Haldex SUMS ensures compliance with new EU regulations or trailer type approval

Haldex supplies its Software Update Management System (SUMS) as part of a package with its braking systems, helping trailer OEMs to remain compliant with the latest EU regulations, which now mandate such software as part of a vehicle or trailer type approval.

Since the passing of EU R156 in July 2024 all new vehicle types brought into use on EU roads since then are required to have SUMS. There was a two-year grace period to retrospectively add SUMS, but with this expiring in July 2026 any new vehicles or trailers without it could be refused the plate needed to put them into service. And so, it is now an integral part of the type-approval process.

“The intention of the legislation is to maintain the vehicle throughout its lifetime in compliance with its original type approval,” says Alexander Kraus, product manager for electronic braking systems at Haldex. SUMS is a way of automatically overseeing software so that no changes are allowed to alter a vehicle’s approved functionality without the manufacturer’s knowledge and sign-off. 

Haldex SUMS works as a web-based portal: a manufacturer registers as a company, adds its own users, and then maintains a database that records each trailer by its vehicle identification number and ties it to the braking device installed and that device’s software level.

A companion regulation, R155, covers cyber security management; it is not yet in scope for trailers, though the two are closely linked.

Why the rules matter

Kraus offers a concrete example that illustrates the reason the rules are needed. Tyre pressure monitoring has been mandatory on trailers and commercial vehicles since 2024, and it is connected to the braking system, which in turn feeds information to the driver. In theory, an electronic brake system supplier could issue a software update that disables the monitoring gateway, which would leave a legal safety function inoperative, potentially without the OEM ever knowing.

R156 is designed to remove the possibility of exactly this type of scenario. Manufacturers must record the initial hardware and software state of every electronic unit on the vehicle, and every subsequent update must be documented, tested and approved before it reaches the field.

R156 and R155 apply to vehicle manufacturers, not to component suppliers. A supplier such as Haldex cannot have its systems type-approved in isolation, but it can have them independently certified. This is why Haldex is approved to ISO 24089 for SUMS, and is going to be approved to ISO 21434 for cyber security in the future. The certification then supports the OEM’s own compliance case.

Not all manufacturers and suppliers yet have these certifications. “Some manufacturers are much further advanced and have already certified themselves; others are still working through the legislative hurdles,” says Kraus. Those not yet ready can fall back on national individual approval rather than full EU type approval, which is a workaround, but not a long-term answer.

How the platform works

Once logged into Haldex SUMS, a manufacturer can see every trailer it has built with a Haldex braking system, along with the configuration of each. “It’s a large database that records the trailer, the devices installed on it and the related software level,” says Kraus.

Security comes from locking that configuration. When the braking system is installed and set up an operative can see all key braking parameters including laden and unladen weights. The settings can be locked manually, and the system locks them automatically after 500 kilometres in any case. After that, nothing can be changed without authorisation. If an update or a parameter change is needed in the field, the user raises a change request, and the relevant person at the vehicle manufacturer receives a prompt to approve it or decline.

There is a trade off in terms of the time needed. “The system is secure and you can see what has been changed in the past, but it slows the process down a little, because it has to be online and someone has to approve the change.” But for type approval, this traceability is now vital.

The Haldex platform is not mandatory. OEMs can build their own SUMS, and some have; a few could even keep records in what Kraus calls “an advanced Excel sheet”. The catch is that such an approach offers no automatic update notifications and no visibility of whether updates are even available.

Cyber security as the next layer

Although the cybersecurity regulation R155 does not yet apply to trailers, Haldex is pursuing ISO 21434 certification anyway. New-generation hardware adds a microprocessor capable of encryption, and the company has introduced signed bootloader software (key encryption built in at the boot-up stage), which proves that the software you are trying to update on the device is coming from the correct source. Manipulated or counterfeit software cannot be loaded onto the device.

Cybersecurity is becoming ever-more important in an increasingly connected world. And with increasingly automated systems within vehicles vulnerability points are growing, making ransomware attacks a genuine concern. “Imagine someone hacks into your braking system and prevents the vehicle from braking, then tells you the trailers aren’t moving until you pay,” says Kraus

Getting started

Onboarding of Haldex SUMS is designed to be light. Registration takes around five minutes, after which the first user becomes the account administrator and can create and edit further users. Initial account set-up runs through the Haldex service desk, which aims to respond within 24 hours, and a user guide sits on the portal’s homepage, with a support team handling questions, and both initial and on-site advanced training are available.

Parts installed before the legislation came into effect are not locked and can be handled as before. Parts installed and configured after it need to be brought onto the platform, with the vehicle manufacturer claiming the part as its own; from there the process matches a new installation, linking the trailer’s VIN to the device. The migration is largely automatic, but it is something OEMs should be aware of as registration becomes mandatory.