1995 LAND ROVER DISCOVERY fuses

04GENERAL SPECIFICATION DATA
14
INFORMATION Coil
Make/type Bosch 0221 122 392........................................................................
Distributor
Make/type Lucas 35 DLM8........................................................................
Firing angles 0°-45°-90°(every 45°)±1° ....................................................................
Application 12V Negative ground.......................................................................
Pick-up air gap adjustment
(Pick-up limb/reluctor tooth) 0.20 mm to 0.35 mm.............................................
Pick-up winding resistance 2k to 5k ohms...............................................
Fuses
Type Autofuse (blade type).................................................................................
blow ratings to suit individual circuits
Horns
Make/type Klamix (Mixo) TR99........................................................................
Starter motor
Make and type Bosch 12v.................................................................

19FUEL SYSTEM
6
DESCRIPTION AND OPERATION REV: 09/95 Idle air control (IAC)
Idle speed is controlled by a stepper motor which
consists of two coils. When energised in the correct
sequence the coils move a plunger which opens and
closes the throttle bypass controlling the quantity of
idle air. The stepper motor controls idle speed by
moving the plunger a set distance called a step. Fully
open is zero steps and fully closed 180 steps. Failure
of the stepper motor will result in low or high idle
speed, poor idle, engine stall or non start. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.Heated oxygen sensor (HO2S)
The oxygen sensors consist of a titanium metal
sensor surrounded by a gas permeable ceramic
coating. Oxygen in the exhaust gas diffuses through
the ceramic coating on the sensor, and reacts with the
titanium wire altering the resistance of the wire. From
this resistance change the ECM calculates the
amount of oxygen in the exhaust gas. The injected
fuel quantity is then adjusted to achieve the correct
air/fuel ratio, thus reducing the emissions of carbon
monoxide (CO), hydrocarbons (HC),and oxides of
nitrogen (NO
2). Two HO2 sensors are fitted, one in
each exhaust downpipe just ahead of the catalyst.
Note that if the wiring to these sensors is crossed, the
vehicle will start and idle correctly until the sensors
reach operating temperature. Then the ECM will read
the signals from them and send one bank of cylinders
very rich and the other very weak. The engine will
misfire, have a rough idle and emit black smoke, with
possible catalyst damage.
In the event of sensor failure, the system will default to
'open loop'. Operation and fuelling will be calculated
using signals from the remaining ECM inputs.
The fault is indicated by illumination of the malfunction
indicator light (MIL). ECM diagnostics also uses HO2
sensors to detect catalyst damage, misfire and fuel
system faults.
North American vehicles have two extra HO2 sensors
mounted one after each catalyst. These are used to
determine whether the catalysts are operating
efficently.
CAUTION: Although robust within the
vehicle environment, HO2 sensors are
easily damaged by dropping, excessive
heat and contamination. Care must be exercised
when working on the exhaust system not to
damage the sensor housing or tip.

BRAKES
3
DESCRIPTION AND OPERATION Description of components
1. ABS Modulator unit
To provide the ABS function a Modulator is positioned
within the system between the master cylinder and the
calipers. On both LHD and RHD vehicles it is sited on
the left inner wing [fender]. The Modulator has 8
solenoid valves, 2 for each wheel, 2 expanders and a
recirculation pump. It is non serviceable.
2. Servo/master cylinder
Actuation of the system is provided by a combined
master cylinder and servo assembly attached to the
pedal box, this provides pressure to opposed piston
calipers at each brake pad Twin piston at the front
axle, single piston at the rear.
3. Pressure reducing valve
To maintain the braking balance, pressure to the rear
axle is regulated by a Pressure Reducing Valve (PRV)
This PRV is of the failure bypass type, allowing full
system pressure to the rear axle in the event of a front
circuit failure. It is sited on the left inner wing [fender].
4. Electronic control unit - ECU
ABS control is provided by an electronic control unit
which is positioned on the passenger side of the
vehicle behind the dash panel/glove box.
The ECU, which is non-serviceable, is connected to
the ABS harness by a 35 way connector. non
serviceable.
The ECU continually monitors the brake system,
providing diagnostics in the event of a system
malfunction. Details of how to access the ECU
diagnostics are provided in the Electrical
Troubleshooting Manual.
5.& 6. Front and rear sensors/exciter rings - 4 off
A sensor is sited at each wheel, sensing a 60 tooth
exciter ring. When vehicle is in motion inductive
sensors send signals to ECU. Front exciter ring is
fitted to outside diameter of constant velocity joint
inside each front hub assembly. The rear exciter ring
is bolted to the rear of each brake disc bell.7. Diagnostic plug connection
A diagnostic plug is located behind the dash. To the
left of the steering column on LHD vehicles. To the
right of the steering column on RHD vehicles. It is a 5
way blue connector.
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual.
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment
ANTI-LOCK BRAKE SYSTEM - ABS
Manufactured by WABCO
Introduction
The purpose of ABS is to prevent vehicle wheels
locking during brake application, thus maintaining
vehicle steerability and stability. This allows vehicle to
be steered whilst brakes are applied, even under
emergency conditions, and to avoid obstacles where
there is sufficient space to redirect the vehicle.
WARNING: ABS is an aid to retaining
steering control and stability while
braking.
·ABS cannot defy the natural laws of physics
acting on the vehicle.
·ABS will not prevent accidents resulting from
excessive cornering speeds, following
another vehicle too closely or aquaplaning,
i.e. where a layer of water prevents adequate
contact between tyre and road surface.
·The additional control provided by ABS must
never be exploited in a dangerous or
reckless manner which could jeopardise the
safety of driver or other road users.
·The fitting of ABS does not imply that the
vehicle will always stop in a shorter stopping
distance.

70BRAKES
4
DESCRIPTION AND OPERATION System description
The brake system consists of dual hydraulic circuits in
a front - rear split. That is individual circuits to front
and rear axles.
Wheelspeed signals are provided by the fitting of
exciter rings to axles and speed sensors.
An ABS stop light switch is fitted to provide a braking
signal to the ECU as well as operate the stop lights.
Electrical wiring is provided as necessary with system
relays and fuses. Discovery Electrical Troubleshooting
Manual gives the location and wiring circuits of these
components.
Visual warning of system malfunction is provided via a
warning light in the instrument panel.
Hydraulic circuit ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve
D = ABS ModulatorABS System operation
During normal braking the feel of the brake pedal on
vehicles equipped with ABS will be the same as that
on non ABS vehicles. During ABS cycling the driver
will experience feedback in the form of a pulsating
brake pedal and solenoid/pump motor noise from the
Modulator.
The system is fully automatic in operation both on and
off road, and will only act when the ECU detects that
ABS cycling is necessary. The ECU continually
monitors the operation of the system.
When starting the ABS system will go through a series
of self checks, including a check of the solenoid
valves/pump motor.
WARNING LIGHT
The warning light will be on during the self check
(1.3-2 secs). If no faults are stored in the memory the
light goes out for 0.5sec,then comes on again. It will
then remain on until the vehicle is driven faster than 7
kph/5mph. This is the only time that the light will be on
without indicating a problem.
Any faults detected by the ECU will cause the warning
light to illuminate indicating that the vehicle may not
have full ABS control.

BRAKES
1
FAULT DIAGNOSIS ABS FAULT DIAGNOSIS
If a fault has occurred, or has been identified by ECU
self diagnostic function and ABS warning light is
illuminated. The system and components must be
checked to locate and rectify fault, using Testbook
diagnostics.
NOTE: If warning lamp has indicated a
fault in system, and no fault code has been
stored in memory, cause of fault is:
a) Failure in electrical supply
b) Bad ECU ground
c) Faulty warning light relay
d) ECU not connected
Before commencing fault diagnosis procedure
following items must be checked:
1.Inspect all exposed cables for damage or
abrasion.
2.Check ground on ABS system.
3.Battery - state of charge.
4.Check hub end-float.
5.All ABS fuses and electrical connections.
Fault rectification
1.Complete harness should be replaced if faults
are found in wiring harness.
2.DO NOT use unspecified cables or connectors,
as this could jeopardise safe function of ABS.
3.DO NOT attempt to open sealed 35 way
connector to ECU.FAULT DIAGNOSIS PROCEDURE
NOTE: If ABS warning light illuminates due
to large sensor air gap, fault will be
retained by the ECU memory. Where wheel
sensors have been pushed fully home prior to
test, The ECU will indicate a fault that has been
rectified.
NOTE: After any steering adjustment,
bearing replacement/adjustment, brake
disc replacement: Check hub end-float and
sensor clearance.
RELAYS AND FUSES ABS
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment

ELECTRICAL
1
REPAIR FUSE BOX - INTERIOR
Right Hand Drive shown
The interior fusebox is fitted below the steering column, behind the trim panel. It comprises of three integral units.
'A'Main fusebox,'B'Satellite 2,'C'Satellite 1.
A label in the fusebox cover shows the circuits protected, the fuse rating and their locations. Access is by
releasing the fixing screws and lowering the panel.
'A' Main fusebox
1. Stop lights, direction indicators
2. LH side light
3. Radio/cassette/CD player
4. RH headlight main beam
5. LH headlight main beam
6. Cigar lighter
7. Airbag SRS
8. RH side lights
9. Rear fog guard lights
10. RH headlight dipped beam
11. LH headlight dipped beam
12. Multi-function unit
13. Ignition feed for Multi-function unit
14. Instruments, reversing lights
15. Air conditioning, windows
16. Washers & wipers - front
17. Starter, glow plug
18. Wash/wipe - rear, mirrors, cruise control
'B' Satellite 2
1. Electric windows - front
2. Electric windows - rear
3. Anti-lock braking
4. Central door locking
5. Electric sun roof
6. Trailer lights
'C' Satellite 1
1. Anti-theft alarm
2. Headlight washers
3. Engine management
4. Anti-lock brakes
5. Anti-theft alarm
6. Rear air conditioning, heater
'D' Spare fuses (5 off)

86ELECTRICAL
2
REPAIR FUSE BOX - ENGINE COMPARTMENT
The fusebox is located on the right side of the engine compartment. The circuits protected and their locations are
shown on the inside of the fusebox cover. To change a main circuit fuse prise off protective cover A and remove
retaining screws.
Fuses
1. Heated rear window
2. Sidelights
3. Air conditioning
4. Hazard warning lights, horn
5. ABS valve
6. Fuel pump
7. Fuel injectors
A Main circuit fuses
8. ABS pump
9. Ignition circuits
10. Lighting
11. Window lift, central door locking, rear blower
12. Heater, air conditioning
13. Generator