1999 LAND ROVER DISCOVERY airbag off

CONTENTS
18 CONTENTS
RESTRAINT SYSTEMS ............................................................................ 75-1
DESCRIPTION AND OPERATION
SRS component layout ................................................................................................................... 75-1
SRS block diagram ......................................................................................................................... 75-2
Description - SRS ........................................................................................................................... 75-3
Operation - SRS ............................................................................................................................. 75-9
DESCRIPTION AND OPERATION
Description - seat belts ................................................................................................................... 75-11
REPAIRS
Seat belt - front .............................................................................................................................. 75-13
Seat belt - rear - centre ................................................................................................................. 75-13
Seat belt - rear - side .................................................................................................................... 75-15
Mounting - seat belt - 'B' post ...................................................................................................... 75-16
Seat belts - third row ....................................................................................................................... 75-17
Pre-tensioner - front seat belt ....................................................................................................... 75-18
Pre-tensioner - seat belt - front - deployment - in vehicle ............................................................... 75-19
Pre-tensioner - seat belt - front - deployment - off vehicle .............................................................. 75-20
Airbag module - drivers .................................................................................................................. 75-22
Airbag module - passenger ........................................................................................................... 75-23
DCU ................................................................................................................................................ 75-24
Air bag - steering wheel - deployment - off vehicle ......................................................................... 75-25
Air bag - fascia - passenger - deployment - in vehicle ................................................................... 75-26
Air bag - fascia - passenger - deployment - off vehicle .................................................................. 75-27
Rotary coupler ................................................................................................................................ 75-29
DOORS...................................................................................................... 76-1-1
REPAIRS
Door - front .................................................................................................................................... 76-1-1
Door - rear .................................................................................................................................... 76-1-2
Door - tail ........................................................................................................................................ 76-1-3
Glass - front or rear door .............................................................................................................. 76-1-5
Quarter light ................................................................................................................................... 76-1-6
Regulator and motor - front and rear door glass .......................................................................... 76-1-7
Trim casing - front door .................................................................................................................. 76-1-8
Trim casing - rear door .................................................................................................................. 76-1-9
Trim casing - tail door .................................................................................................................... 76-1-10
Latch and motor - front door .......................................................................................................... 76-1-11
Latch and motor - rear door ........................................................................................................... 76-1-12
Latch and motor - tail door ............................................................................................................ 76-1-13
Handle - exterior - rear door ......................................................................................................... 76-1-13
Handle - exterior - tail door ........................................................................................................... 76-1-14
Handle - exterior - front door .......................................................................................................... 76-1-14

GENERAL INFORMATION
03-5
Checklist
Always adhere to the following.
Electricity and heating:
lkeep doors and windows closed in the winter;
lswitch off machinery or lights when not needed;
luse energy efficient heating systems;
lswitch off computers and photocopiers when
not needed.
Fuel:
ldon't run engines unnecessarily;
lthink about whether journeys are necessary and
drive to conserve fuel.
Water:
ldon't leave taps and hose pipes running;
lmend leaks quickly, don't be wasteful.
Compressed air:
ldon't leave valves open;
lmend leaks quickly;
ldon't leave the compressor running when not
needed.
Use of environmentally damaging materials:
lcheck whether a less toxic material is available.
Handling and storage of materials:
lhave the correct facilities available for handling
liquids to prevent spillage and wastage as listed
above;
lprovide suitable locations for storage to prevent
frost damage or other deterioration.
Waste Management
One of the major ways that pollution can be reduced
is by the careful handling, storage and disposal of all
waste materials that occur on sites. Legislation
makes it illegal to dispose of waste materials other
than to licensed waste carriers and disposal sites.
This means that it is necessary to not only know what
the waste materials are, but also to have the
necessary documentation and licenses.
Handling and storage of waste
Ensure that waste materials are not poured down the
drain or onto soils. They should be stored in such a
way as to prevent the escape of the material to land,
water or air.
They must also be segregated into different types of
waste e.g. oil, metals, batteries, used vehicle
components. This will prevent any reaction between
different materials and assist in disposal.Disposal of waste
Disposal of waste materials must only be to waste
carriers who are licensed to carry those particular
waste materials and all the necessary
documentation must be completed. The waste
carrier is responsible for ensuring that the waste is
taken to the correct disposal sites.
Dispose of waste in accordance with the following
guidelines.
lFuel, hydraulic fluid, anti-freeze and oil: keep
separate and dispose of to specialist contractor.
lRefrigerant: collect in specialist equipment and
reuse.
lDetergents: safe to pour down the foul drain if
diluted.
lPaint, thinners: keep separate and dispose of
to specialist contractor.
lComponents: send back to supplier for
refurbishment, or disassemble and reuse any
suitable parts. Dispose of the remainder in
ordinary waste.
lSmall parts: reuse any suitable parts, dispose
of the remainder in ordinary waste.
lMetals: can be sold if kept separate from
general waste.
lTyres: keep separate and dispose of to
specialist contractor.
lPackaging: compact as much as possible and
dispose of in ordinary waste.
lAsbestos-containing: keep separate and
dispose of to specialist contractor.
lOily and fuel wastes (e.g. rags, used spill kit
material): keep separate and dispose of to
specialist contractor.
lAir filters: keep separate and dispose of to
specialist contractor.
lRubber/plastics: dispose of in ordinary waste.
lHoses: dispose of in ordinary waste.
lBatteries: keep separate and dispose of to
specialist contractor.
lAirbags - explosives: keep separate and
dispose of to specialist contractor.
lElectrical components: send back to supplier
for refurbishment, or disassemble and reuse
any suitable parts. Dispose of the remainder in
ordinary waste.
lElectronic components: send back to supplier
for refurbishment, or disassemble and reuse
any suitable parts. Dispose of the remainder in
ordinary waste.
lCatalysts: can be sold if kept separate from
general waste
lUsed spill-absorbing material: keep separate
and dispose of to specialist contractor.
lOffice waste: recycle paper and toner and ink
cartridges, dispose of the remainder in ordinary
waste.

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.).

STEERING
57-6 DESCRIPTION AND OPERATION
Tilt adjustment
The column tilt adjuster lever mechanism is located on the LH side of the steering column and allows the upper column
tube, nacelle and steering wheel assemblies to be tilted up or down a maximum of 7.5° or 47 mm (NAS vehicles have
a smaller range of movement than the ROW vehicles).
The pawl of the mechanism is attached to the lower column and is allowed to pivot, a toothed quadrant is fixed to the
upper column tube.
When the lever on the LH side of the steering column is raised the mechanism releases the pawl from the toothed
quadrant, this allows the column to be moved. When the lever is released two return springs pull the pawl into
engagement with the toothed quadrant.
Steering column lock (All except NAS)
The steering column lock houses the ignition switch, ignition illumination light ring, key lock barrel and the alarm
passive coil. The steering lock is attached to the upper column with two shear bolts. The bolts are tightened to a
torque which shears off the heads of the bolts preventing easy removal of the steering lock.
The steering lock operates by a bolt, which emerges when the ignition key is turned to position 'O' and the ignition key
removed. The bolt engages in a lock collar located on the upper shaft in the upper column tube. The lock collar is
attached to the upper shaft by a 'wave form' interference ring. If a high torque is applied via the steering wheel with
the lock engaged, the lock collar will slip on the upper shaft. This prevents damage to the steering lock, yet still
prevents the vehicle from being driven.
Steering column lock (NAS only)
The steering column lock houses the ignition switch, ignition illumination light ring, key lock barrel and the alarm
passive coil. The steering lock is attached to the upper column with two shear bolts. The bolts are tightened to a
torque which shears off the heads of the bolts preventing easy removal of the steering lock.
The steering column lock operates by a bolt, which emerges when the ignition key is turned to position 'O' and the
ignition key removed. The bolt engages in a groove machined into the upper shaft in the column tube.
Steering wheel
The steering wheel comprises a cast centre and wire frame onto which the soft polyurethane foam is moulded. The
steering wheel is located on the upper column shaft by a spline and is secured with a nut. A remote radio control switch
(if fitted) is located on the LH side of the steering wheel, a cruise control switch may be located on the RH side. Horn
switches are located on each side of the centre of the steering wheel and protrude through the airbag module cover.
Both switches are connected by wires to the rotary coupler connector.
Intermediate shaft
One end of the intermediate shaft is attached to the steering column lower shaft by a splined universal joint and a bolt,
the universal joint is part of a rubber coupling assembly. The rubber coupling assembly is covered by a heat shield
and connects to the lower section of the intermediate shaft via a decouple joint. The rubber coupling reduces the
shocks felt by the driver through the steering wheel. A second universal joint on the other end of the intermediate shaft
is held in by a bolt. The universal joint is splined and engages with the splined rotor (input) shaft of the steering box.
The decouple joint consists of a metal plate that has open ended slots, the plate is bolted through the slots into the
other half of the decouple joint. The top half of the decouple joint has a slot that accepts the lower section of the
intermediate shaft. The slotted metal plate clamps the lower section of the intermediate shaft to the top section. An
indicator clip is installed between the slotted metal plate and the top half of the decouple joint.
If the intermediate shaft is compressed in an accident, the slotted metal plate in the decouple joint will disengage if
sufficient force is applied to the front end of the shaft. If the forces involved do not disengage the shaft, the red
indicator clip located in the decouple joint will break off if the shaft moves. The intermediate shaft cannot be repaired
and must be replaced as an assembly if accident damage occurs.