glove box LAND ROVER DISCOVERY 2002 Workshop Manual
Page 951 of 1672
FRONT SUSPENSION
60-12 DESCRIPTION AND OPERATION
ACE system
aDirection of travel - Right hand bend
bBody roll
cAxle roll
dTyre squash
eTorsion/Anti-roll bar
fDirection of torsion/anti-roll bar twist
gCoil springs
hBody roll angle
iAxle roll angle
jReduced body roll angle with ACE system
The system is electrically and hydraulically operated with all operations controlled by an ACE ECU located behind the
glovebox in the passenger side footwell. The ACE system comprises front and rear torsion bars and actuators, two
accelerometers, ECU, hydraulic pump, valve block and a fluid reservoir.
The ACE system gives improved vehicle handling and suspension characteristics and is active for both on and off-
road driving. This is achieved by hydraulic actuators applying torque to the front and rear torsion bars in response to
lateral forces sensed by accelerometers. The ACE system prevents body roll with cornering forces of up to 0.4 g. From
0.4 g there is a progressive increase in body roll but significantly lower than a passive system. A passive system will
have a progressive increase in roll angle as soon as cornering forces are applied and will have a higher roll angle than
the ACE system for the same cornering force.
The ACE system can also detect if the vehicle is driven off-road. If off-road conditions are detected the ACE system
operation will be reduced or completely disabled at a speed of 25 mph (40 km/h) or less.
Page 959 of 1672
FRONT SUSPENSION
60-20 DESCRIPTION AND OPERATION
ACE Electronic control unit (ECU)
1Body Control Unit (Ref. only)
2Bracket
3ACE 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.
Page 1022 of 1672
REAR SUSPENSION
DESCRIPTION AND OPERATION 64-17
SLABS ECU
1SLABS ECU
2Bracket
3BCU (Ref. only)
4ACE ECU (Ref. only)
5Attachment nuts
The SLABS ECU is mounted on a bracket behind the passenger glove box and is identified from the other ECU's by
its five connectors. The five connectors are located on the lower face of the ECU and mate with five connectors from
the main harness. The twelve, six and eighteen pin connectors are used to supply inputs and outputs to and from the
ECU. The remaining connectors are used for the ABS operation.
+ BRAKES, DESCRIPTION AND OPERATION, Description.
The SLABS ECU receives a continuous battery supply from fuse 11 in the engine compartment fusebox. An ignition
'ON' signal is supplied from the ignition switch via fuse 28 in the passenger compartment fusebox. The ECU has the
ability to control when it requires power and is not reliant on the ignition signal for it to power up.
The ECU incorporates a counter which times the operation of the SLS system and prevents the compressor
exceeding its duty cycle. The ECU can remain powered for up to 1.5 hours after ignition off is sensed to allow the
counter to continue running to avoid an ignition cycle resetting the counter.
Opening any of the doors will power up the ECU, irrespective of ignition switch position. The door open signal is
sensed by the door switch completing an earth path which is sensed by the ECU. The ECU cannot differentiate
between any of the doors. The door open signal powers the ECU for up to 30 minutes to allow the vehicle to re-level
when a load is removed or passengers leave the vehicle.
Page 1062 of 1672
BRAKES
DESCRIPTION AND OPERATION 70-17
SLABS ECU
The SLABS ECU is attached to a bracket behind the front passenger glovebox. Brake related inputs are processed
by the SLABS ECU, which then outputs control signals to the ABS modulator. Five electrical connectors interface the
SLABS ECU with the vehicle wiring.
SLABS ECU connector pin details
Connector/Pin No. Description Input/Output
C0504
1 Battery supply Input
2 Ignition supply Input
3 Road speed Output
4 Rough road (V8 models only) Output
5 K line (diagnostics) Input/Output
7 Reverse gear Input
8 Return pump monitor Input
9 Brake warning lamp Output
10 Engine data (throttle position, torque, engine type, gearbox type) Input
11 Transfer box range Input
12 Earth-
13 ETC warning lamp Output
14 HDC switch Input
15 Neutral selected (automatic gearbox only) Input
16 HDC fault warning lamp Output
17 HDC information warning lamp Output
18 ABS warning lamp Output
C0505
1 Front left wheel speed Input
2 Front left wheel speed Input
3 Rear right wheel speed Input
4 Front right wheel speed Input
5 Front right wheel speed Input
6 Rear right wheel speed Input
7 Rear left wheel speed Input
8 Rear left wheel speed Input
C0506
1 Front left outlet solenoid valve Output
2 Front left inlet solenoid valve Output
3Earth-
4 Front right outlet solenoid valve Output
5 Front right inlet solenoid valve Output
Page 1100 of 1672
RESTRAINT SYSTEMS
DESCRIPTION AND OPERATION 75-5
Passenger airbag module
The passenger airbag module is located in the instrument panel above the glove box and is controlled by the DCU.
A bag within the module inflates to protect the passenger in the event of a collision severe enough to deploy the
system.
Within the passenger airbag module is a squib which, when given the correct current by the DCU, inflates the airbag
by initiating a chemical reaction. In deployment, the airbag inflates within a fraction of a second and then deflates at
a controlled rate as the weight of the passenger presses against the bag. Vents in the bag control airbag deflation.
The DCU regularly applies a test current to the passenger airbag squib to confirm continuity of the ignition circuitry.
The DCU is capable of detecting a short to ground, a short to battery and an open circuit for the passenger airbag
module squib. It will also identify if the configuration of the DCU differs from that actually fitted to the vehicle.
The DCU also stores the following additional information on each fault:
lA count indicating the number of times the fault has occurred.
lA start time and an end time for the fault to indicate duration of the fault.
Page 1114 of 1672
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.
Page 1115 of 1672
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.
Page 1163 of 1672
INTERIOR TRIM COMPONENTS
76-3-10 REPAIRS
7.Remove 6 clips securing both lower closing
panels to fascia and remove closing panels.
8.Remove mats from fascia.
9.Remove 2 screws and release instrument cowl
from 2 clips on fascia.
10.Disconnect multiplugs from switches in
instrument cowl and remove cowl.
11.Remove 4 screws securing instrument pack to
fascia.
12.Disconnect 2 multiplugs from instrument pack
and remove pack. 13.Remove fascia access panel.
+ INTERIOR TRIM COMPONENTS,
REPAIRS, Panel - fascia access - driver's
side.
14.Remove 4 nuts securing fascia to steering
column bracket.
15.Disconnect 3 multiplugs connecting main body
harness to fascia harness.
16.Disconnect fascia harness multiplug from fuse
box.
17.Remove 4 bolts securing glove box and remove
glove box.
Page 1164 of 1672
INTERIOR TRIM COMPONENTS
REPAIRS 76-3-11
18. Models with A/C: Disconnect multiplug from
heater controls.
19. Models without A/C: Release temperature
and air distribution control outer cables from
clips on heater casing and disconnect inner
cables from levers.20.Separate blue section from ICE multiplug.
21.Release coaxial cables from fascia panel.
22.Disconnect multiplug from passenger air bag.
23.Disconnect multiplug from blower motor.
24.Working through glove box aperture remove 2
bolts, or 4 bolts if passenger airbag module is
fitted, securing fascia to body.
Page 1165 of 1672
INTERIOR TRIM COMPONENTS
76-3-12 REPAIRS
25.Remove 4 bolts securing lower edge of fascia
to mounting brackets on transmission tunnel.
26.Remove 4 bolts securing lower edge of fascia
to brackets on 'A' post.
27.With assistance carefully remove fascia from
vehicle.
28.If renewing fascia, transfer components to new
fascia as necessary.
Refit
1.With assistance carefully fit fascia and tighten
bolts securing lower edge of fascia to 26 Nm
(19 lbf.ft).
2.Tighten bolts securing fascia to body to 26 Nm
(19 lbf.ft).
3.Fit nuts securingfascia to steering column
bracket to 11 Nm (8 lbf.ft).
4.Secure coaxial cables to fascia and secure blue
multiplug to main ICE multiplug.
5. Models with A/C: Connect heater control
multiplug.
6. Models without A/C: Connect temperature
and air distribution inner cables to heater
control levers. Set temperature control knobs to
fully hot, distribution knob to demist position
and, with flap levers fully closed, secure outer
cables to clips on heater casing.
7.Connect multiplugs to blower motor and
passenger air bag (where fitted).
8.Fit glove box and secure with bolts.
9.Connect fascia harness multiplugs to main
harness and fuse box.
10.Position instrument pack and connect
multiplugs.11.Fit instrument pack to fascia and secure with
screws.
12.Position instrument cowl and connect
multiplugs to switches.
13.Fit cowl to clips on fascia and secure with
screws.
14.Fit fascia access panel.
+ INTERIOR TRIM COMPONENTS,
REPAIRS, Panel - fascia access - driver's
side.
15.Fit fascia lower closing panels and secure with
clips.
16.Fit fascia mats.
17.Fit 'A' post trim panels.
18.Fit centre console
lFor models with automatic gearbox:
+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - automatic
models.
lFor models with manual gearbox:
+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
19.Fit steering column nacelle.
+ STEERING, REPAIRS, Nacelle -
steering column.
20.Fit steering wheel.
+ STEERING, REPAIRS, Steering
wheel.
21.Fit radio cassette player.
+ IN CAR ENTERTAINMENT,
REPAIRS, Radio cassette player.
22.Connect battery.