1999 LAND ROVER DISCOVERY oil level

STEERING
ADJUSTMENTS 57-21
13.Remove bolt from steering box pipe retaining
clip. Leaving the PAS reservoir oil pipe in place,
release pipe retaining clip and PAS cooler pipe
from steering box, discard the seal.
14.Fit tool LRT-57-041 to steering box housing.
15.Fit seal to PAS oil cooler pipe.
16.Fit PAS cooler pipe to LRT-57-041 align the
retaining clip to pipes and tighten bolt to 24 Nm
(18 lbf.ft).
17.Connect test hoses LRT-57-002 to LRT-57-
041 and tighten unions. Ensure all pipes and
fittings are clear of engine rotating parts.18.Hang pressure gauge in a safe position under
bonnet.
19. LHD only: Fit turbocharger intercooler feed
pipe and vacuum connection and fit PAS
reservoir to mounting bracket. Fit air intake
hose to turbocharger and air cleaner and
connect multiplug to MAF sensor. The above
parts must be refitted in order to run the
engine.
20.Fill PAS reservoir, connect battery earth lead.
Start engine and allow air to bleed from PAS
system, by turning steering from lock to lock.
Stop engine and check PAS fluid level.
21.Ensure steering system is free from leaks and
maintain maximum fluid level during test.
22.Open the test valve on LRT-57-001 and start
the engine.
23.With the engine at idle and normal running
temperature, slowly turn the steering wheel and
hold on lock.
24.Note reading on pressure gauge.
25.Repeat pressure check on opposite lock, again
noting the reading on the pressure gauge.
26.The test pressure should be between 21 and 62
bar, (300 to 900 lbf/in
2. Pressure will rise to 62
bar (900 lbf/in2) when held on full lock.
27.With the engine at idle, centralise the steering
wheel. Pressure should read 7 bar (100 lbf/in
2)
or below.
28.Pressure outside the above tolerance indicates
a fault.
29.To determine if fault is in steering pump or
steering rack, close the valve on LRT-57-001
for a maximum of five seconds. Pump damage
may occur if test valve is closed for longer
periods.
30.If the gauge does not register between 75 and
103 bar, (1500 lbf/in
2) (maximum pump
pressure), the pump is faulty.
31.If maximum pump pressure is obtained,
suspect the steering box.
32.On completion, stop engine, disconnect battery
earth lead and syphon fluid from PAS reservoir.
33. LHD only: Disconnect multiplug from MAF
sensor, remove air intake hose clips and move
hose aside.
34. LHD only: Release PAS reservoir from
mounting, for access to turbocharger
intercooler pipe.Remove vacuum hose from
turbocharger intercooler pipe.Release clips and
disconnect intercooler pipe from turbocharger.
35.Remove test equipment from tool LRT-57-041.
36.Remove bolt and clip from steering box.
37.Release PAS cooler pipe from tool LRT-57-041
and discard seal. leaving PAS reservoir oil pipe
in place, release tool LRT-57-041 from
steering box and discard seal.

STEERING
ADJUSTMENTS 57-25
7.Syphon PAS fluid from reservoir.
8.Position container to collect PAS fluid spillage.
9.Clean steering box pipe pipe housing.
10.Remove bolt securing pipe clip to steering box.
Leaving the feed pipe from PAS reservoir in
place, release clip and PAS cooler pipe from
steering box. Discard lower 'O' ring.
11.Fit LRT-57-041 adaptor to steering box.
12.Fit PAS cooler pipe to LRT-57-041, align
retaining clip and tighten Allen bolt to 25 Nm (18
lbf.ft).
13.Hang pressure gauge in a safe position under
bonnet.
14.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
15.Connect battery earth lead.
16.Start engine and allow air to bleed from PAS
system by turning steering from lock to lock.
Stop engine and check PAS fluid level.
17.Ensure steering system and test equipment are
free from leaks.
18.Open test valve on LRT-57-001 and start
engine.
19.With the engine at idle, slowly turn the steering
wheel and hold on full lock.
20.Note the pressure reading on LRT-57-005.21.Repeat the pressure check for the opposite full
lock.
22.Test pressure should be between 21 and 62
bar, (300 to 900) psi. Dependant on road
surface.
23.With the engine at idle, centralise the steering
wheel. Pressure should read 7 bar (100 psi) or
below.
24.Pressure outside the above tolerance indicates
a fault.
25.To determine if fault is in steering pump or
steering box, close the valve on LRT-57-001 for
a maximum of 5 seconds. Pump damage may
occur if test valve is closed for longer periods.
26.If gauge does not register between 75 and 103
bar, (1500 psi), (maximum pump pressure), the
pump is faulty.
27.If maximum pump pressure is correct suspect
the steering box.
28.On completion stop engine, disconnect battery
earth lead and syphon fluid from PAS reservoir.
29.Remove test equipment from LRT-57-002.
30.Remove bolt and clip from steering box.
31.Release PAS cooler pipe from LRT-57-041 and
discard 'O' ring. Leaving PAS reservoir oil feed
pipe in place, release LRT-57-041 from
steering box and discard 'O' ring.
32.Fit new 'O' rings to PAS cooler pipe.
33.Fit PAS cooler pipe to steering box, align
retaining clip, fit bolt and tighten to 25 Nm (18
lbf.ft).
34.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
35.Clean chassis member.
36.Fit splash shield and secure with screws.
37.Connect battery earth lead.
38.Start engine.
39.Start engine and allow air to bleed from PAS
system, by turning steering from lock to lock.
40.Visually check PAS system for leaks.
41.Check power steering fluid, if aerated, wait until
fluid is free from bubbles then top-up reservoir
to 'UPPER' level mark.
42.Visually check PAS system for leaks.
43.Dismantle test equipment.

FRONT SUSPENSION
60-18 DESCRIPTION AND OPERATION
ACE Electronic control unit (ECU)
1Body Control Unit (Ref. only)
2Bracket3ACE Electronic control unit
4Attachment nuts 3 off
The ACE ECU is mounted on a bracket behind the passenger glove box and is identified from the other ECU's by its
single electrical harness connector. The single 36 pin connector is located on the lower face of the ECU and mates
with a connector from the main harness. The connector supplies power, ground, signal and sensor information to/from
the ECU for control of the ACE system.
The ACE ECU receives a battery power supply from fuse 15 in the engine compartment fusebox via the ACE relay,
also located in the engine compartment fusebox. The ECU provides an earth path for the relay coil, energising the
coil and supplying power to the ECU.
An ignition on signal is supplied from the ignition switch via fuse 29 in the passenger compartment fusebox. The
ignition on signal provides an input to the ECU which tells the ECU that ignition has been selected on and initiates a
250 ms start time. The start time is used to prevent functions operating when software routines are being initialised.
The ignition on signal, when removed, tells the ECU that the ignition is off. The ECU will remain powered for thirty
seconds after the ignition is turned off. The thirty second period allows the ECU to store values and fault flags in the
memory. These values are read by the ECU when the next ignition on signal is received.
An engine speed signal is transmitted to the ECU from the Engine Control Module (ECM) as a pulsed digital signal.
The engine speed signal is used by the ACE ECU to detect that the engine is running and hydraulic pressure for ACE
system operation is available.
A road speed signal is transmitted to the ACE ECU as a pulsed digital signal from the Self-levelling/Anti-lock Braking
System (SLABS) ECU. The road speed signal is used by the ACE ECU for on and off-road roll compensation.
When reverse gear is selected, an input is received from the reverse lamp switch. When the ACE ECU detects that
reverse gear has been selected, the ACE system reverts to a 'locked bars' condition until reverse gear is disengaged.
The diagnostic connection allows diagnostic interrogation of the ACE ECU. The diagnostic socket allows diagnostic
equipment to be connected to interrogate the ACE ECU for fault codes.

REAR SUSPENSION
64-6 DESCRIPTION AND OPERATION
Description
General
The rear suspension comprises two dampers, two radius arms, a Watts linkage and an anti-roll bar assembly. On
vehicles without Self Levelling Suspension (SLS) coil springs are used. On vehicles with SLS air springs are used.
The anti-roll bar is an essential part of the rear suspension. On vehicles without ACE, a conventional 'passive' anti-
roll bar is fitted. On vehicles fitted with the ACE system, a thicker diameter anti-roll bar, known as a torsion bar, is used
with an actuator at one end.

+ FRONT SUSPENSION, DESCRIPTION AND OPERATION, Description - ACE.
The hydraulic dampers and springs provide springing for each rear wheel. The long travel dampers, springs and
radius arms provide maximum axle articulation and wheel travel for off-road driving. The rear axle is controlled
longitudinally by two forged steel radius arms and transversely by a Watts linkage.
Radius arms
Each radius arm is manufactured from forged steel. Two bushes are pressed into the rear of the radius arm. The rear
of the radius arm is located between a fabricated bracket on the axle and secured through the bushes with two bolts
and nuts. A bush is pressed into the forward end of the radius arm which is located in a fabricated bracket on each
chassis longitudinal and secured through the bush with a bolt and nut. Each radius arm is similar in its construction
to the front radius arms. The rear radius arms are shorter than the front and have a lug for attachment of the SLS
height sensor (when fitted).
The radius arms prevent longitudinal movement of the rear axle and because of their length allow maximum axle
articulation. The stiffness of the bushes in each radius arm also contributes to the vehicle roll stiffness.
Each radius arm has a notch on its lower edge which provides location for the vehicle jack.
Dampers
Two conventional telescopic dampers are used to control body/axle movement. The upper damper mounting is fitted
with a bush which locates in a bracket on the chassis longitudinal. The damper is secured with a bolt which screws
into a captive nut on the bracket. The lower damper mounting is also fitted with a bush and locates in a fabricated
bracket attached to the rear axle. The lower mounting is secured with a bolt which screws into a captive nut on the
bracket. The upper and lower bushes are replaceable items.
Air springs (vehicles with SLS)
On vehicles with SLS fitted, air springs are fitted between the rear axle and the chassis. Each spring is located at its
base on a fabricated platform on the rear axle. The top of the spring locates in a fabricated bracket attached to the
outside of each chassis longitudinal.
The plastic base of the air spring has two lugs which locate in a slotted hole in the rear axle platform. The spring is
secured by rotating the spring through 90°, locating the lug in the platform. The plastic top of the air spring has two
grooved pins which locate in holes in the bracket on the chassis. Two spring clips locate on the grooved pins and
retain the top of the spring in position.
Each air spring comprises a top plate assembly, an air bag and a base piston. The air bag is attached to the top plate
and the piston with a crimped ring. The air bag is made from a flexible rubber material which allows the bag to expand
with air pressure and deform under load. The top plate assembly comprises the plastic top plate with two bonded
grooved pins on its top face. In the centre of the top face is a female connector which allows for the attachment of the
air hose from the SLS compressor. The piston is made from plastic and is shaped to allow the air bag to roll over its
outer diameter. The base of the piston is recessed with a boss moulded in the centre. The boss has two lugs which
provide attachment to the axle platform.
Coil springs (vehicles without SLS)
On vehicles without SLS fitted, coil springs are fitted between the rear axle and the chassis in place of the SLS air
springs. Each spring is located at its base by the lower spring seat which is secured to a fabricated platform on the
rear axle with two bolts. The top of each spring is located in the upper spring seat. The upper spring seat comprises
a pressed metal plate with an outer coating of natural rubber bonded to the plate. The upper spring seat is retained
in position by the compression of the spring.

AIR CONDITIONING
REFRIGERANT RECOVERY, RECYCLING AND RECHARGING 82-27
REFRIGERANT RECOVERY, RECYCLING AND RECHARGING
Refrigerant recovery, recycling and
recharging
$% 82.30.02
Recovery
1.Remove dust caps from high and low pressure
connectors.
2.Connect high and low pressure hoses to
appropriate connections.
3.Open valves on connectors.
4.Turn valves on refrigerant station to correct
positions.
Operate the refrigerant station in accordance
with the manufacturers instructions.
5.Turn Process switch to correct position.
6.Turn Main switch to 'ON'.
7.Allow station to recover refrigerant from
system.
WARNING: Refrigerant must always be
recycled before re-use to ensure that the
purity of the refrigerant is high enough for
safe use in the air conditioning system.
Recycling should always be carried out with
equipment which is design certified by
Underwriter Laboratory Inc. for compliance
with SAE J1991. Other equipment may not
recycle refrigerant to the required level of
purity.
A R134a Refrigerant Recovery Recycling
Recharging Station must not be used with
any other type of refrigerant.
Refrigerant R134a from domestic and
commercial sources must not be used in
motor vehicle air conditioning systems.
8.Close valves on refrigerant station.
9.Turn Main switch to 'OFF'.
10.Close valves on connectors.
11.Disconnect connectors high and low pressure
hoses from connectors.
12.Fit dust caps to connectors. 13.Open tap at rear of station to drain refrigerant
oil.
14.Measure and record quantity of refrigerant oil
recovered from system.
15.Close tap at rear of station.
Evacuation
WARNING: Servicing must only be carried
out by personnel familiar with both the
vehicle system and the charging and testing
equipment. All operations must be carried
out in a well ventilated area away from open
flame and heat sources.
1.Remove dust caps from high and low pressure
connectors.
2.Connect high and low pressure hoses to
appropriate connections.
3.Open valves on connectors.
4.Turn valves on refrigerant station to correct
positions.
5.Turn Process switch to correct position.
6.Turn Main switch to 'ON'.
7.Allow station to evacuate system.

BODY CONTROL UNIT
DESCRIPTION AND OPERATION 86-3-27
If a direction indicator bulb failure or a trailer presence is detected, the following outputs can be generated depending
on the BCU logic states:
lTrailer detected.
lBulb failure detected.
lDirection indicator short circuit.
lDirection indicator relay stuck.
The BCU can be configured whether or not to provide bulb failure warnings.
When the direction indicators are operating, instrument pack direction indicators flash in sequence with the exterior
direction indicators. If a failure of an indicator bulb occurs, the corresponding instrument pack indication lamp will flash
quickly to warn of the problem.
The IDM monitors the current drawn through the circuit to detect for the occurrence of a lamp failure. If an indicator
lamp fails, the IDM detects the drop in current drawn through the resistor and operates the indicator relay at a faster
speed. The fast flash is demonstrated on the instrument pack direction indicator warning lamps to bring attention to
the driver that a direction indicator bulb failure has occurred. The current sense for the related indicator lamps (RH or
LH) are checked when a direction indicator request has been made that lasts for at least 160 ms. The current level
sensed is relative to the number of working bulbs and determines the request generated by the BCU.
The output is signalled to the instrument pack using the serial communications link. If the hazard warning lamps are
operating, both sets of direction indicators are checked using the current sensing functions to check the number of
bulbs on each side of the vehicle.
If the BCU detects that a direction indicator request has not been made, but one or other of the current sense inputs
indicate that current is flowing, a 'Relay stuck' output is generated.
Hazard lamps
The BCU controls the operation of the hazard warning lamps via the IDM and dedicated relays. The hazard warning
lamps are activated under the following conditions:
lThe vehicle is locked and the security system is set (the hazard warning lamps flash three times if the
superlocking feature is used, once if not).
lThe vehicle is unlocked (the hazard warning lamps flash once for a duration of two seconds).
lThe anti-theft alarm system is triggered (the hazard warning lamps flash in phase with and for the duration of the
audible warning).
lThe hazard warning switch is pressed (the hazard warning lamps flash until the hazard warning switch is pressed
for a second time).
lThe inertia switch is triggered (the hazard warning lamps flash until the inertia switch has been reset).
The hazard warning lamp operation may differ dependent on market and customer configuration options.
The hazard warning lamps are operated from a latching pushbutton switch located on the fascia. When the switch is
pressed, both left and right indicator lamps in the instrument pack flash to show that the hazard warning lamps are
operating and all hazard warning lamps flash simultaneously. If a trailer is fitted, the ICM detects this and a trailer
symbol in the instrument pack also flashes to show correct operation of the trailer direction indicators and hazard
warning lamps.
The BCU supplies a reference voltage to the hazard warning switch. When the hazard warning switch is operated an
earth path is completed which signals the BCU that a request for hazard lamp operation has been made. The BCU
then sends a signal to the IDM via the serial data bus to communicate the request. The IDM supplies an earth path
for both direction indicator relay coils simultaneously so that the hazard warning lamps are turned on concurrently.
The IDM controls the timing of the flash operations by continually removing and restoring the earth path to both
direction indicator relay coils simultaneously.
Number of working bulbs Request generated
3 Trailer detected
2 None (bulbs okay)
1 Bulb failure detected
0 Direction indicator short circuit detected

HARNESSES
REPAIRS 86-7-27
94.Disconnect 3 multiplugs from LH rear door
harness.
95.Withdraw harness to interior.
96.Manoeuvre harness over steering column
support bracket.
97.With assistance remove main harness.
Refit
1.With assistance position main harness to body
and manoeuvre over steering column support
bracket.
2.Lay harness in position and secure to floor
clips and retainers.
3.Connect LH and RH rear door multiplugs.
4.Connect CD player multiplug.
5.Position centre console earth headers and
secure with nuts.
6.Fit rear carpet.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Carpet - rear.
7.Connect DCU multiplug.
8.Connect Lucar to handbrake switch.
9.Fit and tighten nuts securing harness to
transmission tunnel.
10.Secure harness to pedal box.
11.Position footwell earth header and secure with
nut.
12.Feed RH side of harness into engine bay.
13.Position carpet.
14.Connect wiper motor multiplug, position
mechanism and secure with nuts and bolts.
15.Connect ECM multiplug.
16.Position RH lower 'A' post earth header and
secure with nut, connect cruise control
multiplug.
17.Connect RH front door and RH side body
harness multiplugs. 18.Secure multiplugs to steering column support
bracket and connect brake and clutch pedal
multiplugs.
19.Connect multiplugs to column switch and
passive coil.
20.Position passenger compartment fusebox,
connect multiplugs, fit fusebox to fascia and
secure with nut.
21.Connect ignition switch multiplug to fuse box.
22.With assistance feed LH side of harness into
engine bay.
23.Connect multiplugs to front door harness and
body harness.
24.Position earth headers to LH lower 'A' post and
secure with nuts.
25.Connect multiplugs to ECU pack.
26.Position harness in engine bay.
27.Connect and secure heated front screen
multiplugs.
28.Fit plenum molding.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
29.Connect multiplugs to ABS sensor and fuel
cut-off switch.
30.Using draw string feed harness through inner
wing, remove draw string, connect repeater
lamp multiplug and fit lamp.
31.Connect multiplugs to ABS modulator.
32.Feed harness through to front panel.
33.Position body earth leads and secure with
bolts.
34.Connect washer reservoir multiplugs and
pipes, secure pipes with clips.
35.Secure fog lamp multiplug.
36.Secure earth header behind headlamp.
37.Connect multiplugs to headlamp level motor,
headlamp and side lamp.
38.Fit indicator lamp

+ LIGHTING, REPAIRS, Lamp - front
repeater - up to 03MY.
39.Connect multiplug to LH horn.
40.Feed harness to ACE accelerometer, connect
multiplug and secure with cable ties.
41.Connect cruise control, ABS sensor and brake
fluid level switch multiplugs.
42.Connect engine harness multiplug and feed
harness along RH wing to fuse box.
43.Using draw string pull harness through inner
wing, remove draw string, connect repeater
lamp multiplug and fit lamp.
44.Connect chassis harness multiplugs.
45.Position engine bay fuse box and connect
multiplugs, fit fuse box and secure with screws.
46.Connect multiplugs to front of fuse box.
47.Position battery and starter cables and secure
with screws.
48.Fit fuse box cover.
49.Position earth lead and secure with nut.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-1
INS TRUMENTS DESCRIPTION AND OPERAT ION
Instrument pack
1Hill descent control information warning lamp
2Overspeed warning lamp
3Brake system warning lamp
4Malfunction Indicator Lamp (MIL)
5Tachometer
6Direction indicator warning lamp
7Main beam warning lamp
8Direction indicator warning lamp
9Speedometer
10SRS warning lamp
11Off road mode warning lamp
12Glow plug warning lamp
13Trailer warning lamp
14Water in fuel filter warning lamp
15Transmission high temperature warning lamp
16Seat belt warning lamp17Fuel tank level gauge
18Low fuel level warning lamp
19LCD odometer/trip meter
20Anti-theft status warning lamp
21ABS warning lamp
22Gearbox manual/sport mode warning lamp
23Alternator charge warning lamp
24ACE warning lamp
25Oil pressure warning lamp
26SLS warning lamp
27Hill descent control warning lamp
28Engine coolant temperature gauge
29High coolant temperature warning lamp
30Traction control warning lamp
31Differential lock warning lamp
32Transfer box neutral warning lamp