1999 LAND ROVER DISCOVERY ECU

GENERAL INFORMATION
03-3
Environmental Precautions
General
This section provides general information which can
help to reduce the environmental impacts from the
activities carried out in workshops.
Emissions to air
Many of the activities that are carried out in
workshops emit gases and fumes which contribute to
global warming, depletion of the ozone layer and/or
the formation of photochemical smog at ground
level. By considering how the workshop activities are
carried out, these gases and fumes can be
minimised, thus reducing the impact on the
environment.
Exhaust fumes
Running car engines is an essential part of workshop
activities and exhaust fumes need to be ventilated to
atmosphere. However, the amount of time engines
are running and the position of the vehicle should be
carefully considered at all times, to reduce the
release of poisonous gases and minimise the
inconvenience to people living nearby.
Solvents
Some of the cleaning agents used are solvent based
and will evaporate to atmosphere if used carelessly,
or if cans are left unsealed. All solvent containers
should be firmly closed when not needed and
solvent should be used sparingly. Suitable
alternative materials may be available to replace
some of the commonly used solvents. Similarly,
many paints are solvent based and the spray should
be minimised to reduce solvent emissions.
Refrigerant
It is illegal to release any refrigerants into the
atmosphere. Discharge and replacement of these
materials from air conditioning units should only be
carried out using the correct equipment.
Checklist
Always adhere to the following.
Engines:
ldon't leave engines running unnecessarily;
lminimise testing times and check where the
exhaust fumes are being blown.
Materials:
lkeep lids on containers of solvents;
lonly use the minimum quantity;
lconsider alternative materials;
lminimise over-spray when painting. Gases:
luse the correct equipment for collecting
refrigerants;
ldon't burn rubbish on site.
Discharges to water
Most sites will have two systems for discharging
water: storm drains and foul drains. Storm drains
should only receive clean water, foul drains will take
dirty water.
The foul drain will accept many of the normal waste
waters such as washing water, detergents and
domestic type wastes, but oil, petrol, solvent, acids,
hydraulic oil, antifreeze and other such substances
should never be poured down the drain. If in any
doubt speak to the Water Company first.
Every precaution must be taken to prevent spillage of
oil, fuel, solvents etc. reaching the drains. All
handling of such materials must take place well away
from the drains and preferably in an area with a kerb
or wall around it, to prevent discharge into the drain.
If a spillage occurs it should be soaked up
immediately. Having a spill kit available will make
this easier.
Additional precautions
Check whether the surface water drains are
connected to an oil water separator, this could
reduce the pollution if an incident was to occur. Oil
water separators do need regular maintenance to
ensure effectiveness.
Checklist
Always adhere to the following.
Disposal:
lnever pour anything down a drain without first
checking that it is environmentally safe to do so,
and that it does not contravene any local
regulations or bye-laws;
l have oil traps emptied regularly.
Spillage prevention:
lstore liquids in a walled area;
lmake sure that taps on liquid containers are
secure and cannot be accidentally turned on;
lprotect bulk storage tanks from vandalism by
locking the valves;
ltransfer liquids from one container to another in
an area away from open drains;
lensure lids are replaced securely on containers;
lhave spill kits available near to points of storage
and handling of liquids.

GENERAL INFORMATION
03-13
Self-locking nuts
Self-locking nuts, i.e. nylon insert or deferred thread
nuts can be re-used providing resistance can be felt
when the locking portion of the nut passes over the
thread of the bolt or stud.
Where self-locking nuts have been removed, it is
advisable to replace them with new ones of the same
type.
Flexible Pipes and Hoses
General
When removing and installing flexible hydraulic pipes
and hoses, ensure that the following practices are
observed to ensure component serviceability.
lBefore removing any brake or power steering
hose, clean end fittings and area surrounding
them as thoroughly as possible.
lObtain appropriate plugs or caps before
detaching hose end fittings, so that the ports can
be immediately covered to prevent the ingress
of dirt.
lClean hose externally and blow through with
airline. Examine carefully for cracks, separation
of plies, security of end fittings and external
damage. Reject any faulty hoses.
lWhen refitting a hose, ensure that no
unnecessary bends are introduced, and that
hose is not twisted before or during tightening of
union nuts.
lFit a cap to seal a hydraulic union and a plug to
its socket after removal to prevent ingress of
dirt.
lAbsolute cleanliness must be observed with
hydraulic components at all times.
lAfter any work on hydraulic systems, carefully
inspect for leaks underneath the vehicle while a
second operator applies maximum brake
pressure to the brakes (engine running) and
operates the steering.

GENERAL INFORMATION
03-15
Hose clips
Markings (4) are usually provided on the hose to
indicate the correct clip position. If no markings are
provided, position the clip directly behind the
retaining lip at the end of the stub as shown. Worm
drive clips should be oriented with the crimped side
of the drive housing (5) facing towards the end of the
hose, or the hose may become pinched between the
clip and the stub pipe retaining lip. Worm drive clips
should be tightened to 3 Nm (2 lbf.ft) unless
otherwise stated. Ensure that hose clips do not foul
adjacent components.
Heat protection
Always ensure that heatshields and protective
sheathing are in good condition. Replace if damage
is evident. Particular care must be taken when
routing hoses close to hot engine components, such
as the exhaust manifold and the Exhaust Gas
Recirculation (EGR) pipe. Hoses will relax and
deflect slightly when hot; ensure this movement is
taken into account when routing and securing hoses.
Rolling Road Testing
General
IMPORTANT: Use a four wheel rolling road for
brake testing if possible.
WARNING: Do not attempt to test ABS function
on a rolling road.
Four wheel rolling road
Provided that front and rear rollers are rotating at
identical speeds and that normal workshop safety
standards are applied, there is no speed restriction
during testing except any that may apply to the tyres.
Before testing a vehicle with anti-lock brakes on a
four wheel rolling road, disconnect the ABS
modulator. The ABS function will not work, the ABS
warning light will illuminate. Normal braking will be
available.
Two wheel rolling road
Up to 03MY
ABS will not function on a two wheel rolling road. The
ABS light will illuminate during testing. Normal
braking will be available.
If brake testing on a two wheel rolling road is
necessary, the following precautions should be
taken:
lPropeller shaft to the rear axle is removed.
lNeutral selected in gearbox.
When checking brakes, run engine at idle speed to
maintain servo vacuum.
From 03MY
The differential lock must be engaged for two wheel
rolling road testing. It will also be necessary to
disconnect the propeller shaft from the transfer box
output shaft driving the axle whose wheels are NOT
on the rolling road. Additionally, the ETC system
must be deactivated by either removing the 10 amp
fuse (Number 28, labelled ABS in the main fuse box)
or disconnecting the ABS modulator pump. This
must be done with the ignition OFF ; a fault in the
ABS system may still be recorded.
WARNING; VEHICLES NOT FITTED WITH A
DIFFERENTIAL LOCK MUST NOT BE TESTED
ON A ROLLING ROAD WHERE THE ROLLERS
ARE DRIVEN BY THE VEHICLE.

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
03-20
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