sensor LAND ROVER DISCOVERY 1995 Workshop Manual

70BRAKES
18
REPAIR SENSORS - FRONT
Service repair no - 70.65.32
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush and seal must
be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect required sensor electrical
connection, located on inner wing [fender] panel.
3.Remove sensor lead from clips.
4.Clean area surrounding sensor to prevent
ingress of dirt. Using a suitable lever pry sensor
from mounting bush.
5.Release harness cable ties, remove sensor lead
from vehicle.
6.Remove top swivel retaining bolts complete with
brake jump hose and sensor seal. Remove
sensor bush.
Refit
7.Insert new sensor bush and seal.
8.Refit brake jump hose bracket, coat bolts with
Loctite 270.
9.Lightly coat new sensor using EP 90 oil. Push
sensor through bush until it contacts exciter ring.
Sensor will be 'knocked back' to correct position
when vehicle is driven.
10.Secure sensor lead in original position.
11.Reconnect sensor electrical connection.
12.Drive vehicle to ensure ABS warning light is
extinguished.
SENSOR RINGS
The rear sensor ring is assembled to the rear brake
disc to form part of the rear hub assembly.
See
REAR AXLE AND FINAL DRIVE, Repair, Rear Hub
Assembly
The front sensor ring is a toothed ring on the axle
shaft which forms part of the front stub axle assembly.
See FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS

BRAKES
19
REPAIR SENSORS - REAR
Service repair no - 70.65.31
CAUTION: If a sensor is removed for any
reason, a NEW sensor bush must be fitted.
Remove
1.Disconnect battery negative lead.
2.Disconnect sensor electrical connections,
located above rear axle.
3.Remove sensor from its locating clip.
4.Remove bolts securing mudshield.
5.Using a suitable lever, pry sensor from mounting
bush.
6.Release harness cable ties, remove sensor lead
from vehicle.
7.Remove sensor bush.
Refit
8.Fit new sensor bush.
9.Lightly grease new sensor using silicone grease.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
10.Push sensor through bush until it touches exciter
ring. Sensor will be 'knocked back' to correct
position when vehicle is driven.
11.Secure harness in position.
12.Reconnect sensor electrical connection.
13.Drive vehicle to ensure ABS warning light is
extinguished.STOP LIGHT SWITCH ABS
Service repair no - 86.65.51
Remove
1.Turn ignition off. Disconnect battery negative
lead.
2.Remove lower trim panel.
3.Disconnect multiplug to switch.
4.Depress brake pedal access front of switch.
5.Pull sleeve and plunger of switch FULLY
forward.
6.Remove switch rearwards
NOTE: If switch is difficult to release,
check sleeve is FULLY forward.
Refit
7.Pull sleeve and plunger of switch fully forward.
8.Depress brake pedal, fit switch. Ensure retaining
clips are FULLY located.
9.Hold switch firmly in place, pull brake pedal back
fully to set switch.
10.Reconnect battery and turn ignition on.
11.Check switch operation by slowly depressing
brake pedal and checking that the switch clicks
twice.
12.Check stop lamps go off when pedal is released.
13.Recheck switch is securely fitted.
14.Operation may be checked using Testbook.

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.

SUPPLEMENTARY RESTRAINT SYSTEM
1
FAULT DIAGNOSIS CRASH SENSOR INSPECTION - DISTRIBUTED
SRS
1.After any degree of front body damage, inspect
both front crash sensors. Replace a sensor if
there are any signs of dents, cracks or
deformation.
2.Ensure the sensors are installed correctly. There
must be no gap between the sensor and body of
the vehicle. Use the fixing screws supplied with
the sensor and tighten to the correct torque.
Tighten front sensor fixing before rear sensor
fixing.
CAUTION: Take extra care when painting
or doing body work in the vicinity of the
sensors. Avoid direct exposure of the
sensors or harness to heat guns, welding or
spraying equipment.AIRBAG HARNESS
1.Never attempt to modify, splice or repair the
airbag harness. Never install electronic
equipment such as; a mobile telephone, two-way
radio or in-car entertainment system in such a
way that it interferes electrically with the airbag
harness.
NOTE: The airbag harness can be
identified by a special yellow outer
protective covering.
2.Make sure the airbag harness is installed
correctly and not pinched or trapped.
3.Ensure all airbag harness connectors are mated
correctly and securely fastened. Do not leave the
connectors hanging loose.

75SUPPLEMENTARY RESTRAINT SYSTEM
10
REPAIR CRASH SENSOR - DISTRIBUTED SRS
Service repair no - 76.74.04
Remove
1.Disconnect battery negative lead.
2. LH sensor only:Slacken power steering
reservoir clamp and lift reservoir to provide
access.
Diesel model only:Remove jack and mounting
bracket.
3.Disconnect multiplug from sensor
CAUTION: Ensure airbag harness
connector seal and anti-backout DO NOT
come adrift when disconnecting sensor.
4.Use special socket, remove 2 screws securing
crash sensor to body.
5.Remove crash sensor.Refit
6.Reverse removal procedure.
7.Tighten crash sensor securing screws to
10 Nm
(7 lbf ft).
Ensure multiplug is fully engaged on
sensor and retained by its latch.
8.Check Supplementary Restraint System using
Testbook.

75SUPPLEMENTARY RESTRAINT SYSTEM
14
REPAIR AIRBAG HARNESS
Service repair no - 86.70.63
Remove
1.Remove driver's airbag.
See driver's airbag
module.
2.Remove passenger's airbag.See passenger's
airbag module.
3.Remove dash panel assembly.See CHASSIS
AND BODY, Repair, dash panel assembly
4.Remove heater blower unit.See HEATING
AND VENTILATION, Repair, blower motor
unit - heater and air conditioning.
5.Remove heater and cooler unit.See AIR
CONDITIONING, Repair, heater and cooler
unit
Pre 97 MY
6.Remove 3 screws securing expansion tank and
position expansion tank aside.
7.Disconnect multiplug from each crash sensor.
8.Release airbag harness from clips and ties along
the bulkhead and each valance.
9.Displace airbag harness grommet to inside of
bulkhead and feed harness through bulkhead.
All Models
10.Disconnect multiplug from airbag control unit.
11.Release airbag harness from under carpet.
12.Release ties securing harness along toeboard.
13.Disconnect steering wheel airbag multiplug.
14.Release airbag harness from driver's side and
remove.
Refit
15.Reverse removal procedure.
CAUTION: Ensure harness is correctly
routed in harness protector and that all
securing clips and ties are correctly
engaged and harness is undamaged. Ensure all
connections are fully engaged and retained by
their latches.

SUPPLEMENTARY RESTRAINT SYSTEM
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Airbag module screws 8 (6 lbf ft)...........................................................................
Steering wheel nut 50 (37 lbf ft)..............................................................................
Crash sensor screws (Distributed SRS) 10 (7 lbf ft)..............................................
Control unit 10 (7 lbf ft)...........................................................................................

76CHASSIS AND BODY
68
REPAIR Dismantle
4.Remove interior lamp lens.
5.Remove 2 nuts securing lamp to stowage panel.
6.Remove lamp.
7.Remove alarm volumetric sensor/blanking plate.
8.Remove electric sun roof switch pack.
9.Remove electric sun roof manual opening plug.
Rebuild
10.Fit electric sun roof manual opening plug to
panel.
11.Fit alarm volumetric sensor.
12.Fit electric sun roof switch pack to panel.
13.Fit interior lamp to panel and secure with nuts.
14.Fit interior lamp lens.
Refit
15.Position stowage panel assembly and connect
Lucar and multiplugs.
16.Align panel to headlining and secure with
screws.REAR FOLD DOWN SEAT BELTS - LH WITH REAR
AIR CONDITIONING FITTED
Service repair no - 76.73.28/20
Remove
1.Locate the seat in the down position, remove the
seat belt strap and buckle from their stowed
positions.
2.Remove seat belt strap and buckle retaining bolt
covers.
3.Remove bolts securing strap and buckle.
4.Remove seat belts and collect spacers.
Refit
5.Fit spacers to seat belt retaining bolts, position to
fixings and tighten to
32 Nm (24 lbf ft).
6.Fit seat belt retaining bolt covers.
7.Secure seat belt strap and buckle to their stowed
positions and position seat in the up position.