earth LAND ROVER DISCOVERY 2002 Workshop Manual

BRAKES
70-24 DESCRIPTION AND OPERATION
Default strategies
Electrical data
Nominal resistance values for applicable brake control components are as detailed below:
Fault Default strategy
Brake lamps relay ABS: Enabled.
ETC: Enabled.
EBD: Enabled.
HDC: Enabled.
Throttle position signal failure ABS: Enabled.
ETC: Disabled.
EBD: Enabled.
HDC: Immediately disabled if not in active braking mode; faded out then disabled if in active
braking mode.
No reference earth ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.
Return pump or relay fault ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.
Shuttle valve switch failure ABS: Deceleration threshold increased; return pump activated if sum of output valve
actuation on one axle exceeds 140 milliseconds.
ETC: Disabled.
EBD: Inlet valves of rear axle close at vehicle deceleration rates of 0.3 g and above.
HDC: Disabled.
SLABS ECU internal failure ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.
Supply voltage out of limits ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.
Component Resistance, ohms
Brake lamp relay coil117 - 143
Return pump relay coil82.8 - 101.2
ABS sensor950 - 1100
Shuttle valve switches, both open (brakes off) 2977 - 3067
Shuttle valve switches, both closed (brakes on) 1007 - 1037
Shuttle valve switches, one open, one closed 1992 - 2052
Inlet solenoid valve5.9 - 7.3
Outlet solenoid valve3.0 - 3.6

BRAKES
70-26 DESCRIPTION AND OPERATION
Description
General
The handbrake consists of a drum brake, installed on the rear of the transfer box, operated by a cable connected to
a handbrake lever between the front seats.
Handbrake lever
The handbrake lever is mounted on a base plate which attaches to the transmission tunnel. A conventional ratchet
and thumb operated release button are incorporated for locking and unlocking the lever. A warning switch on the base
of the lever operates the brake warning lamp in the instrument pack. While the handbrake is applied the warning
switch connects an earth to the instrument pack which, if the ignition is on, illuminates the brake warning lamp. In
some markets, the instrument pack performs a bulb check of the brake warning lamp each time the ignition is switched
on.
Cable
The handbrake cable consists of inner and outer cables installed between the handbrake lever and the drum brake.
A protective sleeve is installed on the cable to protect the cable from heat from the exhaust system. Handbrake
adjustment is provided by a threaded sleeve installed on the outer cable where it locates in the handbrake lever.
Turning an adjuster wheel, which is keyed to the threaded sleeve and secured by a 'C' clip, alters the effective length
of the outer sleeve and consequently changes the handbrake lever movement needed to apply the drum brake.

RESTRAINT SYSTEMS
75-18 REPAIRS
Pre-tensioner - front seat belt
$% 76.73.30
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove front seat.

+ SEATS, REPAIRS, Seat - front.
3.Release cable tie securing pre-tensioner
harness to seat.
4.Remove Torx screw securing pre-tensioner to
seat.
5.Remove pre-tensioner.
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.
Refit
1.Fit pre-tensioner to seat and tighten Torx bolt to
32 Nm (24 lbf.ft).
2.Secure harness to seat with new cable tie.
3.Fit front seat.

+ SEATS, REPAIRS, Seat - front.
4.Connect battery leads, earth lead last.
Airbag module - drivers
$% 76.74.01
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove 2 Torx bolts securing airbag module to
steering wheel.
3.Release airbag module from steering wheel.
CAUTION: Do not allow the airbag module
to hang by the airbag harness.
4.Disconnect multiplug from airbag module.

RESTRAINT SYSTEMS
REPAIRS 75-19
5.Remove airbag module.
WARNING: Store the airbag module with the
deployment side uppermost. If it is stored
deployment side down, accidental
deployment will propel the airbag module
with enough force to cause serious injury.
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.
Refit
NOTE: If the airbag module is to be replaced,
the bar code of the new module must be
recorded.
1.Position airbag module and connect multiplug.
2.Fit airbag module to steering wheel and tighten
Torx bolts to 9 Nm (7 lbf.ft).
3.Connect battery leads, earth lead last.
Airbag module - passenger
$% 76.74.02
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Release guides supporting glove box.
3.Lower glove box to gain access to airbag
module.

RESTRAINT SYSTEMS
75-20 REPAIRS
4.Disconnect multiplug from airbag module.
5.Remove 4 Torx bolts securing airbag module to
fascia.
6.Remove airbag module from fascia panel.
WARNING: Store the airbag module with the
deployment side uppermost. If it is stored
deployment side down, accidental
deployment will propel the airbag module
with enough force to cause serious injury.
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 luggage compartment
of the vehicle and inform the workshop
supervisor.
Refit
NOTE: If the airbag module is to be replaced,
the bar code of the new module must be
recorded.
1.Fit airbag module to fascia and tighten Torx
bolts to 8 Nm (6 lbf.ft).
2.Connect multiplug to airbag module.
3.Position glove box and engage supporting
guides. Close glove box.
4.Connect battery leads, earth lead last.
DCU
$% 76.74.06
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove centre console.
lOn manual gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
lOn automatic gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
3.Disconnect multiplug from DCU.
4.Remove 3 Torx bolts securing DCU to body and
remove DCU.
CAUTION: The SRS diagnostic control unit
is a non-serviceable component and no
attempt should be made to repair or modify
the unit.

RESTRAINT SYSTEMS
REPAIRS 75-21
Refit
CAUTION: The SRS diagnostic control unit
is a shock sensitive device and must be
handled with extreme care.
1.Position DCU to body and connect multiplug.
2.Fit and tighten DCU Torx bolts to 10 Nm (7
lbf.ft).
3.Fit centre console.
lOn manual gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
lOn automatic gearbox models:

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
4.Connect battery leads, earth lead last.
Rotary coupler
$% 76.74.20
WARNING: It is imperative that before any work
is undertaken on the SRS system the appropriate
information is read thoroughly.
WARNING: Always disconnect both battery leads
before beginning work on the SRS system.
Disconnect the negative battery lead first. Never
reverse connect the battery.
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove steering wheel.

+ STEERING, REPAIRS, Steering
wheel.
3.Remove steering column nacelle.

+ STEERING, REPAIRS, Nacelle -
steering column.

SEATS
76-5-4 DESCRIPTION AND OPERATION
Description - electric seats
General
All markets use the same electric seat system. Electically operated lumbar support is optional. The system consists
of an electrical sub-system and a mechanical sub-system.
The electrical sub-system consists of the following components:
lBCU.
lSeat power relays.
lSeat switch packs.
lSeat fore/ aft motors.
lSeat cushion front up/ down motors.
lSeat cushion rear up/ down motors.
lSeat squab motor.
lLumbar pump.
lLumbar deflate solenoid.
The mechanical sub-system consist of the following components:
lGear wheels.
lRack and pinion assemblies.
Seat power relay
Located beneath the seat, the seat power relay supplies battery voltage to the satellite fuse box. Operation of the
relays is controlled by the BCU.
Voltage to the seat power relays is from fuse 5 in the engine compartment fuse box. The BCU controls the earth for
the relay coils. Operating the seat power relays provides voltage to the satellite fuse box under each seat.
Satellite fuse box
Located beneath the seat, the satellite fuse box provides circuit protection for the wiring to the seat switches and
motors. It also protects the lumbar inflate and deflate circuits.
The seat power relay provides voltage directly to the 40A fuse in the satellite fuse box. Voltage from this fuse feeds
the seat switch pack. The 3A fuses in the satellite fuse box protect the wiring to the lumbar pump and lumbar deflate
solenoid. Voltage to the 3A fuses comes from the seat switch pack.

SEATS
76-5-6 DESCRIPTION AND OPERATION
Two pins within the seat switch pack control the seat fore/ aft motor. Both pins are normally earthed. Operating the
backward switch applies voltage to that pin while the other pin remains earthed. Operating the forward switch reverses
power and earth to the motor allowing the motor to run in the opposite direction.
Seat cushion front up/ down motor
The seat cushion front up/ down motor is a permanent magnet motor coupled to a rack and pinion assembly. Should
the motor seize or stick for 6 seconds or more an internal thermal cut out switch will trip to remove voltage from the
motor. Reset time for the switch is 35 seconds.
Two pins within the seat switch pack control the seat cushion front up/ down motor. Both pins are normally earthed.
Operating the up switch applies voltage to that pin while the other pin remains earthed. Operating the down switch
reverses power and earth to the motor allowing the motor to run in the opposite direction.
Seat cushion rear up/ down motor
The seat cushion rear up/ down motor is a permanent magnet motor coupled to a rack and pinion assembly. Should
the motor seize or stick for 6 seconds or more, an internal thermal cut out switch will trip to remove voltage from the
motor. Reset time for the switch is 35 seconds.
Two pins within the seat switch pack control the seat cushion rear up/ down motor. Both pins are normally earthed.
Operating the up switch applies voltage to that pin while the other pin remains earthed. Operating the down switch
reverses power and earth to the motor allowing the motor to run in the opposite direction.
Seat squab fore/ aft motor
The squab fore/ aft motor is a permanent magnet motor coupled to a rotary rack and pinion assembly. Should the
motor seize or stick for 6 seconds or more, an internal thermal cut out switch will trip to remove voltage from the motor.
Reset time for the switch is 35 seconds.
Two pins within the seat switch pack control the squab fore/ aft motor. Both pins are normally earthed. Operating the
fore switch applies voltage to that pin while the other pin remains earthed. Operating the aft switch reverses power
and earth to the motor allowing the motor to run in the opposite direction.
Lumbar pump
The lumbar pump inflates a bladder in the squab which provides extra support for the seat occupant. With no load on
the seat it takes approximately 10 seconds to completely inflate the bladder. With a load of 25 kg (55 lb) it takes
approximately 15 seconds to inflate the bladder. A pressure cut off switch in the system will operate at 0.12 to 1.93
bar (1.8 to 28 lbf.in
2). If a problem occurs with the lumbar bladder, e.g. a rupture, the whole lumbar system must be
replaced. The components are not serviceable.
Power comes from the seat switch pack through a 3A fuse in the satellite fuse box. The lumbar pump and the lumbar
deflate solenoid share an earth.
Lumbar deflate solenoid
The lumbar deflate solenoid vents the lumbar bladder to atmosphere to allow air to evacuate the bladder. The average
time to evacuate the bladder with a load of 25 kg (55 lb) is 9 seconds.
Power comes from the seat switch pack through a 3A fuse in the satellite fuse box. The lumbar deflate solenoid and
the lumbar pump share an earth.

SEATS
DESCRIPTION AND OPERATION 76-5-7
Operation - electric seats
Seat power relay enable line
The BCU provides the seat power relays with an earth supply to the relay coil that enables the relay operation. When
this seat power relay enable line is active, the seat power relay energises allowing seat operation.
In order for the seat power relay to be active the BCU must detect either of the following condition options:
lIgnition switch in position II.
lIgnition switch in position II or driver's door within 45 seconds of opening.
Seat fore/ aft movement
When the cushion switch is operated and the seat power relay enable line is operating, power and earth are supplied
to the motor in the seat, allowing the seat to move forward or backward depending on switch position. The motor
drives a gear wheel along a gear rack connected to the seat base. Sliding the cushion switch forward causes the motor
to drive the seat forward. Sliding the cushion switch rearward reverses polarity of the voltage at the seat motor, driving
the seat rearward.
Seat cushion front up/ down movement
When the cushion switch is operated and the seat power relay enable line is operating, power and earth are supplied
to the motor in the seat, allowing the front of the seat cushion to move upward or downward depending on switch
position. The motor drives a gear wheel along a gear rack connected to the seat base. Sliding the front of the cushion
switch upward causes the motor to drive the seat upward. Sliding the front of the cushion switch downward reverses
polarity of the voltage at the seat motor driving the seat downward.
Seat cushion rear up/ down movement
When the cushion switch is operated and the seat power relay enable line is operating, power and earth are supplied
to the motor in the seat, allowing the seat to move upwards or downwards depending on switch position. The motor
drives a gear wheel along a gear rack connected to the seat base. Sliding the rear of the cushion switch upward
causes the motor to drive the seat upward. Sliding the rear of the cushion switch downward reverses polarity of the
voltage at the seat motor driving the seat downward.
Squab fore/ aft movement
When the squab switch is operated and the seat power relay enable line is operating, power and earth is supplied to
the motor in the squab, allowing the squab to move forward or backward depending on switch position. The motor
drives a gear wheel along a rotary gear rack connected to the squab. Sliding the squab switch forward causes the
motor to drive the squab forward. Sliding the squab switch rearward reverses polarity of the voltage at the seat motor
driving the squab rearward.
Lumbar inflate/ deflate
Sliding the squab switch upwards when the seat power relay enable line is operating applies voltage to the lumbar
pump. The lumbar pump inflates the lumbar bladder, increasing lumbar support. The lumbar pump and the normally
closed lumbar deflate solenoid hold the air in the bladder. Sliding the squab switch downwards applies voltage to the
deflate solenoid, venting the air in the lumbar bladder to atmosphere, decreasing lumbar support.
Diagnostics
TestBook can only verify that the seat power relay line is enabled. It cannot determine the status of the system or any
of the components.

SEATS
DESCRIPTION AND OPERATION 76-5-11
Description - heated seats
Heated seats
The heated seat system is available on both manual seats and electric seats. The electrical sub-system consists of
the following components:
lSeat heater switches.
lSeat heater elements.
lTemperature control unit (if electric seats are fitted).
lTemperature sensor (if electric seats are fitted).
lThermostat (if manual seats are fitted).
Seat heater switches
The seat heater switches supply an ignition feed to either the temperature control unit (vehicles with electric seats) or
directly to the seat heater elements (vehicles with manual seats). When a seat heater switch is operated, current flows
to the seat heater elements causing them to heat the seat.
The ignition feed comes from fuse 15 in the passenger compartment fuse box.
Seat heater elements
The seat heater elements are located in the seat cushion and squab. The cushion and squab heater elements are
wired in series. Total power consumption at 13.5 volts is approximately 115 Watts.
The cushion heater element has an input feed from the temperature control unit or heater switch and an output to the
squab heater element, which outputs to earth.