UN R78 — 05 series of amendments

New paragraph 2.33. defines “Disable the antilock brake system”. It means to put the system into a state where it will no longer fulfil the technical requirements in paragraph 9 of Annex 3. In Annex 3, point (a) of paragraph 9.1. now says that the tests are only applicable to the ABS if fitted and enabled. Before, it said “if fitted”. Under point (e), vehicles with driver selectable ABS modes must comply with the technical requirements of this paragraph in all modes where ABS is enabled. An example is a dual channel ABS system whereby the ABS on the rear axle can be disabled.

Paragraph 5.1.16. now says that a means to disable the antilock brake system is not permitted, instead of a means to deactivate it. By derogation, a means to disable ABS is allowed on vehicles with a riding mode selector allowing an “off-road” or “all terrain” mode. The listed provisions must also be met. Before, the derogation referred to vehicles “suitable for off road driving” and to a “single means” to disable the function. Points (i) and (ii) now name the antilock brake system “disable-switch” instead of the “on/off switch”. The prohibition of any software and/or hardware defeat device now covers points (a) to (f).

Under point (d), the function must be automatically enabled when exiting from the “off-road” or “all-terrain” ride mode, or after each start-up. Before, it had to be automatically activated after each start-up of the vehicle, except for restarts after unintentional stalling of the engine. Point (f) is about enabling a functional stage which complies with the anti-lock brake system requirements in paragraph 9 of Annex 3. This must be possible through the single actuation of a control initiating the ABS system start-up procedure. Before, point (g) required that instantaneous re-enablement of a functional stage which complies with anti-lock brake system approval requirements was warranted under all operation modes. This had to be demonstrated to the satisfaction of the certification authority.

When disabled, the antilock brake system function must be indicated by a yellow or amber tell-tale until the ABS is fully functional or operating again. Method (i) is the symbol B.18 in ISO 2575:2010. In method (ii), symbol B.05 is used with the word “OFF” according to Y.01 in ISO 2575:2010, with the tell tales adjacent to each other. Method (iii) is the text “ABS OFF” or “ABS not available”, and method (iv) is the warning lamp of paragraph 5.1.13., continuously activated (lit or flashing). Before, point (e) required symbol B.18 “or any other equivalent unequivocal indication”, or, alternatively, the warning lamp of paragraph 5.1.13. continuously activated.

Under new paragraph 5.1.18., a vehicle with ABS active on both axles may have a rider selectable mode that deactivates the rear-axle ABS function. Then a yellow or amber tell-tale or check control messages must indicate this, until the ABS is fully functional or operating on both axles again. Method (i) uses symbol B.18 with the word “REAR” adjacent to it. Method (ii) uses symbol B.18 with a symbol of the vehicle adjacent to it, with an arrow pointing to the rear axle. Method (iii) uses symbol B.05 with the word “REAR OFF” adjacent to it. Method (iv) is the text “REAR ABS OFF” or “REAR ABS not available”, and method (v) is the warning lamp of paragraph 5.1.13., continuously flashing.

Paragraph 5.1.15. applies if a vehicle is equipped with the means to indicate emergency braking. The signal must then only be generated by the application of any service braking system, when the conditions in paragraphs 5.1.15.1. through 5.1.15.2. are fulfilled. Under paragraph 5.1.15.2., the signal may be activated above 50 km/h when the antilock system is fully cycling and deceleration is at least 2.5 m/s2. It must be deactivated when the antilock system is no longer fully cycling. Under paragraph 5.1.15.3., the signal may come from a predicted deceleration from the braking demand, respecting the activation and de-activation thresholds of paragraph 5.1.15.1. Deleted point (b) also said: “The deceleration may be generated from the prediction described in point (a).”

From the entry into force of the 05 series, no Contracting Party may refuse to grant or accept 05 series type approvals (para. 9.5.). As from 1 September 2023, Contracting Parties need not accept type approvals to the preceding series first issued after that date (para. 9.6.). Under paragraph 9.8., Contracting Parties must continue to accept such approvals and extensions for vehicle types not affected by the 05 series changes. Contracting Parties must not refuse to grant type approvals according to any preceding series, or extensions of them (para. 9.9.). The Annex 2 example texts now refer to the 05 series instead of the 03 series, with approval number 052439 instead of 032439.