ISO 11992-2:2023

Road vehicles — Interchange of digital information on electrical connections between towing and towed vehicles — Part 2: Application layer for brakes and running gear

This document specifies the SAE J1939-based application layer, the payload of messages, and parameter groups for electronically controlled braking systems, including anti-lock braking systems (ABS), vehicle dynamics control systems (VDC), and running gears equipment, to ensure the interchange of digital information between road vehicles with a maximum authorized total mass greater than 3 500 kg and their towed vehicles, including communication between towed vehicles. Conformance and interoperability test plans are not part of this document.

Véhicules routiers — Échange d'informations numériques sur les connexions électriques entre véhicules tracteurs et véhicules tractés — Partie 2: Couche d'application pour les équipements de freinage et les organes de roulement

General Information

• Status: Published
• Publication Date: 09-Mar-2023
• ICS: 43.040.15 - Car informatics. On board computer systems
• Technical Committee: ISO/TC 22/SC 31 - Data communication
• Drafting Committee: ISO/TC 22/SC 31/WG 4 - Network applications
• Current Stage: 6060 - International Standard published
• Start Date: 10-Mar-2023
• Due Date: 02-Jul-2023
• Completion Date: 10-Mar-2023

Relations

• Revises: ISO 11992-2:2014 - Road vehicles — Interchange of digital information on electrical connections between towing and towed vehicles — Part 2: Application layer for brakes and running gear
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11992-2
Fourth edition
2023-03
Road vehicles — Interchange of digital
information on electrical connections
between towing and towed vehicles —
Part 2:
Application layer for brakes and
running gear
Véhicules routiers — Échange d'informations numériques sur
les connexions électriques entre véhicules tracteurs et véhicules
tractés —
Partie 2: Couche d'application pour les équipements de freinage et les
organes de roulement
Reference number
ISO 11992-2:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO 11992-2:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 11992-2:2023(E)
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.4
4.1 Symbols . 4
4.2 Abbreviated terms . 4
5 Conventions . 5
6 APP – Parameter specification . 5
6.1 General definitions. 5
6.2 APP – Identification parameter specification . 6
6.2.1 APP – Axle/wheel identification . 6
6.2.2 APP – Identification data index . 8
6.2.3 APP – Identification data indexed content . 9
6.3 APP – Braking systems parameter specification . 10
6.3.1 APP – Park brake demand relative pressure . 10
6.3.2 APP – Service brake demand pressure . 10
6.3.3 APP – Vehicle service brake status . 11
6.3.4 APP – Braking system wheel-based vehicle speed . 11
6.3.5 APP – Vehicle retarder control status . 11
6.3.6 APP – Retarder demand relative torque .12
6.3.7 APP – Retarder wheel torque reference .13
6.3.8 APP – Retarder relative peak torque . 14
6.3.9 APP – Retarder actual maximum positive torque . 14
6.3.10 APP – Retarder actual maximum negative torque . 14
6.3.11 APP – Axle load sum .15
6.3.12 APP – Pneumatic supply pressure . 15
6.3.13 APP – Brake lining . 15
6.3.14 APP – Brake temperature . 16
6.3.15 APP – Tyre pressure . 16
6.3.16 APP – Automatic towed vehicle braking status . 16
6.3.17 APP – Vehicle ABS status . 17
6.3.18 APP – Vehicle electrical supply status . 17
6.3.19 APP – Vehicle pneumatic supply status . 18
6.3.20 APP – Spring brake installation status . 18
6.3.21 APP – Electrical load proportional function installation status . 18
6.3.22 APP – Load proportional function installation status . 19
6.3.23 APP – ABS off-road request . 19
6.3.24 APP – ASR brake control status . 19
6.3.25 APP – ASR engine control status . 20
6.3.26 APP – Pneumatic control line status . 20
6.3.27 APP – Two electrical circuits brake demand status .20
6.3.28 APP – Tyre pressure status . 21
6.3.29 APP – Brake lining status . 21
6.3.30 APP – Brake temperature status . 22
6.3.31 APP – Brake light switch . 22
6.3.32 APP – Vehicle type . 22
6.3.33 APP – Red warning signal request . 23
6.3.34 APP – Amber warning signal request . 23
6.3.35 APP – Electrical supply of non-braking systems status .23
6.3.36 APP – Loading ramp approach assistance status . . 24
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO 11992-2:2023(E)
6.3.37 APP – VDC active . 24
6.3.38 APP – Road curvature . 25
6.3.39 APP – Wheel speed difference main axle . 25
6.3.40 APP – Supply line braking . 25
6.3.41 APP – Spring brake status . 26
6.3.42 APP – Relative brake demand for front or left vehicle side .26
6.3.43 APP – Relative brake demand for rear or right vehicle side . 27
6.3.44 APP – Support of side- or axle-wise brake force distribution . 27
6.3.45 APP – Lateral acceleration . 27
6.3.46 APP – Stop lamps request .28
6.3.47 APP – Braking via electric control line support .28
6.3.48 APP – Geometric data index .28
6.3.49 APP – Geometric data indexed content .29
6.3.50 APP – Brake cylinder pressure first axle, left wheel . 32
6.3.51 APP – Brake cylinder pressure first axle, right wheel . 33
6.3.52 APP – Brake cylinder pressure second axle, left wheel .33
6.3.53 APP – Brake cylinder pressure second axle, right wheel .33
6.3.54 APP – Brake cylinder pressure third axle, left wheel .34
6.3.55 APP – Brake cylinder pressure third axle, right wheel .34
6.3.56 APP – Wheel speed first axle, left wheel . 35
6.3.57 APP – Wheel speed first axle, right wheel . 35
6.3.58 APP – ROP system status . 35
6.3.59 APP – YC system status. 36
6.3.60 APP – Towed vehicle ROP system request .36
6.3.61 APP – Towed vehicle YC system request .36
6.3.62 APP – Vehicle combination ABS status . 37
6.3.63 APP – Towed vehicle detection status . 37
6.3.64 APP – Reverse gear status . .38
6.3.65 APP – External brake request status .38
6.3.66 APP – Emergency braking status .38
6.4 APP – Running gear equipment parameter specification .39
6.4.1 APP – Driven axle load . 39
6.4.2 APP – Nominal vehicle body level, front axle .39
6.4.3 APP – Nominal vehicle body level, rear axle .40
6.4.4 APP – Relative vehicle body level, front axle .40
6.4.5 APP – Relative vehicle body level, rear axle .40
6.4.6 APP – Level control request . 41
6.4.7 APP – Level control status . 41
6.4.8 APP – Level change request, front axle . 41
6.4.9 APP – Level change request, rear axle . 42
6.4.10 APP – Level change status, front axle . 42
6.4.11 APP – Level change status, rear axle . 42
6.4.12 APP – Lift axle 1 position request . 43
6.4.13 APP – Lift axle 2 position request . 43
6.4.14 APP – Lift axle 3 position request .44
6.4.15 APP – Lift axle 4 position request .44
6.4.16 APP – Lift axle 5 position request .44
6.4.17 APP – Lift axle 1 position . 45
6.4.18 APP – Lift axle 2 position . 45
6.4.19 APP – Lift axle 3 position . 45
6.4.20 APP – Lift axle 4 position .46
6.4.21 APP – Lift axle 5 position .46
6.4.22 APP – Steering axle locking request .46
6.4.23 APP – Steering axle locking status . 47
6.4.24 APP – Traction help (load transfer) request . 47
6.4.25 APP – Traction help (load transfer) status .48
6.4.26 APP – Ride height request .48
6.4.27 APP – Ride height level .48
iv
  © ISO 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 11992-2:2023(E)
6.4.28 APP – Normal level .49
6.4.29 APP – Ramp level request .49
6.4.30 APP – Ramp level .49
6.4.31 APP – Ramp level position .50
6.4.32 APP – Ramp level storage request .50
6.4.33 APP – Ramp level storage status .50
6.4.34 APP – Stop level change request . 51
6.4.35 APP – Stop level change request acknowledge . 51
6.4.36 APP – Parking and towed vehicle air pressure . 51
6.4.37 APP – Auxiliary equipment supply pressure . 52
6.4.38 APP – Tyre pressure threshold detection . 52
6.4.39 APP – Air leakage detection . 53
6.4.40 APP – Tyre temperature . 53
6.4.41 APP – Tyre module power supply status .54
6.5 APP – Axle load parameter specification .54
6.5.1 APP – Axle load .54
6.5.2 APP – Axle load calibration data storage request .54
6.5.3 APP – Axle load calibration data storage status . 55
6.5.4 APP – Axle load measured by external scale. 55
6.5.5 APP – Axle load measured by towed vehicle .56
6.5.6 APP – Axle load calibration data load level .56
6.5.7 APP – Axle load calibration type . 57
6.5.8 APP – Maximum driven axle load . 57
6.6 Ride height parameter specification .58
6.6.1 APP – Extended ride height and ramp level storage .58
6.6.2 APP – Ride height and ramp level set request .58
6.6.3 APP – Ride height storage request .58
6.6.4 APP – Ride height storage . 59
6.6.5 APP – Neutral gear request . 59
6.6.6 APP – Rear obstacle distance . 59
6.6.7 APP – Immobilizer status .60
6.6.8 APP – Fifth wheel load .60
6.6.9 APP – Ambient air temperature . 61
6.6.10 APP – Parking brake status . 61
6.6.11 APP – Neutral gear status. 61
6.7 APP – Software update parameter specification . 61
6.7.1 APP – Vehicle software update request . 61
6.7.2 APP – Vehicle software update request acknowledgement . 62
7 APP – PG specification .62
7.1 APP – Overview of PGs . 62
7.2 APP – Message transmission in case of multiple towed vehicles .64
7.3 APP – Towing vehicle .64
7.3.1 APP – General specification .64
7.3.2 APP – General PGs, transmitted from the towing to the towed vehicle .65
7.3.3 APP – Electronic brake system PGs, transmitted from the towing to the
towed vehicle .65
7.3.4 APP – Running gear equipment PGs, transmitted from the towing to the
towed vehicle . 67
7.4 APP – Towed vehicle . 70
7.4.1 APP – General PGs, transmitted from the towed to the towing vehicle . 70
7.4.2 APP – Electronic brake system PGs, transmitted from the towed to the
towing vehicle . 70
7.4.3 APP – Running gear equipment PGs, transmitted from towed to towing
vehicle . 75
8 APP – Address assignment .78
8.1 APP – General requirements . 78
8.2 APP – Road train configuration . 79
v
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO 11992-2:2023(E)
8.3 APP – Address assignment method of a towing and towed vehicle .79
8.4 APP – Vehicle node capabilities .80
9 SI – Service interface definition between application and OSI layers .82
9.1 SI – A_Data.req, A_Data.ind, and A_Data.con service interface .82
9.2 SI – A_Data.req, A_Data.ind, and A_Data.con service interface parameter mapping .82
9.3 SIP – Service interface data type definitions .83
10 AL – Application layer .83
10.1 AL – Message PDU format .83
10.2 AL – A_PDU specification .83
11 PL – Presentation layer .83
Annex A (normative) Geometric dimensions .
...

INTERNATIONAL ISO
STANDARD 11992-2
Fourth edition
Road vehicles — Interchange of digital
information on electrical connections
between towing and towed vehicles —
Part 2:
Application layer for brakes and
running gear
Véhicules routiers — Échange d'informations numériques sur
les connexions électriques entre véhicules tracteurs et véhicules
tractés —
Partie 2: Couche d'application pour les équipements de freinage et les
organes de roulement
PROOF/ÉPREUVE
Reference number
ISO 11992-2:2022(E)
© ISO 2022

---------------------- Page: 1 ----------------------
ISO 11992-2:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
PROOF/ÉPREUVE © ISO 2022 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 11992-2:2022(E)
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.4
4.1 Symbols . 4
4.2 Abbreviated terms . 4
5 Conventions . 5
6 APP – Parameter specification . 5
6.1 General definitions. 5
6.2 APP – Identification parameter specification . 6
6.2.1 APP – Axle/wheel identification . 6
6.2.2 APP – Identification data index . 8
6.2.3 APP – Identification data indexed content . 9
6.3 APP – Braking systems parameter specification . 10
6.3.1 APP – Park brake demand relative pressure . 10
6.3.2 APP – Service brake demand pressure . 10
6.3.3 APP – Vehicle service brake status . 11
6.3.4 APP – Braking system wheel-based vehicle speed . 11
6.3.5 APP – Vehicle retarder control status . 11
6.3.6 APP – Retarder demand relative torque .12
6.3.7 APP – Retarder wheel torque reference .13
6.3.8 APP – Retarder relative peak torque . 14
6.3.9 APP – Retarder actual maximum positive torque . 14
6.3.10 APP – Retarder actual maximum negative torque . 14
6.3.11 APP – Axle load sum .15
6.3.12 APP – Pneumatic supply pressure . 15
6.3.13 APP – Brake lining . 15
6.3.14 APP – Brake temperature . 16
6.3.15 APP – Tyre pressure . 16
6.3.16 APP – Automatic towed vehicle braking status . 16
6.3.17 APP – Vehicle ABS status . 17
6.3.18 APP – Vehicle electrical supply status . 17
6.3.19 APP – Vehicle pneumatic supply status . 18
6.3.20 APP – Spring brake installation status . 18
6.3.21 APP – Electrical load proportional function installation status . 18
6.3.22 APP – Load proportional function installation status . 19
6.3.23 APP – ABS off-road request . 19
6.3.24 APP – ASR brake control status . 19
6.3.25 APP – ASR engine control status . 20
6.3.26 APP – Pneumatic control line status . 20
6.3.27 APP – Two electrical circuits brake demand status .20
6.3.28 APP – Tyre pressure status . 21
6.3.29 APP – Brake lining status . 21
6.3.30 APP – Brake temperature status . 22
6.3.31 APP – Brake light switch . 22
6.3.32 APP – Vehicle type . 22
6.3.33 APP – Red warning signal request . 23
6.3.34 APP – Amber warning signal request . 23
6.3.35 APP – Electrical supply of non-braking systems status .23
6.3.36 APP – Loading ramp approach assistance status . . 24
iii
© ISO 2022 – All rights reserved PROOF/ÉPREUVE

---------------------- Page: 3 ----------------------
ISO 11992-2:2022(E)
6.3.37 APP – VDC active . 24
6.3.38 APP – Road curvature . 25
6.3.39 APP – Wheel speed difference main axle . 25
6.3.40 APP – Supply line braking . 25
6.3.41 APP – Spring brake status . 26
6.3.42 APP – Relative brake demand for front or left vehicle side .26
6.3.43 APP – Relative brake demand for rear or right vehicle side . 27
6.3.44 APP – Support of side- or axle-wise brake force distribution . 27
6.3.45 APP – Lateral acceleration . 27
6.3.46 APP – Stop lamps request .28
6.3.47 APP – Braking via electric control line support .28
6.3.48 APP – Geometric data index .28
6.3.49 APP – Geometric data indexed content .29
6.3.50 APP – Brake cylinder pressure first axle, left wheel . 32
6.3.51 APP – Brake cylinder pressure first axle, right wheel . 33
6.3.52 APP – Brake cylinder pressure second axle, left wheel .33
6.3.53 APP – Brake cylinder pressure second axle, right wheel .33
6.3.54 APP – Brake cylinder pressure third axle, left wheel .34
6.3.55 APP – Brake cylinder pressure third axle, right wheel .34
6.3.56 APP – Wheel speed first axle, left wheel . 35
6.3.57 APP – Wheel speed first axle, right wheel . 35
6.3.58 APP – ROP system status . 35
6.3.59 APP – YC system status. 36
6.3.60 APP – Towed vehicle ROP system request .36
6.3.61 APP – Towed vehicle YC system request .36
6.3.62 APP – Vehicle combination ABS status . 37
6.3.63 APP – Towed vehicle detection status . 37
6.3.64 APP – Reverse gear status . .38
6.3.65 APP – External brake request status .38
6.3.66 APP – Emergency braking status .38
6.4 APP – Running gear equipment parameter specification .39
6.4.1 APP – Driven axle load . 39
6.4.2 APP – Nominal vehicle body level, front axle .39
6.4.3 APP – Nominal vehicle body level, rear axle .40
6.4.4 APP – Relative vehicle body level, front axle .40
6.4.5 APP – Relative vehicle body level, rear axle .40
6.4.6 APP – Level control request . 41
6.4.7 APP – Level control status . 41
6.4.8 APP – Level change request, front axle . 41
6.4.9 APP – Level change request, rear axle . 42
6.4.10 APP – Level change status, front axle . 42
6.4.11 APP – Level change status, rear axle . 42
6.4.12 APP – Lift axle 1 position request . 43
6.4.13 APP – Lift axle 2 position request . 43
6.4.14 APP – Lift axle 3 position request .44
6.4.15 APP – Lift axle 4 position request .44
6.4.16 APP – Lift axle 5 position request .44
6.4.17 APP – Lift axle 1 position . 45
6.4.18 APP – Lift axle 2 position . 45
6.4.19 APP – Lift axle 3 position . 45
6.4.20 APP – Lift axle 4 position .46
6.4.21 APP – Lift axle 5 position .46
6.4.22 APP – Steering axle locking request .46
6.4.23 APP – Steering axle locking status . 47
6.4.24 APP – Traction help (load transfer) request . 47
6.4.25 APP – Traction help (load transfer) status .48
6.4.26 APP – Ride height request .48
6.4.27 APP – Ride height level .48
iv
PROOF/ÉPREUVE © ISO 2022 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 11992-2:2022(E)
6.4.28 APP – Normal level .49
6.4.29 APP – Ramp level request .49
6.4.30 APP – Ramp level .49
6.4.31 APP – Ramp level position .50
6.4.32 APP – Ramp level storage request .50
6.4.33 APP – Ramp level storage status .50
6.4.34 APP – Stop level change request . 51
6.4.35 APP – Stop level change request acknowledge . 51
6.4.36 APP – Parking and towed vehicle air pressure . 51
6.4.37 APP – Auxiliary equipment supply pressure . 52
6.4.38 APP – Tyre pressure threshold detection . 52
6.4.39 APP – Air leakage detection . 53
6.4.40 APP – Tyre temperature . 53
6.4.41 APP – Tyre module power supply status .54
6.5 APP – Axle load parameter specification .54
6.5.1 APP – Axle load .54
6.5.2 APP – Axle load calibration data storage request .54
6.5.3 APP – Axle load calibration data storage status . 55
6.5.4 APP – Axle load measured by external scale. 55
6.5.5 APP – Axle load measured by towed vehicle .56
6.5.6 APP – Axle load calibration data load level .56
6.5.7 APP – Axle load calibration type . 57
6.5.8 APP – Maximum driven axle load . 57
6.6 Ride height parameter specification .58
6.6.1 APP – Extended ride height and ramp level storage .58
6.6.2 APP – Ride height and ramp level set request .58
6.6.3 APP – Ride height storage request .58
6.6.4 APP – Ride height storage . 59
6.6.5 APP – Neutral gear request . 59
6.6.6 APP – Rear obstacle distance . 59
6.6.7 APP – Immobilizer status .60
6.6.8 APP – Fifth wheel load .60
6.6.9 APP – Ambient air temperature . 61
6.6.10 APP – Parking brake status . 61
6.6.11 APP – Neutral gear status. 61
6.7 APP – Software update parameter specification . 61
6.7.1 APP – Vehicle software update request . 61
6.7.2 APP – Vehicle software update request acknowledgement . 62
7 APP – PG specification .62
7.1 APP – Overview of PGs . 62
7.2 APP – Message transmission in case of multiple towed vehicles .64
7.3 APP – Towing vehicle .64
7.3.1 APP – General specification .64
7.3.2 APP – General PGs, transmitted from the towing to the towed vehicle .65
7.3.3 APP – Electronic brake system PGs, transmitted from the towing to the
towed vehicle .65
7.3.4 APP – Running gear equipment PGs, transmitted from the towing to the
towed vehicle . 67
7.4 APP – Towed vehicle . 70
7.4.1 APP – General PGs, transmitted from the towed to the towing vehicle . 70
7.4.2 APP – Electronic brake system PGs, transmitted from the towed to the
towing vehicle . 70
7.4.3 APP – Running gear equipment PGs, transmitted from towed to towing
vehicle . 75
8 APP – Address assignment .78
8.1 APP – General requirements . 78
8.2 APP – Road train configuration . 79
v
© ISO 2022 – All rights reserved PROOF/ÉPREUVE

---------------------- Page: 5 ----------------------
ISO 11992-2:2022(E)
8.3 APP – Address assignment method of a towing and towed vehicle .79
8.4 APP – Vehicle node capabilities .80
9 SI – Service interface definition between application and OSI layers .82
9.1 SI – A_Data.req, A_Data.ind, and A_Data.con service interface .82
9.2 SI – A_Data.req, A_Data.ind, and A_Data.con service interface parameter mapping .82
9.3 SIP – Service interface data type definitions .83
10 AL – Application layer .83
10.1 AL – Message PDU format .83
10.2 AL – A_PDU specification .83
11 PL – Presentation layer .
...

TC /SC
Date:  2022-11-30
ISO/PRF 11992-2:2022(E)
TC /SC /WG Date: 2022-12-15
ISO 11992-2:2022(E)
ISO/TC 22/SC 31/WG 4
Secretariat: DIN
Document type:
Document subtype:
Document stage:
Document language:

---------------------- Page: 1 ----------------------
Road vehicles — Interchange of digital information on electrical
connections between towing and towed vehicles — Part 2: Application layer for
brakes and running gear
Véhicules routiers — Échange d'informations numériques sur les connexions électriques
entre véhicules tracteurs et véhicules tractés — Partie 2: Couche d'application pour les
équipements de freinage et les organes de roulement
Document type:
Document subtype:
Document stage:
Document language:

---------------------- Page: 2 ----------------------
ISO 11992-2:2023(E)
COPYRIGHT PROTECTED DOCUMENT
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or
utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be
requested from either ISO at the address below or ISO’s member body in the country of the
requester.
ISO copyright office
Ch. de Blandonnet 8 •• CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
[e-mail]
www.iso.org
www.iso.org
© ISO 2023 – All rights reserved
iv

---------------------- Page: 3 ----------------------
ISO 11992-2:2023(E)
Contents Page
Foreword . vii
Introduction . viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 4
4.1 Symbols . 4
4.2 Abbreviated terms . 4
5 Conventions . 5
6 APP – Parameter specification . 5
6.1 General definitions . 5
6.2 APP – Identification parameter specification . 6
6.2.1 APP – Axle/wheel identification . 6
6.2.2 APP – Identification data index . 8
6.2.3 APP – Identification data indexed content . 9
6.3 APP – Braking systems parameter specification . 10
6.3.1 APP – Park brake demand relative pressure . 10
6.3.2 APP – Service brake demand pressure . 10
6.3.3 APP – Vehicle service brake status . 11
6.3.4 APP – Braking system wheel-based vehicle speed . 11
6.3.5 APP – Vehicle retarder control status . 11
6.3.6 APP – Retarder demand relative torque . 12
6.3.7 APP – Retarder wheel torque reference . 13
6.3.8 APP – Retarder relative peak torque . 14
6.3.9 APP – Retarder actual maximum positive torque . 14
6.3.10 APP – Retarder actual maximum negative torque . 15
6.3.11 APP – Axle load sum . 15
6.3.12 APP – Pneumatic supply pressure . 15
6.3.13 APP – Brake lining . 16
6.3.14 APP – Brake temperature . 16
6.3.15 APP – Tyre pressure . 16
6.3.16 APP – Automatic towed vehicle braking status . 17
6.3.17 APP – Vehicle ABS status . 17
6.3.18 APP – Vehicle electrical supply status . 18
6.3.19 APP – Vehicle pneumatic supply status . 18
6.3.20 APP – Spring brake installation status . 18
6.3.21 APP – Electrical load proportional function installation status . 19
6.3.22 APP – Load proportional function installation status . 19
6.3.23 APP – ABS off-road request . 19
6.3.24 APP – ASR brake control status . 20
6.3.25 APP – ASR engine control status . 20
6.3.26 APP – Pneumatic control line status . 20
6.3.27 APP – Two electrical circuits brake demand status . 21
6.3.28 APP – Tyre pressure status . 21
6.3.29 APP – Brake lining status . 21
© ISO 2023 – All rights reserved
v

---------------------- Page: 4 ----------------------
ISO 11992-2:2023(E)
6.3.30 APP – Brake temperature status . 22
6.3.31 APP – Brake light switch. 22
6.3.32 APP – Vehicle type . 22
6.3.33 APP – Red warning signal request . 23
6.3.34 APP – Amber warning signal request . 23
6.3.35 APP – Electrical supply of non-braking systems status . 24
6.3.36 APP – Loading ramp approach assistance status . 24
6.3.37 APP – VDC active . 24
6.3.38 APP – Road curvature . 25
6.3.39 APP – Wheel speed difference main axle . 25
6.3.40 APP – Supply line braking . 26
6.3.41 APP – Spring brake status . 26
6.3.42 APP – Relative brake demand for front or left vehicle side . 26
6.3.43 APP – Relative brake demand for rear or right vehicle side . 27
6.3.44 APP – Support of side- or axle-wise brake force distribution . 27
6.3.45 APP – Lateral acceleration . 27
6.3.46 APP – Stop lamps request . 28
6.3.47 APP – Braking via electric control line support . 28
6.3.48 APP – Geometric data index . 28
6.3.49 APP – Geometric data indexed content . 29
6.3.50 APP – Brake cylinder pressure first axle, left wheel . 33
6.3.51 APP – Brake cylinder pressure first axle, right wheel . 33
6.3.52 APP – Brake cylinder pressure second axle, left wheel . 34
6.3.53 APP – Brake cylinder pressure second axle, right wheel . 34
6.3.54 APP – Brake cylinder pressure third axle, left wheel . 35
6.3.55 APP – Brake cylinder pressure third axle, right wheel . 35
6.3.56 APP – Wheel speed first axle, left wheel . 35
6.3.57 APP – Wheel speed first axle, right wheel. 36
6.3.58 APP – ROP system status . 36
6.3.59 APP – YC system status . 37
6.3.60 APP – Towed vehicle ROP system request . 37
6.3.61 APP – Towed vehicle YC system request . 37
6.3.62 APP – Vehicle combination ABS status . 38
6.3.63 APP – Towed vehicle detection status . 38
6.3.64 APP – Reverse gear status . 38
6.3.65 APP – External brake request status . 39
6.3.66 APP – Emergency braking status . 39
6.4 APP – Running gear equipment parameter specification . 40
6.4.1 APP – Driven axle load . 40
6.4.2 APP – Nominal vehicle body level, front axle. 40
6.4.3 APP – Nominal vehicle body level, rear axle . 40
6.4.4 APP – Relative vehicle body level, front axle . 41
6.4.5 APP – Relative vehicle body level, rear axle . 41
6.4.6 APP – Level control request . 42
6.4.7 APP – Level control status. 42
6.4.8 APP – Level change request, front axle . 42
6.4.9 APP – Level change request, rear axle . 43
6.4.10 APP – Level change status, front axle . 43
6.4.11 APP – Level change status, rear axle . 43
6.4.12 APP – Lift axle 1 position request . 44
6.4.13 APP – Lift axle 2 position request . 44
6.4.14 APP – Lift axle 3 position request . 44
6.4.15 APP – Lift axle 4 position request . 45
© ISO 2023 – All rights reserved
vi

---------------------- Page: 5 ----------------------
ISO 11992-2:2023(E)
6.4.16 APP – Lift axle 5 position request. 45
6.4.17 APP – Lift axle 1 position . 46
6.4.18 APP – Lift axle 2 position . 46
6.4.19 APP – Lift axle 3 position . 46
6.4.20 APP – Lift axle 4 position . 47
6.4.21 APP – Lift axle 5 position . 47
6.4.22 APP – Steering axle locking request . 47
6.4.23 APP – Steering axle locking status . 48
6.4.24 APP – Traction help (load transfer) request . 48
6.4.25 APP – Traction help (load transfer) status . 48
6.4.26 APP – Ride height request . 49
6.4.27 APP – Ride height level . 49
6.4.28 APP – Normal level . 50
6.4.29 APP – Ramp level request . 50
6.4.30 APP – Ramp level . 50
6.4.31 APP – Ramp level position . 51
6.4.32 APP – Ramp level storage request . 51
6.4.33 APP – Ramp level storage status . 51
6.4.34 APP – Stop level change request . 52
6.4.35 APP – Stop level change request acknowledge . 52
6.4.36 APP – Parking and towed vehicle air pressure . 52
6.4.37 APP – Auxiliary equipment supply pressure . 53
6.4.38 APP – Tyre pressure threshold detection . 53
6.4.39 APP – Air leakage detection . 54
6.4.40 APP – Tyre temperature . 54
6.4.41 APP – Tyre module power supply status . 55
6.5 APP – Axle load parameter specification . 55
6.5.1 APP – Axle load . 55
6.5.2 APP – Axle load calibration data storage request . 55
6.5.3 APP – Axle load calibration data storage status . 56
6.5.4 APP – Axle load measured by external scale . 56
6.5.5 APP – Axle load measured by towed vehicle . 57
6.5.6 APP – Axle load calibration data load level . 57
6.5.7 APP – Axle load calibration type . 58
6.5.8 APP – Maximum driven axle load . 58
6.6 Ride height parameter specification . 59
6.6.1 APP – Extended ride height and ramp level storage . 59
6.6.2 APP – Ride height and ramp level set request . 59
6.6.3 APP – Ride height storage request . 59
6.6.4 APP – Ride height storage . 60
6.6.5 APP – Neutral gear request . 60
6.6.6 APP – Rear obstacle distance . 60
6.6.7 APP – Immobilizer status . 61
6.6.8 APP – Fifth wheel load . 61
6.6.9 APP – Ambient air temperature . 61
6.6.10 APP – Parking brake status . 62
6.6.11 APP – Neutral gear status . 62
6.7 APP – Software update parameter specification . 62
6.7.1 APP – Vehicle software update request. 62
6.7.2 APP – Vehicle software update request acknowledgement . 63
7 APP – PG specification . 63
7.1 APP – Overview of PGs . 63
© ISO 2023 – All rights reserved
vii

---------------------- Page: 6 ----------------------
ISO 11992-2:2023(E)
7.2 APP – Message transmission in case of multiple towed vehicles . 65
7.3 APP – Towing vehicle . 65
7.3.1 APP – General specification . 65
7.3.2 APP – General PGs, transmitted from the towing to the towed vehicle . 66
7.3.3 APP – Electronic brake system PGs, transmitted from the towing to the
towed vehicle . 66
7.3.4 APP – Running gear equipment PGs, transmitted from the towing to
the towed vehicle . 69
7.4 APP – Towed vehicle . 71
7.4.1 APP – General PGs, transmitted from the towed to the towing vehicle . 71
7.4.2 APP – Electronic brake system PGs, transmitted from the towed to the
towing vehicle . 71
7.4.3 APP – Running gear equipment PGs, transmitted from towed to towing
vehicle . 77
8 APP – Address assignment . 81
8.1 APP – General requirements . 81
8.2 APP – Road train configuration . 81
8.3 APP – Address assignment method of a towing and towed vehicle . 81
8.4 APP – Vehicle node capabilities . 82
9 SI – Service interface definition between application and OSI layers . 84
9.1 SI – A_Data.req, A_Data.ind, and A_Data.con service interface . 84
9.2 SI – A_Data.req, A_Data.ind, and A_Data.con service interface parameter
mapping . 84
9.3 SIP – Service interface data type definitions . 85
10 AL – Application layer . 85
10.1 AL – Message PDU format . 85
10.2 AL – A_PDU specification . 85
11 PL – Presentation layer . 85
Annex A (normative) Geometric dimensions . 86
A.1 Geometrical data definition . 86
A.2 Semi towed vehicle geometric measurements . 86
A.3 Full towed vehicle geometric measurements . 87
A.4 Centre-axle towed vehicle geometric measurements . 88
A.5 Link towed vehicle geometric measurements . 88
A.6 Converter towed vehicle geometric measurements . 89
A.7 Towing vehicle type 1 geometric measurements . 90
A.8 Towing vehicle type 2 geometric measurements . 90
Annex B (normative) Software update request and acknowledge interaction between
towing and towed vehicles . 92
B.1 Towed vehicle system software update . 92
B.2 State machine of towed vehicle . 93
B.3 State machine of towing vehicle . 95
Annex C (informative) Message flow . 100
C.1 Message flow nodes . 100
C.2 EBS message flow from towing and towed vehicles to successor vehicles . 100
C.3 EBS message flow from towed vehicles to predecessor vehicles . 101
C.4 RGE message flow from towing and towed vehicles to successor vehicles . 102
C.5 RGE message flow from towed vehicles to predecessor vehicles . 103
Bibliography . 105
© ISO 2023 – All rights reserved
viii

---------------------- Page: 7 ----------------------
ISO 11992-2:2023(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,
Data communication.
This fourth edition cancels and replaces the third edition (ISO 11992-2:2014), which has been
technically revised.
The main changes are as follows:
Introduced— introduced requirements structure;
Added— added new parameter specifications;
Added— added new message definitions;
Updated— updated all Figuresfigures;
A list of all parts in the ISO 11992 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2023 – All rights reserved
ix

---------------------- Page: 8 ----------------------
ISO 11992-2:2023(E)
Introduction
The ISO 11992 series specifies the interchange of digital information between road vehicles with a
maximum authorised total mass greater than 3 500 kg, and towed vehicles, including communication
between towed vehicles in terms of parameters and requirements of the lower OSI layers (physical and
data link layer) of the electrical connection used to connect the electrical and electronic systems.
This document is structured according to the Open Systems Interconnection (OSI) Basic Reference
Model, in accordance with ISO/IEC 7498-1 and ISO/IEC 10731,, which structures communication
systems into seven layers. When mapped on this model, the application layer protocol and data link
layer framework requirements specified/referenced in the ISO 11992 series standard are structured
according to .Figure
...