ISO 11992-2:1998
(Main)Road vehicles — Electrical connections between towing and towed vehicles — Interchange of digital information — Part 2: Application layer for braking equipment
Road vehicles — Electrical connections between towing and towed vehicles — Interchange of digital information — Part 2: Application layer for braking equipment
Véhicules routiers — Connexions électriques entre véhicules tracteurs et véhicules tractés — Échange de données numériques — Partie 2: Couche application pour l'équipement de freinage
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 11992-2
First edition
1998-04-01
Road vehicles — Electrical connections
between towing and towed vehicles —
Interchange of digital information —
Part 2:
Application layer for braking equipment
Véhicules routiers — Connexions électriques entre véhicules tracteurs et
véhicules tractés — Échange de données numériques —
Partie 2: Couche application pour l'équipement de freinage
A
Reference number
ISO 11992-2:1998(E)
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ISO 11992-2:1998(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 11992-2 was prepared by Technical Committee ISO/TC 22, Road vehicles,
Subcommittee SC 3, Electrical and electronic equipment.
ISO 11992 consists of the following parts, under the general title Road vehicles — Electrical connections between
towing and towed vehicles — Interchange of digital information:
— Part 1: Physical layer and data link layer
— Part 2: Application layer for braking equipment
— Part 3: Application layer for non-braking equipment
Annex A of this part of ISO 11992 is for information only.
© ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
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Introduction
This part of ISO 11992 is subject to additions which will become necessary to keep pace with experience and
technical advances. Care has been taken to ensure that these additions can be introduced in a compatible way, and
care will have to be taken in the future that such additions remain compatible with previous versions. In particular, it
may become necessary to standardize new parameters and parameter groups. ISO members may request that
such new parameters and parameter groups be included in future editions of ISO 11992 by completing the
"Parameter identification form" in annex A and submitting it to ISO/TC 22/SC 3.
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INTERNATIONAL STANDARD © ISO ISO 11992-2:1998(E)
Road vehicles — Electrical connections between towing and towed
vehicles — Interchange of digital information —
Part 2:
Application layer for braking equipment
1 Scope
This part of ISO 11992 specifies the data content for electronically controlled braking systems to ensure the
interchange of digital information between road vehicles with a maximum authorised total mass greater than
3 500 kg, and their towed vehicles, including communication between towed vehicles.
The objective of the data structure is to optimise the use of the interface, while preserving a sufficient reserve
capacity for future expansion.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part of
ISO 11992. At the time of publication, the editions indicated were valid. All standards are subject to revision, and
parties to agreements based on this part of ISO 11992 are encouraged to investigate the possibility of applying the
most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
ISO 3833:1977, Road vehicles — Types — Terms and definitions.
ISO 11898:1993, Road vehicles — Interchange of digital information — Controller area network (CAN) for high
speed communication.
ISO 11992-1:1998, Road vehicles — Electrical connections between towing and towed vehicles — Interchange of
digital information — Part 1: Physical layer and data link layer.
3 Definitions
For the purpose of this part of ISO 11992, the definitions given in ISO 11992-1 and the following apply.
3.1 commercial vehicle
motor vehicle which, on account of its design and appointments, is used mainly for conveying goods. It may also
tow a trailer [ISO 3833:1977]
3.2 towed vehicle
non-power-driven road vehicle which, on account of its design and appointments, is used to transport persons or
goods and is intended to be towed by a motor vehicle [ISO 3833:1977]
3.3 towing vehicle
power-driven or a non-power-driven vehicle which tows a succeeding vehicle, both being part of a road train
4 General specifications
The data link and the physical layer shall be in accordance with ISO 11992-1.
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To minimise bus loading on the towing/towed vehicle interface, appropriate messages are specified. These
messages may be filtered by a device (node) on each vehicle which shall also provide address assignment and
electrical isolation from the in-vehicle sub-network.
The architecture was chosen to allow any combination of new and old towing and towed vehicles. Multiple towed
vehicles can be connected in any combination; the network shall be capable of addressing any towed vehicle,
including dollies. The truck operator can disconnect and connect towed vehicles at any time and any order and the
network shall adjust and respond accordingly.
5 Application layer
5.1 Message frame format
The application layer provides a string of information that is assimilated into a protocol data unit (PDU). The PDU
provides a framework for organizing the information which will be sent by the CAN data frame.
The 29 bit identifier shall be in accordance with ISO 11898.
The PDU shall consist of seven fields in addition to the specific CAN fields (see figure 1).
The PDU fields are Priority (P), Reserved (R), Data Page (DP), PDU Format (PF), PDU Specific (PS), which can be
a Destination Address (DA) or a Group Extension (GE), Source Address (SA) and data field.
P R DP PF PS SA Data field
Bits 3 1188 8 0 to 64
Figure 1 — 29-bit CAN identifier
5.1.1.1 Priority
The three priority bits are used to optimise message latency for transmission onto the bus only. They should be
globally masked off by the receiver (ignored). The priority of any message may be set from highest, 0 (000 ), to
2
lowest, 7 (111 ). The default for all control oriented messages is 3 (011 ). The default of all other informational
2 2
messages is 6 (110 ).
2
5.1.2 Reserved bit (R)
The reserved bit is reserved for future expansion. This bit should be set to zero for transmitted messages.
5.1.3 Data page (DP)
The data page bit selects an auxiliary page of parameter group descriptions.
5.1.4 PDU format (PF)
The PDU format field is an eight-bit field that determines the PDU format and is one of the fields used to determine
the parameter group number assigned to the data field. Parameter group numbers shall be used to identify or label
a set of commands and data.
5.1.5 PDU specific (PS)
The PDU specific field is an eight-bit field that depends on the PDU format. Depending on the PDU format, it can be
a destination address or a group extension. If the value of the PDU format (PF) field is below 240, then the PDU
specific field is a destination address. If the value of the PF field is 240 to 255, then the PDU specific field contains a
group extension (GE) value (see table 1).
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5.1.5.1 Destination address (DA)
The group extension field contains the specific address of the towing and towed vehicle to which the message is
being sent. Any other device shall ignore this message. The global destination address (255) requires all devices to
listen.
Table 1 — PDU specific field
PDU format PDU specific (PS)
(PF) field field
PDU 1 field 0 to 239 Destination address
PDU 2 field 240 to 255 Group extension
5.1.5.2 Group extension (GE)
The group extension field, in conjunction with the four least significant bits of the PDU format field provide for 4 096
parameter groups per data page.
When the four most significant bits of the PDU format field are set, it indicates that the PS field is a group extension.
5.1.6 Source address (SA)
The source address field is eight-bits long. There shall only be one device on the network with a given source
address. Therefore, the source address field assures that the CAN identifier will be unique, as required by CAN.
5.1.7 Data field
A single CAN data frame provides a maximum of eight data bytes. All eight bytes shall be used, even if fewer than
eight bytes are required for expressing a given parameter group number. This provides a means to easily add
parameters and while remaining compatible with previous revisions which only specified part of the data field.
5.1.8 Parameter group number (PGN)
The parameter group number is a 24-bit number which contains: Reserved bit, Data page bit, PDU Format field
(eight bits), and PDU specific field (eight bits) (see table 2).
If the PF value is less than 240 (F0H; PDU 1 type message), then the lower byte of the PGN is set to zero.
Table 2 — Content of the parameter group number
Byte 1 (MSB)
Byte 2 Byte 3
Bits 8.3 Bit 2 Bit 1
000000b Reserved Data Page PDU format PDU specific
5.1.9 PDU 1 format
The PDU format allows for applicable messages to be sent to either a specific or global destination. PDU 1 format
messages are determined by the PDU format (PF) field. When the PDU format messages field value is 0 to 239, the
message is a PDU 1 format.
5.1.10 PDU 2 format
The PDU 2 format may only be used to communicate global messages. PDU 2 format messages are those where
the PDU format (PF) value is equal to 240 to 255.
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5.2 Address assignment
A road train consists of one commercial vehicle and one or more towed vehicle(s). Dolly axles within the road train
are treated as towed vehicles as well (see figure 2).
Figure 2 — Example of possible road train configuration
The address of the commercial vehicle is fixed.
The respective address of a towed vehicle corresponds to its position within the road train and has to be newly
assigned each time
communication starts,
a towed vehicle has been connected.
For towing vehicle/towed vehicle communication, the addresses shown in table 3 shall be used as source
addresses (SA) and destination addresses (DA). To avoid any transmission conflict during the dynamic address
assignment phase (power-up), the PDU 2 type message shall have even PS (GE) in predecessor transmission
direction and odd PS (GE) in successor transmission direction. If the same message has to be sent in both
transmission directions, two PS (GE) are necessary.
The dynamic address assignment shall be handled by the respective towing vehicle/towed vehicle node and
concerns the determination of the individual position within the road train. The global destination address shall be
only used by the commercial vehicle to broadcast information to all towed vehicles simultaneously.
The dynamic address assignment is based on the transmission of the standard initialization message (see 5.5) by
the respective predecessor within the road train.
Within a road train, the address assignment procedure shall be initiated by the commercial vehicle, using its
standard address for the standard initialization message (see table 3). A powered-up towed vehicle node shall use
the towed vehicle #1 address as the default address to transmit available information, until the standard initialization
has been received and a valid address can be assigned.
Table 3 — Commercial vehicle/towed vehicle addresses
Name Address Predecessor Successor
Commercial vehicle 32d = 20h N/A Towed vehicle position #1
(position #0)
Towed vehicle position #1 200d = C8h Commercial vehicle Towed vehicle position #2
(position #0)
Towed vehicle position #2 192d = C0h Towed vehicle position #1 Towed vehicle position #3
Towed vehicle position #3 184d = B8h Towed vehicle position #2 Towed vehicle position #4
Towed vehicle position #4 176d = B0h Towed vehicle position #3 Towed vehicle position #5
Towed vehicle position #5 168d = A8h Towed vehicle position #4 undefined
Global destination address 255d = FFh undefined undefined
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This allows the towed vehicle node to communicate and to identify its presence to its predecessor immediately after
power-up. This means that several towed vehicles can use the same address, until the address assignment
procedure has been completed.
An assigned address shall be valid as long as the standard initialization message is received from the predecessor
with the corresponding source address and specified message timing.
To provide address assignment for itself and for possible successors, a node shall be capable of permanently
sending the standard initialization message with its own source address (see figure 3)
Permanent sending of the initialization message is necessary to allow immediate towed vehicle address assignment
at any time a towed vehicle might be connected.
In addition, a towed vehicle node shall be capable of
identifying its predecessor by the source address of the standard initialization message;
assigning its own address based on the predecessors address;
identifying potential receiver(s) by the destination address and by the message type.
Towed Towed
Commercial
SA = Com. Vehicle SA = Towed Vehicle #1 SA = Towed Vehicle #2
Vehicle Vehicle
Vehicle
>32d< #1 >200d< #2 >192d<
- sends SA = Commercial Vehicle to successor
- receives SA = Commercial Vehicle from predecessor
- claims SA = Towed Vehicle #1
- sends SA = Towed Vehicle #1 to successor
- receives SA = Towed Vehicle #1 from predecessor
- claims SA = Towed Vehicle #2
- sends SA = Towed Vehicle #2 to successor
Figure 3 — Address assignment
5.3 Message routing
To allow communication between towing and towed vehicles, a node shall be capable of
receiving messages from its predecessor and successor within the road train;
identifying receiver(s) by the destination address (PDU 1 type messages) or the PDU format (PDU 2 type
messages);
routing all messages from its predecessor(s) to its successor(s) within the road train by sending them with the
1)
unchanged source and destination address to its successor within a maximum delay time of = 13 ms;
t
d
routing all messages from its successor(s) to its predecessor(s) within the road train by sending them with the
1)
unchanged source and destination address to its predecessor within a maximum delay time of t = 13 ms.
d
1)
If no provisions are provided for a successor, this function is not required.
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A towed vehicle node shall not route messages to its successor or predecessor within the road train, if the source
address of a message received from its
predecessor corresponds to a road train position higher or equal to its own;
successor corresponds to a road train position lower or equal to its own.
Figures 4 to 9 illustrate the PDU type message sent in different directions.
PF = xxx Towed PF = xxx Towed PF = xxx Towed
Commercial
DA = Towed Vehicle #1 Vehicle DA = Towed Vehicle #2 Vehicle DA = Towed Vehicle #3 Vehicle
Vehicle
SA = Commercial Vehicle #1 SA = Towed Vehicle #1 #2 SA = Towed Vehicle #2 #3
Figure 4 — Example of PDU 1 type messages from towing vehicle to succeeding towed vehicle
PF = xxx Towed PF = xxx Towed Towed
Commercial
DA = Towed Vehicle #2 Vehicle DA = Towed Vehicle #2 Vehicle no transmission Vehicle
Vehicle
SA = Commercial Vehicle #1 SA = Commercial Vehicle #2 #3
Figure 5 — Example of PDU 1 type message from towing vehicle to towed vehicle #2
PF = xxx Towed PF = xxx Towed PF = xxx Towed
Commercial
Vehicle Vehicle Vehicle
DA = GE DA = GE DA = GE
Vehicle
SA = Commercial Vehicle #1 SA = Commercial Vehicle #2 SA = Commercial Vehicle #3
Figure 6 — Example of PDU 2 type message from commercial vehicle to all towed vehicles
PF = xxx Towed PF = xxx Towed PF = xxx Towed
Commercial
DA = Commercial Vehicle Vehicle DA = Towed Vehicle #1 Vehicle DA = Towed Vehicle #2 Vehicle
Vehicle
SA = Towed Vehicle #1 #1 SA = Towed Vehicle #2 #2 SA = Towed Vehicle #3 #3
Figure 7 — Example of PDU 1 type messages from towed vehicle to preceding towing vehicle
PF = xxx Towed PF = xxx Towed PF = xxx Towed
Commercial
DA = Commercial Vehicle Vehicle DA = Commercial Vehicle Vehicle DA = Commercial Vehicle Vehicle
Vehicle
SA = Towed Vehicle #3 #1 SA = Towed Vehicle #3 #2 SA = Towed Vehicle #3 #3
Figure 8 — Example of PDU 1 type message from towed #3 to commercial vehicle
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PF = xxx Towed PF = xxx Towed PF = xxx Towed
Commercial
DA = GE Vehicle DA = GE Vehicle DA = GE Vehicle
Vehicle
SA = Towed Vehicle #2 #1 SA = Towed Vehicle #2 #2 SA = Towed Vehicle #2 #3
Figure 9 — Example of PDU 2 type message from towed vehicle #2
5.4 Parameters
5.4.1 Parameter ranges
Table 4 specifies the ranges used to determine the validity of transmitted signal.
Table 5 specifies the ranges used to denote the state of a discrete parameter and table 6 defines the ranges used
to denote the state of a control mode command.
The values in the range "error indicator" provide a means for a module to immediately indicate that valid parameter
data is not currently available due to some type of error in the sensor, sub-system, or module. Additional information
about the failure may be available using diagnostic requests.
The values in the range "not available" provide a means for a module to transmit a message which contains a
parameter that is not available or not supported in that module. This value does not replace the "error indication".
The values in the range "not requested" provide a means for a device to transmit a command message and identify
those parameters where no response is expected from the receiving device.
After power on, a node should internally set the "availability bits" of received parameters as not available and
operate with default values until valid data is received. When transmitting, undefined bytes should be sent as
255Dec (FFHex) and undefined bits should be sent as "1".
If a component failure prevents the transmission of valid data for a parameter, the error indicator, as described in
tables 4 and 5, shall be used in place of that parameter data. However, if the measured or calculated data has
yielded a value that is valid yet exceeds the defined parameter range, the error indicator shall not be used. The data
should be transmitted using the appropriate minimum or maximum parameter value.
A word (16 bit) parameter shall be sent, least significant byte first, most significant byte second.
Table 4 — Transmitted signal ranges
Value range
Parameter Unit
1 byte 2 bytes
Dec 0 to 250 0 to 64255
Signal range
Hex 00 to FA 0000 to FAFF
Dec 251 to 253 64256 to 65023
Reserved range for
future indicator bits
Hex FB to FD FB00 to FDFF
Dec 254 65024 to 65279
Error indicator
Hex FE FExx
Dec 255 65280 to 65535
Not available or
not requested
Hex FF FFxx
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Table 5 — Transmitted values for discrete parameters
Range name Transmitted value
Disabled (off, passive, insufficient) 00
Enabled (on, active, sufficient) 01
Error indicator 10
Not available or not installed 11
Table 6 — Transmitted values for control requests
Range name Transmitted value
Request to disable function (turn off, etc.) 00
Request to enable function (turn on, etc.) 01
Reserved 10
Don't care/take no action 11
(leave function as it is)
5.4.2 Parameter specifications
5.4.2.1 General
A description of each parameter is given in 5.4.2.2 to 5.4.2.32. The description includes data length, data type,
resolution and range for reference.
The type of data shall also be identified for each parameter. Data may be either status or measured. Status
specifies the present state of a multi-state parameter or function as a result of action taken by the transmitting node.
Note that specific confirmation of this action is not necessarily assured. For instance, the status can indicate that a
solenoid has been activated, even if no measurement has been taken to ensure the solenoid accomplished its
function. An example of measured-type data is "vehicle service brake active/passive".
Measured data conveys the current value of a parameter as measured or observed by the transmitting node to
determine the condition of the defined parameter. An example of status-type data is "service brake demand value".
Negative signed torque parameter indicates deceleration, positive signed torque indicates acceleration in
accordance to the drive line of the vehicle.
5.4.2.2 Park brake demand value
The requested brake pressure value of the parking brake as a percentage of maximum.
Data length: 1 byte
Resolution: 0,4 %/bit gain, 0 % offset
Data range: 0 % to 100 %
Type: Status
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5.4.2.3 Retarder demand value
The demanded value of the retarder on the towed vehicle(s) as a percentage of the absolute peak torque of
retarder.
Data length: 1 byte
Resolution: 1 %/bit gain, – 125 % offset
Data range: – 125 % to 125 %
Operating range: – 125 % to 0 %
Type: Status
NOTE — Retarder demand torque is defined in indicated torque as a percentage of peak retarder torque.
In the definition of power train speed/torque the retarder torque reaction is a deceleration defined by a negative
signed parameter.
EXAMPLE
Retarder demand value = 75 % × absolute Peak Torque of retarder
Calculation:
1st step Data Content (DC) of RDV:
RDV − Offset−−75%%()−125
DC = = = 50
Resolution 1%/bit
2nd step Measured (Actual) Retarder Torque (ART)
ART − Offset
DC = = 50
Resolution
ART = DC × Resolution + Offset
ART = 50 × 1% + (– 125%)
ART = – 75 %
5.4.2.4 Service brake demand value
The requested brake pressure value of the service brake demanded by the driver.
Data length: 2 bytes
Resolution: 5/256 kPa/bit gain, 0 kPa offset
Data range: 0 kPa to 1255 kPa
Type: Status
NOTES
1 This value may be modified by the coupling force control function, which has been specified by ECE Regulation R.13.
5
2 1 bar = 10 Pa.
5.4.2.5 Wheel-based (from braking system) vehicle speed
Actual speed of the vehicle (positive value for forward and backward speed) calculated as the average of the wheel
speeds of one axle influenced by slip and filtered by a frequency range of 5 Hz to 20 Hz.
Data length: 2 bytes
Resolution: 1/256 kmph/bit gain, 0 kmph offset
Data range: 0 kmph to 250 kmph
Type: Measured
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5.4.2.6 Reference retarder torque
This parameter is the 100 % reference value for all defined indicated retarder torque parameters. It is only defined
once and does not change if a different retarder torque map becomes valid.
Data length: 2 bytes,
Resolution: 1 Nm/bit gain, 0 Nm offset,
Data range: 0 Nm to 6 4255 Nm.
Type: Measured
5.4.2.7 Actual percentage of retarder peak torque
Actual torque of the retarder as negative percentage of maximum.
Data length: 1 byte
Resolution: 1 %/bit gain, – 125 % offset
Data range: – 125 % to +125 %
Operating range: – 125 % to 0 %
Type: Measured
5.4.2.8 Axle load sum
Sum of the static vertical loads of the vehicles axles.
Data length: 2 bytes
Resolution: 2 kg/bit gain, 0 kg offset
Data range: 0 kg to 128 510 kg
Type: Measured
5.4.2.9 Pneumatic supply pressure
Actual supply pressure of the reservoir of the braking system.
Data length: 1 byte
Resolution: 5 kPa/bit gain, 0 kPa offset
Data range: 0 kPa to 1 250 kPa (12,5 bar)
Type: Measured
5.4.2.10 Tyre identification
Identification number of the tyre with
insufficient pressure, or
brake linings, or
specific brake temperature.
The identification number specifies the wheel position on each axle (bit 1 to 4) and the number of axles starting from
the front vehicle (bit 5 to 8) (see figure 10).
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The identification number is in conjunction with the status information in the message.
Data length: 1 byte
Resolution: 1/bit gain, 0 offset
Data range: 1 - 15 wheel position (low bits)
1 - 15 axle position (high bits)
Type: Measured
The tyre identification is labelled sequentially from the vehicle symmetric line, starting from '9' incrementing on the
right side, and from '7' decrementing on the left side. '8' is used for one wheel on the symmetric line.
Figure 10 — Wheel and axle position
5.4.2.11 Brake lining
Actual relative value of brake lining of a specific brake.
Data length: 1 byte
Resolution: 0,4 %/bit gain, 0 % offset
Data range: 0 % to 100 %
Type: Measured
5.4.2.12 Brake temperature
Actual brake temperature.
Data length: 1 byte
Resolution: 10 °C/bit gain, 0 % offset
Data range: 0 °C to 2 500 °C
Type: Measured
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5.4.2.13 Tyre pressure
Actual tyre pressure without corrections.
Data length: 1 byte
Resolution: 10 kPa/bit gain, 0 kPa offset
Data range 0 kPa to 2 500 kPa
Type: Measured
5.4.2.14 Vehicle retarder control active/passive
This signal indicates the active/passive state in all cases when the installed retarder is applied by the drivers
demand or by other systems (brakes).
NOTE — "Applied" means that the retarder starts to increase its torque and decelerates the vehicle.
00 — Retarder 'passive'
01 — Retarder 'active'
Type: Measured
5.4.2.15 Vehicle service brake active/passive
Signal indicating the service brake of the towed vehicle is active/passive, by supervising the brake pressure.
00 — Vehicle service brake passive
01 — Vehicle service brake active
Type: Measured
5.4.2.16 Automatic towed vehicle braking active/passive
Signal indicating the automatic towed vehicle braking is active/passive. This function will occur when the pneumatic
supply is insufficient or not connected.
00 — Vehicle automatic braking passive
01 — Vehicle automatic braking active
Type: Measured
5.4.2.17 Vehicle ABS active/passive
Signal indicating the ABS is active/passive. The signal is set active when the ABS starts to modulate the wheel
brake pressure, and is reset to passive when all wheels are in stable condition for a certain time period. The signal
can also be set to active when driven wheels are in high slip (e.g. caused by retarder).
NOTE — Active does not mean "installed" or "enabled", but indicates an actual ABS situation. In case of at least one wheel
speed error, the error indicator shall have priority (see table 5).
00 — Vehicle ABS passive, but installed
01 — Vehicle ABS active
Type: Measured
5.4.2.18 Vehicle electrical supply sufficient/insufficient
Signal indicating the actual supply voltage is sufficient/insufficient for proper brake function (including over voltage).
00 — Vehicle electrical supply insufficient
01 — Vehicle electrical supply sufficient
Type: Status
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5.4.2.19 Vehicle pneumatic supply sufficient/insufficient
Signal indicating the actual supply pressure of the reservoir of the braking system is insufficient or sufficient.
00 — Vehicle pneumatic supply insufficient
01 — Vehicle pneumatic supply sufficient.
Type: Status
5.4.2.20 Spring brake installed
Signal indicating the vehicle has one or more axle(s) fitted with spring brakes.
00 — Vehicle without spring brakes
01 — Vehicle with spring brakes
Type: Status
5.4.2.21 Electrical load proportional function
Signal indicating the vehicle is equipped with an electrical load proportional function.
00 — Vehicle without electrical load proportional function
01 — Vehicle with electrical load proportional function
Type: Status
5.4.2.22 ABS off-road request
Request to activate the ABS off-road function. The switch signal is independent of an actual ABS control situation.
00 — ABS off road switch off
01 — ABS off road switch on
Type: Status
5.4.2.23 ASR brake control active/passive
Signal which indicates that ASR brake control is active/passive. Active means that ASR actually controls wheel
brake pressure at one or more wheels of the driven axle(s).
NOTE — Active does not mean "installed" or "enabled", but indicates an actual ASR situation.
00 — ASR brake control passive, but installed
01 — ASR brake control active
Type: Measured
5.4.2.24 ASR engine control active/passive
Signal which indicates that ASR engine control is active/passive. Active means that ASR actually tries to control the
engine. This status is independent of other control commands to the engine (e.g. from the transmission) which may
have higher priority.
NOTE — Active does not mean "installed" or "enabled", but indicates an actual ASR situation.
00 — ASR engine control passive
01 — ASR engine control active
Type: Measured
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5.4.2.25 Pneumatic co
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