Mercedes Benz Actros Wiring Diagrams
EBS
Electronically controlled
Brake system
in motor coaches
System and function a l
description
1. Edition
© Copyright WABCO 2003
Vehicle Control Systems
An American Standard Company
8150004083
The right of amendment is reserved
Version 001/07.01
EBS
1. Introduction / Advantages of EBS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
2. System structure in buses
System structure 2-axle bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
WABCO EBS construction kit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
System variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Wiring diagram 2-axle bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Wiring diagram 3-axle bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3. Description of components
Brake signal transmitter 480 00. ... 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
EBS central module 446 135 ... 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Proportional relay valve 480 202 ... 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3/2 relay valve 480 205 ... 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Axle modulator 480 103 ... 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
4. Description of EBS function
Table of Contents
Page
Function of the electro-pneumatic unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Function of pneumatic redundancy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Additional redundancy on the front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Rear axle redundancy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Electrical / electronic structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Control functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Backup functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Halt brake, brake hold and release aid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
5. Error recognition and display
Error recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Error display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6. EBS ”emergency modes” / EBS test types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
7. WABCO PC - Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Diagnostic equipment for WABCO EBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Diagnostic Software EBS Euro. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
8. Parameter Setting
Parameter setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
2
Introduction / Advantages of EBS
EBS
1.
Introduction
The demands m ade on brakin g sy stems a re i ncre asing
steadily. Therefore, the development and introduction of
an electronic braking system (EBS) is a logical step.
EBS increases tr affic safety through reduced stoppi ng
distance and improved brake stability. The full diagnosis
and surveillance functions as well as the display of brake
lining wear offer an effective fleet logistics.
Advantages of EBS
EBS reduces service costs considerably.
q The electronic braking system has a lot of
functions. The aim is to maximise braking safety at
reduced costs, for instance by optimising wheel
brake lining wear.
q Setting pressure, according to wear criteria, to the
front and rear a xle results in uniform lining wear.
Overall wear is minimised by making the load on all
wheel brakes uniform. Moreover, servicing and
lining replacement are done at the same time. This
reduces down-time costs.
Increased brake safety
WABCO did not only take existing regulations into
consideration while developing EBS. Top priority was
given to safety and user advantages. This is why a
vehicle with EBS can clearly do more than is required by
law.
The high safety quality attributed to EBS is due to
several factors:
q Braking time is red uced through s horter respons e
time and pressure build-u p time of the brakes on
the front and rear axle(s).
q The improved ABS function increases vehicle
stability when brakes are activated.
q The components of the fr ont and rear ax le brak in g
system and brake lining wear are monitored
permanently.
q The integrated ASR function also provides
optimum vehicle s tability and traction during start
and acceleration.
q Depending on the vehicle utilisation profile and
other factors, this also means considerable savings
for the vehicle user. In terms of wheel brake service
costs alone, a firsthand owner will save more
money with an electr onically braked bus than with
a vehicle with a conventional braking system.
3
2.
EBS
System structure in buses
EBS braking system for buses with no attachment (4S/4M system )
9
1
7
4
10
11
2
6
3
5
12
13
8
14
Legend:
EBS components:
1 EBS central module
2 Brake signal transm itt er
3 Proportional relay valve
4 ABS solenoid valv e
5 Axle modulator
6 3/2 relay valve
7 ABS sensors
Other components:
8 Compressor
9 Air dryer
10 Four-circuit protection valve
11 Air reservoir
12 Ha nd br ake valv e
13 Relay valve FBA
14 Brake cylinder
4
System structure in buses
WABCO EBS construction kit
EBS
2.
The design and structure of WABCO EBS allow high
flexibility for vehicle manufacturers during system
construction.
In terms of range
q subsystem or full system
q addition and cut-off redundancy
supply
q electrical interfaces
the most complex demand s can, therefore, be met. To
meet the vital needs of the vehicle owner, WABCO
recommends an EBS with an individual pressure control
unit on the front and r ear axle, and which provides for
pneumatic redundancies in all brake circuits.
third axle
Battery
2P/1E-EBS
AME = Axle modulator
BWG = Brake signal transmitter
ECAS = Electronically Air Suspension System
EMR = Electronically engine control
PRV = Proportional relay valve
REDV = 3/2 relay valve (redundancy valve)
RET = Retarder
RV = Relay valve
S = Speed sensor
V = Wear indicator
The EBS described here consists of a dual-circuit, purely
pneumatic unit and a superimposed single-circuit,
electro-pneumatic unit. This configuration is described
as 2P/1E system.
The single-circuit, electro-pneumatic unit comprises a
central electronic control device (central module), the
axle modulator with integrated electronic unit for the rear
axle, and, if necessary, the axle modulator for the th ird
axle, a brake signal transmitter with two integrated
halt brake
desired value sensors and brake switches, as w ell as a
proportional relay valve and two ABS valves for the front
axle.
In terms of structure, the dual-circuit pneumatic unit
basically corres ponds to that of a conventional brak ing
system. This unit serves as redundancy and only
becomes active in case of electro-pneumatic circuit
failure.
5
2.
EBS
System structure in buses
EBS 4S/4M in buses with optional trailer control
Niveau-
3
Level control
regelung
air reservoir
8
7
4
ISO 11992
Luftbehälter
9
Motor
Engine
Fahrzeugdatenbus SAE J 1939
vehicle data bus SAE J 1939
WABCO
446 130 XXX 0
EPB 4S/4M
WABCO
2
WABCO
IIII II IIII III
Retarder
Retarder
Getriebe
Gearbox
1
O
C
B
A
W
ISO 7638
6
WAB CO
WABCO
WABCO
1 Zentralsteuergerät EBS
2 Bremswertgeber
1 Central control unit EBS
3 Prop. Relaisventil
2 Brake signal transmitter
4 ABS Magnetregelventil
3 Proportional Relay valve
5 Achsmodulator
4 ABS Solenoid Control valve
6 Anhängersteuerventil
5 Axle modulator
7 Splus Stabsensoren
6 Trailer control valve
8 Verschleißsensoren
9 Redundanzventil
8
7
rod sensor
7 S
plus
8 Wear indicators
9 3/2 relay valve (redundancy valve
)
5
EBS 6S/6M in articulated buses
Engine Gearbox
Motor
Fahrzeugdatenbus SAE J 1939
vehicle data bus SAE J 1939
2
WABCO
WABCO
446 130 XXX 0
EPB 4S/4M
IIII II IIII III
WABCO
Retarder
Retarder
1
O
W
Getriebe
C
B
3
A
4
4
7
8
Anhänger-
trailer control
steuerventil
valve
Niveau-
Level control
regelung
8
7
Optional
7
8
1 Central control unit EBS
2 Brake signal transmitter
3 Proportional Relay valve
4 ABS Solenoid Control valve
5 Axle modulator
6 3/2 relay valve (redundancy valve
7 S
plus
8 Wear indicators
9 Relay valve
WABCO
9
WABCO
WABCO
5
1 Zentralsteuergerät EBS
2 Bremswertgeber
3 Prop. Relaisventil
4 ABS Magnetregelventil
5 Achsmodulator
Redundancy valve
6 redundanzventil
rod sensor
7 Splus Stabsensoren
8 Verschleißsensoren
9 Relaisventil
8
7
WABCO
6
)
8
7
WABCO
5
WABCO
4
7
8
7
8
7
8
6
System structure in buses
Wiring diagram 841 801 701 0: Dual-axle bus (4S/4M)
EBS
2.
7
2.
EBS
System structure in buses
Wiring diagram 841 801 702 0: Three-axle bus (6S/6M)
8
Description of components
Brake signal transmitter 480 001/ 002 ... 0
The brake signal transmitter is used to produce electrical
and pneumatic sign als, and to increase and decr ease
the air pressure of th e electronically con trolled braking
system. The device has a dual-c ircuit pneumatic and a
dual-circuit electrical structure. Actuation start is recorded electronically by a double s witch. T he operati ng tappet’s route is controlle d and transmitted as pulse-width
modulated electrical signal. Further pneumatic redundancy pressure is delivered in circuits 1 and 2. The
pressure in the seco nd circuit is retained slight ly in the
process. In case of (electrical or pneumatic) failure of a
circuit, the other circuits remain functional.
Depending on bus type , the brake signal transmitter is
actuated via a running pl ate (480 002 ... 0) 0) or via a
push pedal using the tappet (480 001 ... 0).
EBS
3.
How it works:
9
3.
EBS
Description of components
EBS central module 446 135 ... 0
The central module is used to control and monitor the
electronically controlled braking system. It determines
the vehicle’s nominal delay from the signals received by
the brake signal tr ansm itter. The nominal del ay and the
wheel velocity measured by the speed sensors are input
signal for the electro-pneumatic control unit, which uses
it to calculate nomina l pres sur e v alu es for the fr o nt axle
and rear axle(s). The front axle’s nominal pressure value
is then compared with the measured actual val ue, and
any existing deviations corrected with the help of the
proportional relay valve. Moreover, the wheel velocity is
evaluated so that in case of locking, an ABS control can
be carried out by modulating the braking pressure in the
brake cylinders. The central module exchanges EBS
system bus related data with the axle modulators.
The central module communicates with other systems
(engine control un it, retarder, display unit, etc.) via the
vehicle data bus in accordance with SAE J 1939.
KOM-integrated central unit:
10
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