warning light LAND ROVER DISCOVERY 2002 User Guide

EMISSION CONTROL - V8
17-2-40 DESCRIPTION AND OPERATION
EVAP system, leak detection diagnostic (vacuum type)
The EVAP system leak detection is performed as follows:
1The ECM checks that the signal from the fuel tank pressure sensor is within the expected range. If the signal is
not within range, the leakage test will be cancelled.
2Next the purge valve is held closed and the canister vent solenoid (CVS) valve is opened to atmosphere. If the
ECM detects a rise in pressure with the valves in this condition, it indicates there is a blockage in the fuel
evaporation line between the CVS valve and the EVAP canister, or that the CVS valve is stuck in the closed
position and thus preventing normalisation of pressure in the fuel evaporation system. In this instance, the
leakage test will be cancelled.
3The CVS valve and the purge valve are both held in the closed position while the ECM checks the fuel tank
pressure sensor. If the fuel tank pressure sensor detects a decline in pressure, it indicates that the purge valve
is not closing properly and vapour is leaking past the valve seat face under the influence of the intake manifold
depression. In this instance, the leakage test will be cancelled.
4If the preliminary checks are satisfactory, a compensation measurement is determined next. Variations in fuel
level occur within the fuel tank, which will influence the pressure signal detected by the fuel tank pressure
sensor. The pressure detected will also be influenced by the rate of change in the fuel tank pressure, caused by
the rate of fuel evaporation which itself is dependent on the ambient temperature conditions. Because of these
variations, it is necessary for the ECM to evaluate the conditions prevailing at a particular instance when testing,
to ensure that the corresponding compensation factor is included in its calculations.
The CVS valve and purge valves are both closed while the ECM checks the signal from the fuel tank pressure
sensor. The rise in fuel pressure detected over a defined period is used to determine the rate of fuel evaporation
and the consequent compensation factor necessary.
5With the CVS valve still closed, the purge valve is opened. The inlet manifold depression present while the purge
valve is open, decreases EVAP system pressure and sets up a small vacuum in the fuel tank. The fuel tank
pressure sensor is monitored by the ECM and if the vacuum gradient does not increase as expected, a large
system leak is assumed by the ECM (e.g. missing or leaking fuel filler cap) and the diagnostic test is terminated.
If the EVAP canister is heavily loaded with hydrocarbons, purging may cause the air:fuel mixture to become
excessively rich, resulting in the upstream oxygen sensors requesting a leaner mix from the ECM to bring the
mixture back to the stoichiometric ideal. This may cause instability in the engine idle speed and consequently
the diagnostic test will have to be abandoned. The ECM checks the status of the upstream oxygen sensors
during the remainder of the diagnostic, to ensure the air:fuel mixture does not adversely affect the engine idle
speed.
6When the fuel tank pressure sensor detects that the required vacuum has been reached (-800 Pa), the purge
valve is closed and the EVAP system is sealed. The ECM then checks the change in the fuel tank pressure
sensor signal (diminishing vacuum) over a period of time, and if it is greater than expected (after taking into
consideration the compensation factor due to fuel evaporation within the tank, determined earlier in the
diagnostic), a leak in the EVAP system is assumed. If the condition remains, the MIL warning light will be turned
on after two drive cycles.
The decrease in vacuum pressure over the defined period must be large enough to correspond to a hole
equivalent to 1 mm (0.04 in.) diameter or greater, to be considered significant enough to warrant the activation
of an emissions system failure warning.
The diagnostic test is repeated at regular intervals during the drive cycle, when the engine is at idle condition. The
diagnostic test will not be able to be performed under the following conditions:
lDuring EVAP canister purging
lDuring fuelling adaption
lIf excess slosh in the fuel tank is detected (excess fuel vapour will be generated, invalidating the result)

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-9
Connector C0658
Pin No. Input/Output Function Signal type Value Interfaces
B1 Input Earth 1 0 volts 0 volts
B2 Input Earth 4 0 volts 0 volts
B3 Input Supply battery voltage 12 volts 12 volts
B4 Output Cooling fan relay Switch 12-0 volts A/C ECU
B5 Output Fuel pump relay Switch 12-0 volts
B6 Output MIL Switch 12-0 volts Instruments
B7 Output Temperature gauge Digital 0-12 volts Instruments
B8 Not used
B9 Input A/C clutch request Switch 12-0 volts A/C ECU
B10 Input Normally closed brake
switchSwitch 12-0 volts
B11 Input Cruise control SET+ switch Switch 12-0 volts
B12 Input TP sensor 1 Analogue 0- 5 volts
B13 Input Vehicle speed Digital 0-12 volts
B14 Input TP sensor supply 5 volts 5 volts
B15 Input Cruise control master switch Switch 12-0 volts
B16 Input Normally open brake switch Switch 0-12 volts
B17 Input Cruise control RES switch Switch 12-0 volts
B18 Input/Output Serial communication link Digital 0-12 volts All ECU's
B19 Output Tachometer engine speed Digital 0-12 volts Instrument
Cluster
B20 Not used
B21 Output Main relay Switch 0-12 volts
B22 Input Supply battery voltage 12 volts 12 volts
B23 Input A/C fan request Switch 12-0 volts
B24 Input Earth 3 0 volts 0 volt
B25 Input Earth 2 0 volts 0 volts
B26 Input TP sensor earth 0 volts 0 volts
B27 Input Supply 2 12 volts 12 volts
B28 Not used
B29 Output A/C relay Switch 12-0 volts
B30 Output Glow plug warning light Switch 12-0 volts Instrument
Cluster
B31 Not used
B32 Output ABS digital 0-5 volts SLABS
B33 Input Ignition Switch 0-12 volts
B34 Input Security code digital 0-5 volts
B35 Input Clutch switch Switch 12-0 volts
B36 Input TP sensor 2 Analogue 5-0 volts

ENGINE MANAGEMENT SYSTEM - V8
18-2-50 DESCRIPTION AND OPERATION
In the case of a VSS failure on vehicles with automatic gearboxes, the ECM applies default values derived from the
EAT ECU. There are no default values for manual gearbox vehicles.
The VSS can fail in the following ways:
lWiring short circuit to vehicle supply.
lWiring short circuit to vehicle earth.
lWiring open circuit.
In the event of a VSS failure, any of the following symptoms may be observed:
lMIL illuminated after 2 driving cycles (NAS only).
lVehicle speed limiting disabled (manual transmission vehicles only).
lSLABS/HDC warning lamp on and audible warning.
Should a malfunction of the component occur the following fault codes may be evident and can be retrieved by
TestBook:
Rough road signal
When the vehicle travels across rough terrain, or on rough roads instability becomes evident in the drive train. The
ECM could interpret these vibrations as a 'false misfire'. To counteract this 'false misfire' the SLABS ECU generates
a rough road signal, sends it to the ECM so that the ECM can suspend misfire detection for as long as the vehicle is
travelling on the 'rough road'.
Function
Input for the rough road signal is measured via pin 34 of connector C0637 of the ECM. The SLABS ECU generates
a PWM signal that varies in accordance with changing road conditions. The rough road PWM signal operates at a
frequency of 2.33 Hz
± 10%. The significance of changes in the PWM signal are shown in the following table:
The rough road signal can fail in the following ways:
lHarness or connector damage
lSLABS failure — wheel speed sensor
A rough road signal failure may be evident from the following:
lHDC / ABS warning light on
P Code J2012 Description Land Rover Description
P0500 Vehicle speed sensor malfunction VSS short or open circuit
P0501 Vehicle speed sensor range/performance VSS implausible
PWM signal Indication
<10% Electrical short circuit to ground
25% ± 5 % Smooth road
50% ± 5 % SLABS error
75% ± 5% Rough road
>90% Electrical short circuit to battery voltage

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-51
Should a malfunction of the rough road signal occur, the following fault codes may be evident and can be retrieved
by TestBook:
Hill Descent Control (HDC) signal
The ECM transmits throttle angle, engine torque, engine identification (Td5 or V8), and transmission type (automatic
or manual) data to the SLABS ECU to support the Hill Descent Control system. The information is transmitted via a
0 – 12V pulse width modulated (PWM) signal at a frequency of 179.27 Hz.
Function
The HDC signal output from the ECM is via pin 29 of connector C0636. The ECM generates a PWM signal that varies
in pulse width in accordance with changing throttle angle or engine torque. The throttle angle data is transmitted on
pulses 1, 3, 5 and 37. The engine torque data is transmitted on pulses 2,4,6 and 38. The engine and transmission
information is transmitted on pulse 39. A synchronising pulse is transmitted after every 39th pulse.
The HDC signal can fail in the following ways:
lHarness or connector damage
A HDC signal failure may be evident from the following:
lHDC / ABS warning light on
lHDC inoperative
lAudible warning
Should a malfunction of the HDC signal occur, the following fault codes may be evident and can be retrieved by
TestBook:
Low fuel level signal
When the fuel level in the fuel tank becomes low enough to illuminate the low fuel level warning lamp in the instrument
cluster, the instrument cluster generates a low fuel level signal. If the low fuel level signal is present during the ECM
misfire detection function the ECM can use it to check for a 'false misfire'.
Conditions
The fuel sender generates the low fuel level signal when the fuel sender resistance is greater than 158
± 8 ohms.
P Code J2012 Description Land Rover Description
P1590 ABS rough road signal circuit malfunction Hardware is OK, but SLABS ECU is sending an error
signal
P1591 ABS rough road signal circuit low Signal from SLABS ECU short circuit to earth
P1592 ABS rough road signal circuit high Signal from SLABS ECU short circuit to vehicle battery
supply
P Code J2012 Description Land Rover Description
P1663 Throttle angle/Torque signal circuit malfunction SLABS HDC link open circuit
P1664 Throttle angle/Torque signal circuit low SLABS HDC link short circuit to ground
P1665 Throttle angle/Torque signal circuit high SLABS HDC link short circuit to battery voltage

FRONT SUSPENSION
REPAIRS 60-37
6.Apply a 3 mm (0.125 in) wide bead of Loctite
640 around drive shaft circumference, as
illustrated.
7.Ensure ABS harness is located in cut out in
steering knuckle.
8.Fit wheel hub to drive shaft and align steering
knuckle. The Loctite will smear along the length
of the splines as the wheel hub is fitted to the
drive shaft.
9.Fit wheel hub bolts and tighten to 100 Nm (74
lbf.ft).
10.Fit new drive shaft nut and lightly tighten.
11.Fit front brake disc.

+ BRAKES, REPAIRS, Brake disc -
front.
12.With assistance, final tighten drive shaft nut to
490 Nm (360 lbf.ft). Stake drive shaft nut. The
drive shaft nut must be tightened before
Loctite has cured.
13.Secure ABS sensor harness to brackets and
secure grommet to inner wing.
14.Fit road wheel and tighten nuts to 140 Nm (103
lbf.ft).
15.Remove stand(s) and lower vehicle.
16.Connect ABS sensor multiplug.
Damper - front
$% 60.30.02
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. RH damper: Release coolant reservoir and
position aside.
4.Loosen through bolt securing damper to turret.
WARNING: Make sure the axle cannot move
when the damper is disconnected. The
damper limits the downward movement of
the axle. If the axle is not restrained,
disconnecting the damper will allow
unrestricted movement which may cause
personal injury or damage to equipment.
M51 0058

BRAKES
70-20 DESCRIPTION AND OPERATION
Operation
Refer to illustration.

+ BRAKES, DESCRIPTION AND OPERATION, Brake system control diagram.
When the ignition is switched on, the SLABS ECU performs a check of the brake related warning lamps as part of the
power up procedure. The warning lamps are illuminated for approximately 3 seconds and then extinguished. If a fault
warning lamp remains illuminated after the lamp check, a fault has been detected and repair action is required.
ABS
The ABS function prevents the road wheels locking during brake application, thus maintaining vehicle stability even
under emergency conditions.
WARNING: ABS is an aid to retaining steering control and stability while braking:
lABS cannot defy the natural laws of physics acting on the vehicle.
lABS will not prevent accidents resulting from excessive cornering speeds, following another vehicle too
closely, aquaplaning, etc.
lThe additional control provided by ABS must never be exploited in a dangerous or reckless manner
which could jeopardise the safety of driver or other road users.
lThe fitting of ABS does not imply that the vehicle will always stop in a shorter distance.
NOTE: During normal braking the feel of the brake pedal on vehicles equipped with ABS will be the same as that on
non ABS vehicles. During anti-lock braking operation the driver will experience feedback in the form of a pulsating
brake pedal and solenoid/pump motor noise from the ABS modulator.
The anti-lock braking function is automatically enabled whenever the ABS modulator is in the normal braking mode.
While the anti-lock braking function is enabled, if the SLABS ECU detects a wheel decelerating faster than the
average and at the calibrated wheel slip limit for ABS operation, it operates the ABS modulator in the ABS braking
mode for the affected wheel.
EBD
The EBD function optimises the distribution of hydraulic pressure between the front and rear axles, under all vehicle
load configurations and road conditions, to maintain vehicle stability during braking. EBD operates in forward and
reverse and is automatically enabled whenever the ABS modulator is in the normal braking mode at vehicle
deceleration rates of 0.3 g and above (i.e. medium to high brake pedal loads). EBD operation is similar to that of ABS,
but is calibrated to intervene at lower wheel slip limits and operates the brakes in axle pairs instead of individually.
During braking, if the SLABS ECU detects the wheels of one axle going slower than those of the other axle, i.e. a
potential wheel slip situation, it signals the ABS modulator to close the inlet solenoid valve for the brakes of the slower
wheels. This prevents any further increase in hydraulic pressure to those brakes, while allowing the hydraulic pressure
to the brakes on the other axle to increase and so maximise the overall braking effort. If the wheel speeds of the axle
being subjected to EBD control return within the calibrated wheel slip limits, the SLABS ECU signals a stepped
opening of the inlet solenoid valves, which allows a progressive increase of hydraulic pressure to the related brakes.
Operation of EBD is detectable from a stiffening of brake pedal movement as the inlet solenoid valves close and a
slight pulsing of the brake pedal as the inlet solenoid valves open. EBD operation ceases immediately the brake pedal
is released.
The wheel slip limit for EBD operation varies with vehicle speed. During normal operation, the inlet solenoid valves
always operate in axle pairs, with only one axle pair closed at any one time. Since the most lightly loaded wheel during
a braking manoeuvre will usually be the first to reach the slip limit, under most vehicle load configurations and road
conditions EBD control occurs on the trailing axle. However, EBD control can occur on the leading axle or switch
between axles during the braking manoeuvre.

BRAKES
REPAIRS 70-37
Switch - brake light
$% 70.35.42
The brake switch is set automatically during fitment.
If the setting is disturbed, the switch can be reset by
depressing the brake pedal and pulling the plunger
out of the switch body, until it contacts the pedal.
Remove
1.Remove 3 fasteners and move drivers side
lower closing panel aside.
2.Disconnect multiplug from brake light switch.
3.Remove brake light switch from pedal bracket.
Refit
1.Engage switch fully into pedal bracket location
and connect multiplug.
2.Position lower closing panel and secure with
fasteners.
Brake pads - front
$% 70.40.02
WARNING: Brake pads must be renewed in axle
sets only, otherwise braking efficiency may be
impaired.
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(s).
3.Remove lower guide pin bolt from caliper and
pivot caliper housing upwards.
4.Remove 2 brake pads from caliper carrier.
Shims are part of the brake pads.
Refit
1.Rotate disc by hand and scrape all scale and
rust from around edge of disc.
2.Scrape rust from pad locating surfaces on
caliper.
3.Clean dust from calipers using brake cleaning
fluid.
WARNING: Do not use compressed air to
clean brake components. Dust from friction
materials can be harmful if inhaled.

RESTRAINT SYSTEMS
REPAIRS 75-25
Airbag module - passenger - deployment
$% 76.74.99
These guidelines are written to aid authorised
personnel to carry out the safe disposal of airbag
modules when removed from the vehicle.
If a vehicle is to be scrapped and contains an
undeployed airbag module, the module must be
manually deployed. This operation should only
be carried out using the following recommended
manual deployment procedure. Before
deployment is started the deployment tool self
test procedure should be carried out.
WARNING: Only use approved deployment
equipment, and only deploy SRS components in
a well ventilated designated area. Ensure SRS
components are not damaged or ruptured before
deployment. Notify the relevant authorities.
Deploy
1.Carry out deployment tool self test.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag deployment tool - self test.
2.Remove airbag module from fascia.

+ RESTRAINT SYSTEMS, REPAIRS,
Airbag module - passenger.3.Position tool SMD 4082/6 in vice, ensuring that
vice jaws grip tool above bottom flange to
prevent possibility of tool being forced upwards
from vice. Tighten vice.
4.Position brackets SMD 4082/7 to tool; lightly
tighten bolts.
5.Position airbag module to tool SMD 4082/6.
Ensure module is correctly secured using all
fixings.
WARNING: When removing, testing or
installing an airbag module, do not lean
directly over it.

SCREENS
76-4-4 REPAIRS
15.Apply a continuous bead of sealant to sealant
face on screen as shown.
16.With assistance, lift screen into place and align
to screen supports and tape. Ensure top
finisher is located into correct position. Lightly
press glass to fully seat sealer.
CAUTION: Do not apply heavy pressure to
the sides of the windscreen. Lightly press
windscreen from centre outwards until
edges are to required gap. Pushing sides
into position can bend windscreen and lead
to cracking in service.
17.Remove protective covers and tape.
18.Test sealer for leaks, apply additional sealer if
necessary. If water is used, allow sealer to dry
before testing. Spray water around glass and
check for leaks. Mark any area that leaks. Dry
glass and sealer then apply additional sealer.
19.Fit interior mirror to slug.
20.If applicable, connect screen heater multiplugs.
21.Fit air intake plenum.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
CAUTION: A curing time of 6 hours is
desirable. During this time leave a window
open to ventilate the vehicle interior. If the
vehicle must be used before the curing time
has elapsed, do not drive at speed or slam
the doors with the windows closed.
CAUTION: Vehicles fitted with a passenger
airbag should not be driven for 24 hours.
Glass - body side - rear
$% 76.81.18
Introduction
The following equipment is required:
lCutting wire and handles.
lKent cutting knife.
lGlazing knife.
lWindscreen repair kit.
lSealant applicator gun.
lSuction cups.
lA felt covered table or stand to support glass.
WARNING: Wear protective gloves when
handling glass, solvents and primers.
WARNING: Wear suitable eye protection when
removing and refitting glass.
Remove
1.If fitted, disconnect coaxial cable from terminal
on glass.
2.Fit protection to exterior body work adjacent to
glass.
3.Cover body panels adjacent to glass.
4.Fit protection to internal trim adjacent to glass.
5.Cover interior of vehicle with protective sheet.

SCREENS
76-4-6 REPAIRS
Glass - alpine light
$% 76.81.52
Introduction
The following equipment is required:
lCutting wire and handles.
lKent cutting knife.
lGlazing knife.
lWindscreen repair kit.
lSealant applicator gun.
lSuction cups.
lA felt covered table or stand to support glass.
WARNING: Wear protective gloves when
handling glass, solvents and primers.
WARNING: Wear suitable eye protection when
removing and refitting glass.
Remove
1.Fit protection to exterior body work adjacent to
glass.
2.Fit cover over adjacent body work.
3.Fit protection to internal trim adjacent to glass.
4.Cover interior of vehicle with protective sheet.
5.From outside of vehicle, use a Kent knife and
carefully cut through sealant to release glass
from body. Any remaining sealant not
accessible with Kent knife can be severed
using cutting wire or knife.
CAUTION: Hold the cutting wire as close to
the glass as possible to prevent damage to
the body and surrounding trim.
6.Remove glass.
CAUTION: Lay glass on felt covered
supports and be careful not to damage the
obscuration band. Do not stand on edge as
this can cause chips which subsequently
develop into cracks.Refit
1.Carefully remove sealant from body to leave a
smooth surface.
2.With assistance, fit glass without sealant to
body and apply masking tape to establish
reference marks as an alignment aid.
3.Remove glass and place aside.
4.Clean body and sealant face on glass with
solvent.
CAUTION: Do not touch cleaned or primed
surfaces with fingers.
5.Apply etch primer to any bare metal on body.
6.Apply glass primer to sealant face on glass and
allow to cure.
7.Apply primer over etch primer on body.
8.Apply activator over old sealant on body.
9.Allow activator to cure.
10.Fit pre-cut nozzle to sealant cartridge, remove
lid, shake out crystals, and fit cartridge to
applicator gun. If necessary modify the nozzle
to achieve required bead section.
11.Apply a continuous bead of sealant to sealant
face on glass as shown.