steering LAND ROVER DISCOVERY 2002 Owner's Manual

ENGINE MANAGEMENT SYSTEM - TD5
18-1-36 DESCRIPTION AND OPERATION
Cruise control set/accelerate (SET+) switch
The cruise control SET+ switch is located on the vehicle steering wheel. The switch is a momentary switch and when
pressed by the driver reacts as follows:
lRequests the cruise control to become active and set at the current road speed if not already set.
lIf the cruise control is already set, pressing the switch increases the road speed at 1 mph (1.6 km/h) intervals.
The cruise control SET+ switch will only become active and operate under the following conditions:
lThe vehicle speed must be above 22 mph (35 km/h).
lThe cruise control master switch must be 'on'.
lThe brake pedal must not be pressed.
lThe automatic transmission must be in 'drive'.
lThe clutch pedal must not be pressed.
lThe suspend switch has not been operated.
Input/Output
Input to the cruise control SET+ switch is 12 volts via the main relay. When the switch is pressed the circuit is
completed by the ECM providing an earth path for the relay via pin 11 of connector C0658 of the ECM.
The cruise control SET+ switch can fail as follows:
lOpen circuit.
lShort circuit to voltage supply.
lShort circuit to vehicle earth.
lWiring loom fault In the event of a cruise control SET+ switch failure cruise control does not operate.
Cruise control resume/suspend (RES) switch
The cruise control RES switch is located on the vehicle steering wheel. The switch is a momentary switch and when
pressed by the driver reacts as follows:
lRequests the cruise control to be suspended if it has already been set.
lRequests that cruise control is resumed at the previously set road speed.
The cruise control RES switch will only become active and operate under the following conditions:
lThe vehicle speed must be above 22 mph (35 km/h).
lThe cruise control master switch must be 'on'.
lThe brake pedal must not be pressed.
lThe automatic transmission must be in 'drive'.
lThe clutch pedal must not be pressed.

ENGINE MANAGEMENT SYSTEM - TD5
REPAIRS 18-1-63
Switch - cruise control (set/resume)
$% 19.75.33
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.
3.Release remote control switches multiplug and
leads from steering wheel base.
4.Disconnect remote control switches multiplug
from harness.
5.Remove 2 screws securing remote control
switches to steering wheel base.
6.Release and remove remote control switches
from steering wheel.
Refit
1.Fit remote control switches to steering wheel
and secure with screws.
2.Connect remote control switches multiplug to
harness.
3.Secure leads and multiplug to base of steering
wheel.
4.Fit driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.
Switch - clutch
$% 19.75.34
Remove
1.Disconnect the multiplug from the clutch switch.
2.Position a container below the clutch switch to
collect the fluid.
3.Unscrew and remove the clutch switch.
CAUTION: Always fit plugs to open
connections to prevent contamination.
Refit
1.Fit the clutch switch and tighten to 10 Nm (7
lbf.ft).
2.Connect the multiplug.
3.Bleed the clutch hydraulic system.

+ CLUTCH - Td5, ADJUSTMENTS,
Clutch hydraulic system - bleed.

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-57
Description - cruise control
General
All markets have a common cruise control system. The cruise control system, when activated, regulates vehicle
speed. The system consists of an electrical sub-system and a mechanical sub-system.
The electrical sub-system consists of the following components:
lCruise control master switch (on/off switch).
lSET+ switch.
lRES switch.
lCruise control ECU.
lVacuum pump assembly.
lBrake pedal switch.
lClutch pedal switch (manual gearbox only).
lSLABS ECU (speed signal).
lBCU (brake pedal switch and automatic gearbox gear selector lever position signal).
The mechanical sub-system consists of the following components:
lPneumatic actuator.
lVacuum pump.
The cruise control ECU controls the cruise control system. It is located on the right hand A post.
The system has diagnostic capabilities through TestBook.
WARNING: To avoid the risk of losing control of the vehicle, do not use cruise control on winding, snow
covered or slippery roads, or in traffic conditions where a constant speed cannot be safely maintained. In
these conditions and at any time the system is not being used, ensure the cruise control switch is OFF.
Cruise control master switch
The cruise control master switch switches the system on and off. When the cruise control master switch is on, an
LED within the switch illuminates. If the cruise control master switch is off, cruise control will not operate. The switch
provides a 12 Volt feed to the cruise control ECU.
The cruise control master switch is located on the instrument panel near the steering column.

ENGINE MANAGEMENT SYSTEM - V8
18-2-60 DESCRIPTION AND OPERATION
SET+/RES switches
The cruise control system uses two steering wheel switches labelled SET+ and RES.
The SET+ switch performs the set speed, tap up and accelerator functions. The RES switch performs the resume and
suspend functions.
With the cruise control master switch on and the vehicle in the cruise control operating speed range, one press of the
SET+ switch stores a speed value in the cruise control ECU. If the switch is pressed and held while the vehicle is
under cruise control operation, speed increases until the switch is released. At this point the cruise control ECU stores
the new speed value. If the switch is tapped (held down for less than 0.5 second) the cruise control ECU increases
vehicle speed by 1 mph (1.5 km/h).
If the RES switch is pressed while the systems is inactive (no stored values) the system will not respond. If there is
a stored value in the cruise control ECU memory and the switch is pressed, the cruise control system operates and
holds the vehicle at the stored road speed. If the cruise control system is active and the RES switch is depressed,
the cruise control ECU deactivates cruise operation but maintains the current set speed value.
Input/Output
The input from the SET+ switch to the cruise control ECU is either 12 Volts or an open circuit.
The input from the RES switch to the cruise control ECU is either 12 Volts or an open circuit.
The following diagnostic information is available through TestBook:
lThe state of operator switch SET+.
lThe state of operator switch RES.
ECU operating parameters (connector connected)
Pin No. Condition Volts Ohms
4 Ignition in position II, SET+ switch
releasedMore than 10,000
4 Ignition in position II, SET+ switch
pressed12
2 Ignition in position II, RES switch
releasedMore than 10,000
2 Ignition in position II, RES switch
pressed12

ENGINE MANAGEMENT SYSTEM - V8
REPAIRS 18-2-87
Switch - cruise control (on/off)
$% 19.75.30
Remove
1.Carefully remove switch from instrument cowl.
2.Disconnect multiplug and remove switch.
Refit
1.Position new switch and connect multiplug.
2.Carefully push switch into instrument cowl.
Switch - cruise control (set/resume)
$% 19.75.33
Remove
1.Remove the key from the starter switch.
Disconnect both battery leads, negative lead
first. Wait ten minutes before starting work.
2.Remove driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.
3.Release remote control switches multiplug and
leads from steering wheel base.
4.Disconnect remote control switches multiplug
from harness.
5.Remove 2 screws securing remote control
switches to steering wheel base.
6.Release and remove remote control switches
from steering wheel.
Refit
1.Fit remote control switches to steering wheel
and secure with screws.
2.Connect remote control switches multiplug to
harness.
3.Secure leads and multiplug to base of steering
wheel.
4.Fit driver's airbag module.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - drivers.

FRONT AXLE
DESCRIPTION AND OPERATION 54-1
FRONT AXLE DESCRIPTION AND OPERAT ION
Front axle component layout
1Stake nut
2Hub flange
3Hub bearing
4Steering knuckle
5Drive shaft
6Oil seal
7Bolt
8Bolt
9Washer10Drive flange
11Oil seal
12Differential unit
13Drain plug
14Axle casing
15Breather tube
16Oil level plug
17'O' ring

FRONT AXLE
54-2 DESCRIPTION AND OPERATION
Description
General
The front axle consists of an axle casing with a differential unit attached to the right of the vehicle centre line. A wheel
hub is installed in a steering knuckle at each end of the axle casing and connected to the differential unit by a drive
shaft.
Axle casing
The axle casing is of welded construction, with brackets on the casing exterior for attachment to the front suspension.
Yokes at each end of the casing incorporate upper and lower ball joints for attachment of the steering knuckles.
A differential cover on the front of the axle casing contains an oil level plug for checking and replenishment of the
differential lubricating oil. A magnetic drain plug is installed on the underside of the casing. An oil seal is installed in
each end of the axle casing to prevent leakage past the drive shafts.
The interior of the axle casing is ventilated through a breather tube inserted in a red plastic sleeve in the top of the
casing. The open end of the breather tube is located in the left rear corner of the engine compartment.
Differential unit
The differential unit is of the spiral bevel type, lubricated by splash oil. The unit consists of a differential carrier
attached to a pinion housing. In the pinion housing, the pinion is splined to a drive flange which is secured with a bolt
and washer. An oil seal prevents leakage past the drive flange.
Steering knuckle
The steering knuckles are mounted on upper and lower ball joints in the yokes at the end of the axle casing. A tension
collet, in the lower mounting point of each steering knuckle, accommodates manufacturing tolerances to enable the
correct tightening of both ball joints. Lugs are incorporated on the steering knuckles for attachment of the steering
system drag link and track rod.

FRONT AXLE
DESCRIPTION AND OPERATION 54-3
Wheel hub
Section through wheel hub
1Drive shaft
2Axle casing
3Gaiter
4Upper ball joint
5Constant velocity joint
6Steering knuckle
7Hub bearing
8Hub flange9Wheel stud
10Stake nut
11ABS sensor ring
12Tension collet
13Lower ball joint
14Securing bands
15Shield
16Oil seal
Each wheel hub consists of a hub flange pressed into a hub bearing.
The hub flange is splined to accept the constant velocity joint of the drive shaft, which is secured to the hub flange
with a stake nut. Five studs are installed in the hub flange for the wheel nuts and a threaded hole is provided for the
brake disc securing screw.
The outer race of the hub bearing is bolted to the steering knuckle. The hub bearing is a sealed unit which contains
twin opposed roller bearings, pre-packed with grease during manufacture. A toothed ABS sensor ring is integrated
into the inner race of the hub bearing. An opening in the outer race of the hub bearing accommodates the ABS sensor.

FRONT AXLE
54-6 REPAIRS
9.Remove 4 bolts securing each front wheel hub
to front axle.
10.Release wheel hubs from front axle. Remove
wheel hubs and drive shafts from front axle.
11.Remove oil seal from axle casing.
12.Remove 10 bolts securing differential to axle
casing. Release and remove differential from
axle casing.Refit
1.Clean drive shaft oil seal recess, oil seal
running surface, wheel hub and axle mating
faces.
2.Using a suitable solvent, clean old RTV sealant
from differential and axle mating faces.
3.Apply RTV sealant to differential or axle mating
face.
4.Apply Loctite 243 to threads of differential
securing bolts.
5.Fit differential to axle, fit bolts and tighten to 55
Nm (41 lbf.ft).
6.Position propeller shaft and align reference
marks. Fit bolts and tighten to 47 Nm (35 lbf.ft).
7.Lubricate oil seal lip and running surface with
clean differential oil.
+ CAPACITIES, FLUIDS AND
LUBRICANTS, Lubrication.
8.Using LRT-54-012 and LRT-99-003, fit new
drive shaft oil seal to axle casing.
9.Apply anti-seize compound to wheel hub and
steering knuckle mating faces.
10.Ensure ABS harnesses are located in cut out in
steering knuckles.
11.Fit drive shafts in axle casing and align wheel
hubs with steering knuckles. Fit wheel hub bolts
and tighten to 100 Nm (74 lbf.ft).
12.Connect each ABS sensor multiplug and
secure harness to harness bracket and brake
hose.

FRONT AXLE
REPAIRS 54-9
Seal - oil - front axle casing
$% 54.15.04
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove road wheel.
3.Remove front brake disc.

+ BRAKES, REPAIRS, Brake disc -
front.
4.Disconnect ABS sensor multiplug.5.Release harness from brake hose and hose
bracket.
6.Remove 4 bolts securing wheel hub to steering
knuckle.
7.Release wheel hub from steering knuckle.
8.Remove wheel hub and drive shaft from axle.