Page 594 of 873

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.
Page 601 of 873

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
Page 821 of 873

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)
Page 822 of 873
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