battery LAND ROVER DISCOVERY 1999 Workshop Manual

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.

RESTRAINT SYSTEMS
REPAIRS 75-19
Pre-tensioner - seat belt - front -
deployment - in vehicle
$% 76.73.77
These guidelines are written to aid authorised
personnel to carry out the safe disposal of air bag
modules when removed from the vehicle.
Deploy
It is imperative that before any work is
undertaken on the SRS system, the
appropriate information is read thoroughly.
1.Position front seat fully rearwards to access
seat belt pre-tensioner multiplug.
2.Make the SRS system safe.

+ GENERAL INFORMATION,
Supplementary Restraint System
Precautions.
3.Disconnect multiplug from seat belt pre-
tensioner.
4.Check condition of deployment tool LRT-86-
003 and associated fly leads.5.Connect deployment tool fly lead LRT-86-003/
04 to seat belt pre-tensioner.
6.Connect deployment tool LRT-86-003 to
deployment tool fly lead LRT-86-003/04.
7.Connect deployment tool LRT-86-003 to
battery.
WARNING: Ensure all personnel are at least
15 metres (50 feet) away from the air bag
module.
8.Press deployment tool operating button to
deploy seat belt pre-tensioner.
9.Disconnect deployment tool from battery.
WARNING: During deployment parts of the
air bag module become hot enough to burn
you. Wait 30 minutes after deployment
before touching the air bag module.
10.Disconnect deployment tool fly lead from seat
belt pre-tensioner.
11. Do not re-use or salvage any parts of the
SRS system.
NOTE: Do not transport deployed SRS
components in the vehicle passenger
compartment.

RESTRAINT SYSTEMS
REPAIRS 75-21
4.Connect deployment tool fly lead LRT-86-003/
04 to seat belt pre-tensioner.
5.Connect deployment tool LRT-86-003 to
deployment tool fly lead LRT-86-003/04.
6.Connect deployment tool LRT-86-003 to
battery.
7.Press deployment tool operating button to
deploy seat belt pre-tensioner.
WARNING: Ensure all personnel are at least
15 metres (50 feet) away from the air bag
module.
8.
9.Disconnect deployment tool from battery.
WARNING: During deployment parts of the
air bag module become hot enough to burn
you. Wait 30 minutes after deployment
before touching the air bag module.
10.Disconnect deployment tool fly lead from seat
belt pre-tensioner.
11.Remove seat belt pre-tensioner from holding
tool and place in a sealed bag, ready for
disposal.
NOTE: Do not transport deployed SRS
components in the vehicle passenger
compartment.12.Wipe down holding tools with a damp cloth and
remove from vice.
13.Transport deployed seat belt pre-tensioner to
designated area for incineration.
14. Do not re-use or salvage any parts of the
SRS system.

RESTRAINT SYSTEMS
75-22 REPAIRS
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 air bag module
to steering wheel.
3.Release air bag module from steering wheel.
CAUTION: Do not allow the air bag module
to hang by the air bag harness.
4.Disconnect multiplug from air bag module. 5.Remove air bag 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 air bag module and connect multiplug.
2.Fit air bag module to steering wheel and tighten
Torx bolts to 9 Nm (7 lbf.ft).
3.Connect battery leads, earth lead last.

RESTRAINT SYSTEMS
REPAIRS 75-23
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 air bag
module.4.Disconnect multiplug from air bag module.
5.Remove 4 Torx bolts securing air bag module
to fascia.
6.Remove air bag module from fascia panel.
WARNING: Store the air bag module with
the deployment side uppermost. If it is
stored deployment side down, accidental
deployment will propel the air bag module
with enough force to cause serious injury.
WARNING: Store the air bag 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 air bag module is to be replaced,
the bar code of the new module must be
recorded.
1.Fit air bag module to fascia and tighten Torx
bolts to 8 Nm (6 lbf.ft).
2.Connect multiplug to air bag module.
3.Position glove box and engage supporting
guides. Close glove box.
4.Connect battery leads, earth lead last.

RESTRAINT SYSTEMS
75-24 REPAIRS
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.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.

RESTRAINT SYSTEMS
REPAIRS 75-25
Air bag - steering wheel - deployment -
off vehicle
$% 76.74.16
These guidelines are written to aid authorised
personnel to carry out the safe disposal of air bag
modules when removed from the vehicle.
Deploy
It is imperative that before any work is
undertaken on the SRS system, the
appropriate information is read thoroughly.
1.Check condition of deployment tool LRT-86-
003 and associated fly leads.
2.Position LRT-86-007/02 in vice, ensuring that
vice jaws grip tool above the bottom flange to
prevent possibility of tool being forced upwards
during detonation. Tighten vice.
3.Fit and secure 2 off LRT-86-007/05 to LRT-86-
007/02.4.Fit and secure air bag to LRT-86-007/05.
5.Connect deployment tool fly lead LRT-86-003/
08 to air bag.
6.Connect deployment tool LRT-86-003 to
deployment tool fly lead LRT-86-003/08.
7.Connect deployment tool LRT-86-003 to
battery.
WARNING: Ensure all personnel are at least
15 metres (50 feet) away from the air bag
module.
8.Press deployment tool operating button to
deploy air bag module.
9.Disconnect deployment tool from battery.
WARNING: During deployment parts of the
air bag module become hot enough to burn
you. Wait 30 minutes after deployment
before touching the air bag module.
10.Disconnect deployment tool fly lead from air
bag.
11.Remove air bag module from holding tools and
place in a sealed bag, ready for disposal.
NOTE: Do not transport deployed SRS
components in the vehicle passenger
compartment.
12.Wipe down holding tools with a damp cloth and
remove from vice.
13.Transport deployed air bag module to
designated area for incineration.
14. Do not re-use or salvage any parts of the
SRS system.

RESTRAINT SYSTEMS
REPAIRS 75-27
6.Connect deployment tool fly lead LRT-86-003/
04 to air bag.
7.Connect deployment tool LRT-86-003 to
deployment tool fly lead LRT-86-003/04.
8.Connect deployment tool LRT-86-003 to
battery.
WARNING: Ensure all personnel are at least
15 metres (50 feet) away from the air bag
module.
9.Press deployment tool operating button to
deploy air bag module.
10.Disconnect deployment tool from battery.
WARNING: During deployment parts of the
air bag module become hot enough to burn
you. Wait 30 minutes after deployment
before touching the air bag module.
11.Disconnect deployment tool fly lead from air
bag.
12. Do not re-use or salvage any parts of the
SRS system.
NOTE: Do not transport deployed SRS
components in the vehicle passenger
compartment.
Air bag - fascia - passenger - deployment
- off vehicle
$% 76.74.18
These guidelines are written to aid authorised
personnel to carry out the safe disposal of air bag
modules when removed from the vehicle.
Deploy
It is imperative that before any work is
undertaken on the SRS system, the
appropriate information is read thoroughly.
1.Check condition of deployment tool LRT-86-
003 and associated fly leads.
2.Position LRT-86-007/03 in vice, ensuring that
vice jaws grip tool above the bottom flange to
prevent possibility of tool being forced upwards
during detonation. Tighten vice.
3.Fit and secure 2 off LRT-86-007/04 to LRT-86-
007/03.

RESTRAINT SYSTEMS
75-28 REPAIRS
4.Fit and secure air bag to LRT-86-007/04.
5.Connect deployment tool fly lead LRT-86-003/
08 to air bag.
6.Connect deployment tool LRT-86-003 to
deployment tool fly lead LRT-86-003/08.
7.Connect deployment tool LRT-86-003 to
battery.
WARNING: Ensure all personnel are at least
15 metres (50 feet) away from the air bag
module.
8.Press deployment tool operating button to
deploy air bag module.
9.Disconnect deployment tool from battery.
WARNING: During deployment parts of the
air bag module become hot enough to burn
you. Wait 30 minutes after deployment
before touching the air bag module.
10.Disconnect deployment tool fly lead from air
bag.
11.Remove air bag module from holding tools and
place in a sealed bag, ready for disposal.
NOTE: Do not transport deployed SRS
components in the vehicle passenger
compartment.
12.Wipe down holding tools with a damp cloth and
remove from vice.
13.Transport deployed air bag module to
designated area for incineration.
14. Do not re-use or salvage any parts of the
SRS system.
M76 4621
LRT-86-007/04
LRT-86-003/08
LRT-86-003