2002 LAND ROVER DISCOVERY lock

WIPERS AND WASHERS
84-8 DESCRIPTION AND OPERATION
Description
General
All markets have a common wiper system with headlamp powerwash as an option.
The wipers system comprises two front wipers and one rear wiper which are powered by electric motors. A washer
reservoir is located in the front left hand wheel arch and is fitted with two electric pumps. Each pump supplies washer
fluid to either the front or rear screens. On certain models, a third pump can be fitted to operate a headlamp power
wash function. Operation of the front and rear wipers and washers is controlled by the driver using switches located
on a steering column stalk and push button switches on the fascia.
Control of the wipers and washers is achieved by the following components:
lBCU.
lIDM.
lFront wiper relay.
lFront wash/ wipe switch.
lVariable delay switch.
lFront wiper motor assembly.
lFront washer pump motor.
lRear wiper relay.
lRear wiper switch.
lRear washer switch.
lRear wiper motor.
lRear washer pump motor.
Both the Body Control Unit (BCU) and the Intelligent Driver Module (IDM) control the wiper system. The BCU controls
the time delay function of the wiper system and is located below and behind the passenger glovebox. During engine
cranking the BCU prevents wiper functions. Two relays are located in the passenger compartment fusebox. The
relays control the delay operation of the front and rear wipers. The relays are an integral part of the fusebox and
cannot be renewed separately.
Power for the wiper system is supplied by the IDM, which is integral with the passenger fusebox and cannot be
renewed as a component. A serial communication link allows communication between the IDM and the BCU.
The system has diagnostic capabilities through TestBook.
Front wipers
The two front windscreen wipers are operated by a linkage assembly and an electric motor located under the plenum
grill below the windscreen. The linkage and motor assembly is handed for left and right hand drive vehicles. The motor
is an integral part of the linkage and cannot be replaced separately.
The linkage comprises a pressed steel mounting plate which provides for the attachment of a wheel box at each end.
The mounting plate is secured to the bulkhead with flanged nuts which attach to a stud plate located behind the
bulkhead. A link arm is attached to each wheel box by a short link and secured with circlips. The link arm has an
attachment hole centrally located along its length for the electric motor drive link.
The electric motor is mounted in a recess in the bulkhead below a sealed cover plate. The drive spindle of the motor
protrudes through the cover plate and is fitted with a link. The link is attached to a tapered spline on the motor spindle
and is secured with a lock washer and nut. The opposite end of the link is attached to the central attachment point on
the link arm and secured with a circlip.
Each wheel box has a taper splined shaft which allows for the attachment of the wiper arm which is secured with a
washer and nut. The shaft of each wheel box is passed through a rubber sealed aperture in the plenum. The wiper
arm attachment to the splined shaft has a pivot to which the remainder of the arm is attached. The two parts of the
arm are connected by a spring which controls the pressure of the blade on the screen to a predetermined amount.

WIPERS AND WASHERS
DESCRIPTION AND OPERATION 84-11
The dc motor contains two permanent magnets, three brushes and a park switch. The smaller third brush is utilised
for high-speed operation. Attached to the brush pack are 3 capacitors, which minimise radio interference during wiper
operation. A thermal trip switch attached to the brush plate prevents thermal overload of the motor.
The motor incorporates a worm drive gear unit to transfer the rotary motion into a linear motion of the wiper linkage
assembly.
The front wiper motor receives battery voltage from fuse 19 of the passenger compartment fuse box. For low-speed
operation, including intermittent variable delay operation, the battery voltage to move the wiper motor from the park
position passes through the front wiper relay. When the park switch moves to the closed when operating position,
fuse 19 of the passenger compartment fuse box provides battery voltage directly to the wiper motor.
For high-speed operation, including flick wipe, fuse 19 in the passenger compartment fuse box provides the battery
voltage to move the wiper motor from the park position through the front wash/ wipe switch to the front wiper motor.
To achieve high-speed wiper operation, power is supplied to a third brush that provides a closer distance between the
motor poles. Because the poles of the motor are closer together, the motor operates faster.
Rear wiper
The rear wiper is driven directly from an electric motor located inside the tail door. The motor is mounted inside the
tail door with two bolts, lock washers and washers. The motor mounting brackets have rubber inserts to prevent motor
operating noise being transferred to the door structure. The motor spindle is fitted with a seal and protrudes through
a hole in the tail door outer skin panel. The motor spindle is secured to the tail door with a washer and nut.
The motor output spindle has a taper splined shaft which allows for the attachment of the wiper arm which is secured
with a nut. The wiper arm attachment to the splined shaft has a pivot to which the remainder of the arm is attached.
The two parts of the arm are connected by a spring which controls the pressure of the blade on the window to a
predetermined amount.
The wiper blade is attached to the wiper arms with a clip which allows the blade to pivot. The wiper blade comprises
of a number of levers and yokes to which the rubber wiper is attached. The levers and yokes ensure that the pressure
applied by the arm spring is evenly distributed along the full length of the blade. The rubber wiper is held in the yokes
by a pair of stainless steel strips which also contribute to the even distribution of spring pressure along the blade.
Rear wiper switch
The rear wiper switch is a latching pushbutton switch and is located on the right hand side of the instrument pack.
Activating the rear wiper switch provides an earth signal to the BCU. The BCU signals the IDM to energise the rear
wiper relay, which provides battery voltage to the rear wiper motor.

WIPERS AND WASHERS
REPAIRS 84-23
6.Remove nut securing linkage connecting rod to
wiper motor spindle.
7.Release link from motor spindle.
8.Remove 3 bolts securing motor to mounting
plate and remove motor.
Refit
1.Fit new wiper motor to mounting plate and
secure with bolts.
2.Connect link to motor spindle and tighten nut to
7 Nm (5.2 lbf.ft).
3.Fit motor and linkage to body, connect
multiplug. Tighten all fixings to 2.5 Nm (1.8
lbf.ft).
4.Fit plenum air intake.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
Switch - wiper and washer - windscreen
$% 84.15.34
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
Remove
1.Remove rotary coupler.

+ RESTRAINT SYSTEMS, REPAIRS,
Rotary coupler.
2.Release passive coil from steering column lock
and lower the coil without disconnecting the
harness.
3.Release front wiper delay multiplug from
column switch mounting bracket and
disconnect from harness.
4.Disconnect harness multiplug from wiper
switch.
5.Remove 2 screws securing switch, carefully
raise edge of switch bracket to clear location
peg and remove switch.
Refit
1.Fit new switch to bracket and secure with
screws.
2.Connect harness multiplug to switch.

WIPERS AND WASHERS
84-24 REPAIRS
3.Connect front wiper delay multiplug and fit
multiplug to switch bracket.
4.Fit passive coil to column lock.
5.Fit rotary coupler.

+ RESTRAINT SYSTEMS, REPAIRS,
Rotary coupler.
Jet - washer - headlamp
$% 84.20.08
The procedure to remove the headlamp washer jet
on 03MY vehicles is detailed in the front bumper
finisher job.

+ EXTERIOR FITTINGS, REPAIRS, Trim
finisher - bumper - front - from 03MY.
Remove
1.Remove retaining screw cover from jet
housing.
2.Remove screw securing jet to bumper.
3.Release jet and withdraw sufficiently to gain
access to washer tube. Disconnect tube from
jet and remove jet.
Refit
1.Connect jet to washer tube, ensuring it is
pushed fully home.
2.Locate jet in bumper, retain with screw and fit
screw cover.

CHARGING AND STARTING
REPAIRS 86-1-3
5.Remove alternator from mounting bracket.
6.Remove pulley from alternator.
Refit
1.Fit alternator pulley and tighten nut to 80 Nm
(59 lbf.ft).
2.Position alternator to mounting bracket.
3.Connect alternator cables and tighten B+ nut to
18 Nm (13 lbf.ft), and D+ nut to 5 Nm (3.7 lbf.ft).
4.Locate alternator in mounting bracket.
5.Fit alternator mounting bolts and tighten to 45
Nm (33 lbf.ft).
6.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
Belt - auxiliary drive
$% 86.10.03
Remove
1.Remove viscous fan:
l

+ COOLING SYSTEM - V8,
REPAIRS, Fan - viscous.
l

+ COOLING SYSTEM - Td5,
REPAIRS, Fan - viscous.
2.Turn drive belt tensioner using a 15 mm ring
spanner and release belt from pulleys.
Refit
1.Clean drive belt pulley grooves and ensure
grooves are not damaged.
2.Fit new drive belt around pulleys, ensure belt is
correctly aligned in pulley grooves.
3.With assistance, hold tensioner fully clockwise
and fit drive belt around remaining pulley.
Release tensioner.
4.Fit viscous fan:
l

+ COOLING SYSTEM - Td5,
REPAIRS, Fan - viscous.
l

+ COOLING SYSTEM - V8,
REPAIRS, Fan - viscous.

CHARGING AND STARTING
86-1-4 REPAIRS
Battery
$% 86.15.01
Remove
1.Release fixings and remove battery cover.
2.Disconnect both battery leads, negative lead
first.
3.Remove lock nuts and retaining nuts securing
battery clamp.
4.Remove battery clamp.
5.Remove battery.
Refit
1.Clean battery terminals and coat with
petroleum jelly.
2.Fit battery.
3.Fit battery clamp and tighten retaining nuts and
lock nuts.
4.Fit both battery leads, negative lead last.
5.Fit battery cover and secure fixings.
Battery carrier
$% 86.15.11
Remove
1.Remove battery.

+ CHARGING AND STARTING,
REPAIRS, Battery.
2.Release strap and remove jack.
3.Release coolant hose from clip.
4. Diesel models: Remove screw securing ECM,
release ECM and position aside.
5.Remove 7 bolts securing battery carrier.
6.Remove battery carrier.
NOTE: Do not carry out further dismantling if
component is removed for access only.
7.Remove jack retaining strap, speed nut and
clip.

LIGHTING
REPAIRS 86-2-5
Headlamp - from 03MY
$% 86.40.49
Remove
1.Remove front grille.

+ EXTERIOR FITTINGS, REPAIRS,
Grille - front - from 03MY.
2.Protect bumper.
CAUTION: Always protect paintwork when
removing or refitting any body trims or
bumpers.
3.Open air deflector access panel and remove
Torx screw securing headlamp assembly to the
front panel.
4.Remove 2 screws securing headlamp
assembly to the bonnet locking platform.5.Release headlamp assembly from wing,
disconnect multiplug and remove the headlamp
assembly.
NOTE: Do not carry out further dismantling if
component is removed for access only.
6.Remove scrivet securing headlamp finisher to
headlamp assembly, release and remove the
finisher.
Refit
1.Fit and secure headlamp finisher to the
headlamp assembly.
2.Position headlamp assembly to front panel and
connect the multiplug.
3.Secure headlamp assembly to the front wing.
4.Fit and tighten screws securing headlamp
assembly to the bonnet locking platform.
5.Fit and tighten Torx screw securing headlamp
assembly to the front panel. Close the air
deflector access panel.
6.Remove bumper protection.
7.Fit front grille.

+ EXTERIOR FITTINGS, REPAIRS,
Grille - front - from 03MY.
8.Check headlamp alignment - adjust if
necessary.

+ LIGHTING, ADJUSTMENTS,
Headlamps beam alignment - from 03MY.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-1
BODY CONTROL UNIT DESCRIPTION AND OPERAT ION
Description
General
The Body Control Unit (BCU) is located behind the passenger glovebox and is connected to the main harness by four
connectors on its bottom edge and an additional connector located on the side of the BCU casing. Mounting the BCU
behind the fascia makes it reasonably inaccessible for intruders to disable the anti-theft system.
The BCU uses solid-state microprocessor control to perform logical operations and timing functions for a variety of
the vehicle's electrically operated systems, these include:
lDoor locking.
lAnti-theft alarm and immobilisation system.
lExterior lighting including direction indicators and hazard warning lamps.
lCourtesy lighting.
lWipers and washers.
lElectric windows and sunroof.
lHeated windows.
The BCU also communicates with several other electronically controlled systems such as the EAT ECU and SLABS
ECU and also has a datalink between the Intelligent Driver Module (IDM) and the instrument pack. The datalink is a
low speed bus capable of transmitting and receiving messages at a data rate of 10,400 bits per second. Additional
inputs and outputs to peripheral devices are included which are necessary for determining vehicle status for particular
logical operations e.g. crank, ignition key inserted, fuel flap enable etc.
The BCU receives its power supply from the engine compartment fuse box, and is protected by a 10 A fuse.
The BCU communicates with the IDM to provide the control signals to perform power switching operations in
conjunction with dedicated relays.
IDM
The IDM is integrated into the passenger compartment fuse box, which is mounted behind the fascia below the
steering column. There are no harnesses between the fuse box and the IDM. The IDM performs the power switching
operations for several of the vehicle's electrical systems.
The IDM communicates with the BCU and the instrument pack via a serial interface. If the BCU or the IDM is replaced,
the communications link between the two units has to be re-established. This can be done either by switching on the
ignition and leaving it on for five minutes, or by using TestBook. The vehicle immobilisation will remain active until the
communications link between the BCU and IDM has been re-established.
Transit mode
To prevent excessive battery drain during transit to overseas markets, the vehicle is placed in a transit mode. The
following functions are disabled when the vehicle is in transit mode:
lVolumetric sensors.
lPassive immobilisation.
lImmobilisation of the vehicle by use of door lock.
lIgnition key interlock.
lElectric seat enable time-out with driver's door open.