It is a topic as old as time if time began in 2015. Ever since then the whole world has been asking the same question. How do we program keys to FBS4 cars? The short answer is – we don’t. But what if there is another way?
I. What can we do so far?
At the moment using the Abrites MN032, MN034, MN039 and MN040 licenses we can do adaptations for many important DAS4 modules – most of the Engine controllers, including MRD1, MRG1MED17, EDC17, SID310, Delphi-CRD3 ECUs, (CR40, CR41, CR42, CR43, CR6, CR60, CR61, MED40, MED41, MED177, MED1773, MED1775, CRR1, CRR1+, CRD3, CRD3S2), also the ones which are associated with //AMG cars as well.
DSM programming was also introduced by the ABRITES FBS4 manager, as well as 48V starter generators and Hybrid inverters.
We have support for the VGS3NAG3 9G- tronic VGS by Bosch, the VGS4-NAG2 by Continental, the FDCT in 9 and 7 speed trim but by far this year’s greatest success was the ability to virginize and program the VGS4-0-NAG2 by direct CAN connection with and without previously saved data. Don’t forget support for the AMG Speedshifts and the transaxle in Aston Martins, AMG GTs as well as the often overlooked ELV support.
All this brings us to the conclusion that the best tool for FBS4 can be only one- Abrites. This comes as no surprise – we were the ones who created DAS management as a concept and since 2015 have been the unequivocal leader in the world of DAS module adaptation. You may think it sounds boastful, but it is the truth. We have made great progress over the past couple of years, but I assure you that we have been working on the matter since the first FBS4 came out in 2014. Through numerous test cars and thousands of hours of work we are now at this point. The only solution proven to work as advertised (Jeremy Clarkson voice) “In the World”
II. Where do we go from here?
At first glance the only logical solution would be to go for key programming. As a matter of fact, however, it is not that simple. We know how to program a key for an FBS4 car, but it takes years per key. This obviously means that the cars will grow old before they get their new key. For this reason, we have to figure out a more viable way to program a key to those cars. “BUT HOW?” you may ask? There is no car key programming tool to do that. No matter what fake videos from questionable channels on YouTube show. For the moment the car key programming tool world has no answer to the billion-dollar question.
Since real key programming like the one we at Abrites invented for FBS3 back in 2015 is not possible we need to find a workaround. What is this workaround?
At the moment our workaround allows us to do programming of used EZS (EIS) modules which already have keys programmed to them (taken from a scrap yard or bought online from a suitable donor vehicle and have that programmed to the car. We at Abrites have successfully demonstrated that. The problems stemming from that form of programming mean that although the car starts and runs successfully there are many problems it causes in the operation of the vehicles. The coding of the donor Electronic Ignition Switch will inherently be different to the one in the car which is due to two factors – the VIN number and SSID mismatch between the donor and recipient. This causes malfunctions in the vehicle and so on. This brings us to the solution we propose and the one we are still working on – the ability to replace the ignition switch with a used one requires the VIN and SSID to be changed. This is a feat which no key programming tool or any tool for that matter being able to do. We are hard at work making it happen and we will certainly achieve this goal.
III. In conclusion
The evolution of vehicle security has reached a pinnacle with the Mercedes-Benz FBS4 (Fahrberechtigungssystem), a multi-layered cryptographic framework introduced around 2015. Unlike its predecessor, FBS3, which allowed for local key generation and offline module adaptation, FBS4 relies on server-based authorization and 128-bit encryption. This shift was designed to eliminate key cloning and unauthorized module swaps by “marrying” every major component—the Electronic Ignition Switch (EIS), Engine Control Unit (ECU), and Transmission Control Unit (TCU)—directly to the vehicle’s VIN through Mercedes’ central servers.
For the independent aftermarket, this system initially presented a “dealer-only” barrier. However, specialized diagnostic tools have bridged this gap by focusing on module replacement and personalization. While physical key programming for FBS4 remains highly restricted due to the requirement for factory-signed data, advanced software now allows technicians to virginize and adapt used FBS4 modules. By extracting personalization data from original units or generating new data for virgin components, professionals can now perform complex repairs, such as ECU and TCU swaps, without requiring a direct link to the manufacturer’s online infrastructure, effectively returning serviceability to the independent workshop.
