1995 LAND ROVER DISCOVERY warning

SUPPLEMENTARY RESTRAINT SYSTEM
1
DESCRIPTION AND OPERATION SYSTEM COMPONENTS
1. Airbag crash sensors (distributed SRS)
2. SRS warning light (airbag)
3. Rotary coupler
4. Driver's airbag module
5. Passenger's airbag module6. Airbag diagnostic socket
7. Airbag diagnostic control unit
8. Airbag harness (distributed SRS)
9. Knee bolsters (where fitted)
10. Airbag harness

75SUPPLEMENTARY RESTRAINT SYSTEM
2
DESCRIPTION AND OPERATION OPERATION
The airbag supplementary restraint system (SRS) is a
safety device which, when used in conjunction with
the seat belt, is designed to protect the driver and
front passenger.
Two different SRS systems are fitted to Discovery.
The Distributed SRS which has two crash sensors
located in the engine compartment on the chassis
longitudinals and the Single Point Sensing (SPS) SRS
which has a single crash sensor located in the Airbag
diagnostic control unit.
The change from distributed SRS to SPS SRS
occurred at VINs198222and528977.
Distributed SRS
In the event of a frontal impact, when the airbag
diagnostic control unit and one of the airbag crash
sensors senses the impact, the diagnostic control unit
fires igniters. This in turn ignites tablets of sodium
azide which generate a large amount of Nitrogen gas
leading to airbag inflation in approximately 30
milli-seconds.SPS SRS
In the event of a frontal impact, when the airbag
diagnostic control unit senses the impact, the
diagnostic control unit fires igniters. This in turn ignites
tablets of sodium azide which generate a large
amount of Nitrogen gas leading to airbag inflation in
approximately 30 milli-seconds.
All Models
When fully deployed the airbag offers additional
protection to the front seat occupant. As an occupant
moves into the airbag it immediately discharges the
gas to provide progressive occupant deceleration and
reduce risk of injuries. The whole process is
completed in approximately 0.3 seconds.
WARNING: All the airbag system
components, including the wiring harness,
MUST be renewed after the airbags have
deployed.

SUPPLEMENTARY RESTRAINT SYSTEM
3
DESCRIPTION AND OPERATION SRS warning light (airbag)
Distributed SRS
The warning light in the instrument pack illuminates
after the electrical circuits are switched on whilst a
system check is carried out. After about 8 seconds the
warning light will go out. The system checks airbag
diagnostic control unit, airbag crash sensors, airbag
harness, driver and passenger modules.
SPS SRS
The warning light in the instrument pack illuminates
after the electrical circuits are switched on whilst a
system check is carried out. After about 5 seconds the
warning light will go out. The system checks airbag
diagnostic control unit, airbag harness, driver and
passenger modules.
All Models
In the event of a fault in the system the warning light
will illuminate. The airbag diagnostic control unit logs
the fault which can only be accessed using TestBook.

75SUPPLEMENTARY RESTRAINT SYSTEM
6
DESCRIPTION AND OPERATION AIRBAG STORAGE
Temporary storage
For temporary storage of the airbag module during
service, observe the following precautions:
Store the airbag module with the pad surface up.
Place the airbag module in designated storage area.
If no designated storage area is available, the module
may be stored in the boot of the vehicle from which it
was removed. Always lock the boot when module is
stored in it and inform workshop supervisor.
WARNING: If the airbag is improperly
stored face down, accidental deployment
could propel the unit with enough force to
cause serious injury.
Store the removed airbag module on a secure flat
surface away from heat, oil, grease, detergent or
water.
CAUTION: Improper handling or storage
can internally damage the airbag module,
making it inoperative. If you suspect the
airbag module has been damaged, install a new
unit.
Overnight storage
Airbag modules are classed as an explosive article
and as such they must be stored in a secure steel
cabinet which has been approved by the local
authority.

75SUPPLEMENTARY RESTRAINT SYSTEM
2
FAULT DIAGNOSIS WARNING LABELS
1.Bonnet locking platform
Refer to the Owner's Handbook for information on the
airbag system.
2.Rotary coupler
CAUTION: Ensure wheels are straight
ahead before removal and installation.
3.Driver's sun visor
Refer to the Owner's Handbook for information on the
airbag system.

SUPPLEMENTARY RESTRAINT SYSTEM
1
REPAIR SYSTEM PRECAUTIONS
CAUTION: Before and during any removal
operations within the SRS section, note
routing and position of all harnesses to aid
correct refitting and to avoid accidentally trapping
cables.
CAUTION: During refitting of any item
within the SRS section, always ensure
connectors are fully engaged and latched
before proceeding to the next stage of the
operation.DRIVER'S AIRBAG MODULE
Service repair no - 76.74.01
WARNING: All the airbag system
components, including the wiring harness,
MUST be renewed after the airbags have
deployed.
Remove
1.Turn steering wheel 90Ê from horizontal.
2.Switch off ignition.
3.Disconnect battery negative '-' and then the
positive '+' lead.
CAUTION: Always disconnect both leads.
4.Release 2 turnbuckles and remove dash lower
panel.

SUPPLEMENTARY RESTRAINT SYSTEM
9
REPAIR PASSENGER'S AIRBAG MODULE
Service repair no - 76.74.02
WARNING: All the airbag system
components, including the wiring harness,
MUST be renewed after the airbags have
deployed.
Remove
1.Switch off ignition.
2.Disconnect battery negative lead and then
positive lead.
3.Open glovebox and disconnect harness
connector from airbag module.
4.Use special socket and long extension, remove
2 torx head screws securing front of airbag
module to fascia panel.
5.Use special socket, remove 2 torx head screws
securing rear of airbag module to fascia panel.
6.Release airbag module from fascia panel.
CAUTION: Do not allow the airbag module
to hang by the airbag harness.
7.Carefully and without pulling on connector
remove airbag module.
CAUTION: Store the airbag module in
accordance with the storage procedures
described in Description and Operation.
NOTE: If airbag module is to be replaced
the serial number must be recorded in the
vehicle service record.
Refit
8.Reverse removal procedure.
9.Tighten airbag module securing screws to
8Nm
(6 lbf ft).
CAUTION: Take care not to cross thread
screws.
10.Check Supplementary Restraint System using
Testbook.

75SUPPLEMENTARY RESTRAINT SYSTEM
12
REPAIR SRS WARNING LIGHT BULBS
Service repair no - 76.73.74
Remove
1.Remove instrument binnacle.
See
ELECTRICAL, Repair, instrument binnacle.
2.Remove window and face plate from instrument
panel.
3.Remove 3 screws securing ECU to instrument
panel.
4.Release and remove small cover from ECU.
5.Disconnect multiplug from ECU.
6.Remove ECU
7.Remove 4 screws securing tachometer.
8.Remove tachometer.