1995 LAND ROVER DISCOVERY electrical

70BRAKES
20
REPAIR STOP LIGHT SWITCH - NON ABS
Service repair no - 86.65.51
Remove
1.Disconnect battery negative lead.
2.Remove lower dash panel.
3.Depress foot brake.
4.Remove rubber protector from switch, if fitted.
5.Remove hexagon nut.
6.Withdraw switch.
7.Disconnect electrical leads.
Adjust
8.With switch still in position and multiplug
disconnected, connect an ohmmeter across
switch terminals.
9.Screw switch in until open circuit exists across
terminals with pedal released and continuity
exists as soon as pedal is depressed.
10.Tighten locknut.
CAUTION: Ensure switch does not prevent
brake pedal returning fully.
Refit
11.Reverse removal procedure.

BRAKES
21
REPAIR BRAKE COMPONENTS ABS
Left hand drive shown. On right hand drive vehicles the master cylinder and servo unit only move
position.
KEY
1. Connector-double elbow
2. Rear left brake
3. Modulator to rear left brake
4. Modulator to master cylinder
5. Modulator to pressure reducing valve upper
6. Electrical connection
7. Modulator unit
8. Nut, mounting bush and cup
9. Modulator to front left brake
10. Front left brake
11. Electrical connection12. Modulator to front right brake
13. Modulator to pressure reducing valve lower
14. Master cylinder to pressure reducing valve lower
15. Front right brake
16. Bolt
17. Pressure reducing valve
18. Modulator to pressure reducing valve upper
19. Master cylinder
20. Servo unit
21. Modulator to rear right brake
22. Rear right brake

70BRAKES
22
REPAIR MODULATOR UNIT
Service repair no - 70.65.45
WARNING: New modulator units are
supplied in a shock absorbing pack
marked with a use by date. The new
modulator will contain hydraulic brake fluid within
the valve block and all ports plugged.
Modulator units must be handled with care the
following must be avoided:- any impact, use of
compressed air on any of the hydraulic ports,
removing plugs to connection ports before fitting
unit.
Remove
1.Refer to the illustration of brake components
ABS. For details of modulator unit and hydraulic
pipe connections to it.
See Brake
Components ABS
2.Refer to general brake service practice.See
General Brake Service Practice
3.Check new modulator unit is packaged in
accordance with the WARNING above.
4.Disconnect battery negative lead.
5.Remove the two electrical plugs.
6.Identify 8 pipe to modulator connections for
correct reassembly.
7.Disconnect 8 pipe unions.
8.Remove nuts securing modulator to mounting
bracket.
9.Remove modulator unit.
10.Remove mounting bushes and cup.
Refit
11.Fit mounting bushes and cup to new modulator.
12.Fit modulator unit to mounting bracket.
13.Fit 8 pipes to modulator connections. Pipes
mustbe connected to correct port. Tighten to
15Nm.
14.Bleed the complete hydraulic system.See
Brake System Bleed
15.Check system function using the 'Testbook'
diagnostics
16.Test operation of brakes.ELECTRONIC CONTROL UNIT ABS
Service repair no - 70.65.01
Remove
For location of the ECU.
See Description and
operation, ABS Components
1.Disconnect battery negative lead.
2.Remove retaining bolt and lower alarm system
ECU and relay mounting bracket into passenger
footwell.
3.Remove two screws and detach ECU complete
with harness plug from mounting bracket.
4.Release ECU plug retaining clip.
5.Move plug in direction of arrow and release
hooked end of plug from retaining post.
Refit
6.Reconnect ECU harness plug ensuring that it is
firmly located and retaining clip secures plug.
7.Reverse removal procedure.

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
5
DESCRIPTION AND OPERATION
7.Do not use electrical test equipment on the
airbag harness or connectors. Tampering with or
disconnecting the harness could result in
accidental firing of the airbag or make the
system inoperative, which may result in serious
injury.
8. An airbag system fault can only be
diagnosed using TestBook.
9.The airbag module contains Sodium Azide which
is poisonous and extremely flammable. Contact
with water, acid or heavy metals may produce
harmful or explosive compounds. Do not
dismantle, incinerate or bring into contact with
electricity.VEHICLE RECOVERY
Towing - airbag not deployed
Normal towing procedures are unlikely to cause an
airbag to deploy. However, as a precaution switch the
ignition off and then disconnect both battery leads.
Disconnect the negative '-' lead first.
Towing - airbag deployed
Once the driver's airbag has been deployed the
vehicle must have a front suspended tow. However,
as a precaution switch the ignition off and then
disconnect both battery leads. Disconnect the
negative '-' lead first.

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.

SUPPLEMENTARY RESTRAINT SYSTEM
3
FAULT DIAGNOSIS
4.Airbag modules
A- If defective, replace and dispose of the entire unit
as directed in the instructions. Under no
circumstances should a diagnosis be performed using
electrically powered test equipment or probing
devices.
B- Tampering or mishandling can result in personal
injury. For special handling instruction refer to the
Workshop manual. This airbag module cannot be
repaired. Use diagnostic instructions to determine if
the unit is defective.
C- ROVER Bar code - The code number must be
recorded if the airbag module is to be replaced.
5.Steering wheel
Refer to the Owner's Handbook for information
on the airbag system.

SUPPLEMENTARY RESTRAINT SYSTEM
7
REPAIR ROTARY COUPLER CENTRALISE
Fitting a rotary coupler which has not been centralised
could result in tape breakage. If the tape is broken, a
new rotary coupler must be fitted.
Providing the removal procedure has been correctly
followed this operation should not be necessary. If
however there is evidence of tampering, it is
imperative that the coupler is centralised.
CAUTION: Ensure wheels are positioned
straight ahead before fitting the rotary
coupler.
1.Correctly fit rotary coupler to column switch
assembly but do not fit steering wheel or make
any electrical connections.
See rotary coupler.
2.Depress rotary coupler locking peg and without
using undue force, rotate coupler anti-clockwise
as far as inner tape will allow. Releasing peg will
lock coupler in its current position.
NOTE: Do not apply excessive force when
limit is reached as this may result in tape
breakage. If no limit can be found, tape
has already broken and rotary coupler must be
replaced.
3.Having turned rotary coupler fully anti-clockwise
to limit position, proceed to turn coupler 2.5 turns
clockwise to obtain central position. (Coupler will
normally rotate a full five turns from
anti-clockwise limit to clockwise limit).
4.Make necessary electrical connections and refit
steering wheel.
See steering wheel.
5.Refit driver's airbag module.See driver's
airbag module.
COLUMN SWITCH ASSEMBLY
Service repair no - Indicator/lighting - 86.65.55
Service repair no - Wash/wipe - 84.15.34
Remove
1.Remove steering wheel.
See steering wheel.
2.Release 2 turnbuckles and remove lower dash
panel.