This guide provides advice to heavy vehicle owners and operators about when a trailer equipped with an advanced braking system must have the antilock braking system (ABS)/electronic braking system (EBS) electrical plug connected.

As advanced braking systems become more common across the vehicle fleet, operators and drivers are seeking to clarify the requirement on when these advanced systems need to be connected. Questions also arise about the compatibility of advanced braking systems by different manufacturers.

On this page

• What are advanced braking systems
• How does this apply to advanced braking systems?
• Information regarding the compatibility of advanced braking technologies
• Retrofitting ‘through wiring’ and outlets on hauling units
• Resources

What are advanced braking systems

Traditional braking systems are relatively simple and result in the application of a vehicle's brakes in response to a signal from the driver. Over time these systems have evolved to be able to be adjusted based on the load carried on the vehicle (load proportioning) to now more advanced systems that incorporate a number of different functions. Depending how advanced the system is, it is now possible to achieve the following:

• the combination to maintain directional control (steering) under heavy braking
• brake force modulation to maximise effectiveness
• quicker braking response times
• improved brake distribution/balance
• automatic brake applications on the relevant wheels to counteract effects of oversteer, sway and so on.

While these systems are now mandated on newer vehicles, older vehicles can also be upgraded by retrofitting these systems. By upgrading an older vehicle you can potentially greatly increase its ability to handle emergency situations on the road.

How does this apply to advanced braking systems?

The Heavy Vehicle (Vehicle Standards) National Regulation (heavy vehicle safety standards) requires that any equipment fitted to a vehicle must comply with the appropriate standards and be in working order.

The rule of thumb when it comes to connecting a trailer to its hauling unit is that all plugs/lines must be connected if they are capable of being connected.

For traditional trailers without advanced braking systems – all hauling units and trailers will have both air brake lines and a lighting/power electrical plug and both must be connected.

For trailers fitted with an advanced braking system – an additional ABS/EBS plug will also be fitted. As this technology is not fitted to all hauling units, the rule of thumb is if the system can be connected, it must be connected. This means:

• If a trailer with advanced braking systems is coupled to a hauling unit which does not provide a separate ABS/EBS plug to power these advanced systems:
  • the air brake lines and the lighting/power electrical plug must be connected,
  • but as there is no ability to connect the ABS/EBS plug, it need not be connected.
• If a trailer with advanced braking systems is coupled to a hauling unit which does provide a separate ABS/EBS plug to power these advanced systems:
  • the air brake lines, lighting/power electrical plug and ABS/EBS plug must be connected.

Information regarding the compatibility of advanced braking technologies

With a mix of advanced braking system technologies available, ensuring compatibility between systems and assembling the safest possible combination can be complex.

To assist owners achieve best practice, a number of Australia’s leading heavy vehicle industry associations have developed the Guide to Braking and Stability Performance for Heavy Vehicle Combinations.

The guide highlights potential compatibility issues across braking technologies used in different markets (including Australia, Europe, North America and Japan).

Retrofitting ‘through wiring’ and outlets on hauling units

Where a hauling unit (including a dolly or prime mover) does not have an ABS/EBS plug/pass-through wiring and plug to supply power to a trailer’s advanced systems, these connections can be easily retrofitted.

Providing power to the trailer’s advanced system, even when the hauling unit is fitted with a traditional braking system, still allows a number of the trailer’s advanced systems (load sensing, ABS and roll stability) to operate, resulting in a safer vehicle combination.

For further information regarding retrofitting it is recommended that you contact a reputable brake supplier, G2 accredited Approved Vehicle Examiner (AVE) or auto electrician with a good understanding of these advanced systems.

Resources

Chain of Responsibility

The Primary Duty requires Chain of Responsibility parties to ensure, so far as is reasonably practicable, that they carry out their transport activities in a way that ensures public safety when heavy vehicles are used on a road.

Keeping up to date with vehicle standards and implementing them in your fleet is one part of your transport activities.

Complying with the national heavy vehicle safety standards

The operator of a heavy vehicle must ensure that their vehicle complies with the relevant Australian Design Rules (ADRs) and the Heavy Vehicle (Vehicle Standards) National Regulation. Using or permitting another person to use a defective heavy vehicle on a road is an offence.

A defective heavy vehicle is a vehicle that:

• does not comply with the heavy vehicle safety standards; or
• has a part that does not perform its intended function; or
• has deteriorated to an extent that it cannot be reasonably relied on to perform its intended function.

More information can be found at Heavy vehicle defects.

NHVR support

If you have questions or require further information, please contact the Vehicle Standards team.

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