate medical attention.
lIf the debilitating effects of inhalation of R134a
vapour is suspected, seek fresh air. If the
affected person is unconscious, move them
away from the contaminated area to fresh air
and apply artificial respiration and/or oxygen
and seek immediate medical attention.
WARNING: Due to its low evaporating
temperature, R134a must be handled with care.
R134a splashed on any part of the body will
cause immediate freezing of that area. Also,
refrigerant cylinders and replenishment trolleys
when discharging will freeze skin to them if
contact is made.

GENERAL INFORMATION
03-25
Service precautions
Observe the following precautions when handling
components used in the air conditioning system:
lAir conditioning units must not be lifted by their
hoses, pipes or capillary lines.
lHoses and lines must not be subjected to any
twist or stress; the efficiency of the system will
be impaired by kinks or restrictions. Ensure that
hoses are correctly positioned before tightening
couplings, and ensure that all clips and supports
are utilised.
lFlexible hoses should not be positioned close to
the exhaust manifold (less than 100mm) unless
protected by heat shielding.
lCompleted assemblies must be checked for
refrigeration lines touching metal panels. Any
direct contact of components and panels may
transmit noise and so must be eliminated.
lThe appropriate torque wrench must be used
when tightening refrigerant connections to the
stipulated value. An additional spanner must be
used to hold the union to prevent twisting of the
pipe when tightening connections.
lBefore connecting any hose or pipe, ensure that
refrigerant oil is applied to the seat of the new 'O'
rings, BUT NOT to the threads of the
connection.
lAll protective plugs must remain in place to seal
the component until immediately prior to
connection.
lEnsure components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters it.
lComponents must not remain uncapped for
longer than 15 minutes. In the event of a delay,
the caps must be fitted.
lWhen disconnecting, immediately cap all air
conditioning pipes to prevent ingress of dirt and
moisture into the system.
lThe receiver/drier contains desiccant which
absorbs moisture. It must be positively sealed at
all times. A receiver/drier that has been left
uncapped must not be used, fit a new unit.
lThe receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection
of the system.
lWhenever the refrigerant system is opened, the
receiver/drier must be renewed immediately
before evacuating and recharging the system.
lUse alcohol and a clean lint-free cloth to clean
dirty connections.
lEnsure that all new parts fitted are marked for
use with R134a.
When a major repair has been completed, a leak test
should be conducted; refer to the Air Conditioning
section of this manual for the correct procedure.Refrigerant oil
Refrigerant oil easily absorbs water and must not
be stored for long periods. Do not pour unused
refrigerant oil back into the container. Always
use an approved refrigerant oil.

+ CAPACITIES, FLUIDS, LUBRICANTS
AND SEALANTS, Lubrication.
When replacing components in the A/C system,
drain the refrigerant oil from the component being
replaced into a graduated container. On assembly,
add the quantity of refrigerant oil drained to the new
component.
Compressor
A new compressor is sealed and pressurised with
Nitrogen gas. When fitting a new compressor, slowly
release the sealing cap; gas pressure should be
heard to vent as the seal is broken.
CAUTION: A new compressor should always be
sealed and could be pressurised with nitrogen
gas. To avoid possible oil loss, release the
sealing cap(s) slowly. Do not remove the cap(s)
until immediately prior to connecting the air
conditioning pipes to the compressor.
Rapid refrigerant discharge
If the air conditioning system is involved in accident
damage and the system is punctured, the refrigerant
will discharge rapidly. The rapid discharge of
refrigerant will also result in the loss of most of the oil
from the system. The compressor must be removed
and all the remaining oil in the compressor drained
and refilled as instructed in the air conditioning
section of this manual.