2002 LAND ROVER DISCOVERY battery

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.

RESTRAINT SYSTEMS
75-6 DESCRIPTION AND OPERATION
Seat belt pretensioners
The seat belt pretensioners are located within the front seat belt anchors and are controlled by the DCU. They are
pyrotechnic devices that, when deployed, tighten the front seat belts. This works in conjunction with the airbag
module(s) to protect front seat occupants in the event of an accident.
The DCU regularly applies a test current to the seat belt pretensioner squibs 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 squibs. 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.

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.

RESTRAINT SYSTEMS
75-22 REPAIRS
4.Release rotary coupler multiplug from bracket
and disconnect from harness.
5.Disconnect rotary coupler multiplug from
harness.
6.Remove rotary coupler.
Refit
1.Fit rotary coupler to steering column and
connect multiplug to harness.
2.Connect rotary coupler multiplug to harness
and secure to bracket.
3.Fit steering column nacelle.

+ STEERING, REPAIRS, Nacelle -
steering column.
4.Fit steering wheel.

+ STEERING, REPAIRS, Steering
wheel.
Airbag deployment tool - self test
$% 76.74.99
Test
1.Insert BLUE and YELLOW connectors of tool
lead into corresponding sockets on face of tool.
2.Connect crocodile clips of second tool lead to
battery, RED to positive and BLACK to
negative.
3.RED "READY" light should illuminate.
4.Press and hold both operating buttons.
5.GREEN "DEFECTIVE" light should illuminate.
6.Release both operating buttons.
7.RED "READY" light should illuminate.
8.Disconnect tool from battery.
9.Disconnect blue and yellow connectors from
tool face sockets.
10.Self test now complete.

RESTRAINT SYSTEMS
75-24 REPAIRS
5.Ensure airbag module mounting brackets are
secure.
6.Connect flylead SMD 4082/4 to airbag module.
WARNING: Ensure the deployment tool is
not connected to the battery.
7.Connect flylead SMD 4082/4 to tool SMD 4082/
1.
WARNING: Do not lean over module whilst
connecting.
8.Connect tool SMD 4082/1 to battery.
WARNING: Ensure all personnel are at least
15 metres (50 ft) away from the airbag
module.9.Press both operating buttons to deploy airbag
module.
10.DO NOT return to airbag module for 30
minutes.
11.Using gloves and face mask, remove airbag
module from tool, place airbag module in
plastic bag and seal bag.
12.Wipe down tool with damp cloth.
13.Transport deployed airbag module to
designated area for incineration.
NOTE: DO NOT re-use or salvage any parts of
the airbag system including steering wheel or
steering column. Do not transport deployed
SRS components in the vehicle passenger
compartment.