TRYING TO MAKE SENSE OF MERCEDES DIAGNOSTICS. A LONG WAY FROM KANSAS.

I remember when I started my automotive diagnostic journey about 12 years ago when I first started understanding what OBD is and why it exists. It was definitely a new thing for me, coming from an IT/ hobby mechanic background you would think it would have been easy for me to make sense of the details of automotive diagnostics, but alas. So, I bought myself a few books and started reading. The first book was the Haynes Engine Management one. This was the foundation for me, I then kept reading and trying to understand and with every chapter I ticked off all that I did was begin to understand how I know nothing, John Snow. As time went on, I was slowly but surely building my confidence and my 2016 I was at the point where I had a bit more confidence but as a 27-year-old I think I was also a tad cocky based on the tiny bit of knowledge that I had acquired.

I believe I found myself in Frankfurt for an Automechanika, speaking to one of you guys, an older, much more experienced guy, and I was really brought back to earth. We had just released the FBS3 key and DAS module programming, and I had confidence in abundance then. The guy was really calm and knowledgeable and basically took me by the hand and took me to school. I remember on the flight back thinking there was no way – I had done all the procedures and learned all there is to know about key passwords and service passwords and SSIDs and EHS numbers and IR password extractions and coding and file types, yet this guy calmly and surely destroyed the bubble of a world I had created. I needed to learn. The moment the plane touched down I went back to reading and testing and trying and experimenting. Eventually, like a boxer who had lost a major fight I got back on my feet, this time slightly more cautious and relaxed, I got better. I thought I had overcome this fall. Until a few months ago I had built up my confidence once again. Then, as life often does, another spanner got thrown in. “Aha!” I exclaimed! My previous life experience had put me in this situation once before. I know just what to do. Instead of searching online and going back into my old timey books I went straight to the experienced guys. One of them is the owner of Abrites, a man I owe a lot to and yet I was back at his doorstep trying to acquire a bit more knowledge. He knew very well what was up. So, he tried shoving a bit of information into my head. I thought I had it. It felt like Ayahuasca, the universe was once again speaking to me. I then tried writing a couple of blog posts to you guys about it, about FBS4 but I soon realized that I had not even scratched the surface. There I was – humble pie on my plate once again. Under the layers of module protection and secondary and third layer passwords and remote diagnostics and Xentry online only accesses and endless interweaving connection between ABS sensors and parking assistants with massaging seats I found myself lost again. I had this intrusive thought in my mind about the Wizard of Oz. “Toto, I've a feeling we're not in Kansas anymore.”
https://www.youtube.com/watch?v=uPnfuczOWb8&ab_channel=BestPartsofMovies

After realizing that I got put in Dorothy’s shoes once again there were two ways I could go:
A. Turn into and an old man who just keeps reminiscing about the days of old and blabbers to a bunch of kids at a pub until he falls asleep at the counter. Or:
B. Pull myself by the bootstraps and keep learning so that I could spread the word to everyone who would listen (or read the stuff I write) .
I chose “B”. Late last year I wrote a blog post about the MN034 license HERE.

This gave us a brief overview of what the Personalization expert will be able to do but I only had basic knowledge on what needs to be done then and I seem to have left information out. Shortly after the blog post came out exactly two months ago there was another event that occurred. A car showed up. I am not going to surprise anyone when I say that we have a “rotation of cars” around here – Abrites purchases cars to test and develop on. For most other brands we can make do with purchasing sets of modules from damaged cars to do testing on but in the case of Mercedes we must have complete cars. And the one we got has all that we need. The reason why we must have complete cars for Mercedes is because NOTHING in Mercedes works on its own, everything is a system, and everything is intertwined with everything else. The modules from FBS4 are only useful when you have the car there with you. Even if you have all the modules in the world. This is what warrants the purchase and rotation of many MB cars here which allows us to test all the modules together while in a system.

Let’s try and make some sense of the connections between the systems in modern Mercedes cars. Let’s split them and try taking them in in bite size chunks. It would certainly appear that the modules from the DAS system are interconnected with the ones from the safety system although the safety system does not come with service passwords for adaptation they influence the Engine Control Modules, Transmissions, EZSs, etc. This can be observed while disconnecting small parts like sensors and seeing that the adaptations do not go through. Mercedes was clever when they upgraded the FBS4 system last year – they added an additional password, or should I say, an additional requirement for adaptation. This requirement involves the following rule:

One module from the DAS system is locked to one chassis and you cannot virginize, cannot reuse, cannot adapt if the car has been updated by an MB dealer. A very smooth move on their part, this means that the customer could ONLY go to the dealer and order a new module which needs to be ordered by the dealer to the MB suppliers, brought to the car and programmed. This process normally takes at least a month to complete. You can imagine that the Mercedes owner whose car needs a module replacement has to simply push it away in a corner and drive around in a Toyota Corolla for the time being. Not ideal.  The dealership does not really care - they have done what they have to do – they have ordered the part, scheduled the customer for a visit in the middle of April and have continued on their merry way. The inconvenience is left to the customer. This is where you step in because not all MB owners have a Corolla laying around for a rainy day. There is an opportunity for guys and gals like us to swoop in and perform the adaptation.

Since the FBS4 system is already complicated enough we can only wonder why Mercedes went to such great lengths to double protect it and lock all its modules to a single vehicle effectively turning the protection into a Christopher Nolan film of layers which have to be pealed away. DAS4 is twice as complex as DAS3 and one would think it would be enough. The fact is that they changed it just as the previous MN032 was getting traction. Appears the goal was to make the DAS4 Manager function useless so only MB dealers could perform module adaptations. If I was to speculate on a conspiratorial note.

The situation above required us to develop the MN034 - FBS4 personalization expert license (by the way, it is free for all of you who purchased the MN032 before December 13, 2023) so that we could combat this other layer of protection. Our goal with the MN034 license is to provide an independent, transparent in its purpose tool which allows you to adapt modules. For the moment we have the following key objectives:

1. Allow you to read the personalization data by OBD, without the need for disassembly and opening of the modules for as many modules as possible.
2. If we have a virgin module, we want you to be able to throw it in the car and personalize it, once again by OBD or with minimal additional input on your behalf.
3. Being able to transform used modules into virgin ones on bench or using the vehicle’s internal CAN bus to perform this action. This allows you to overcome the limitations of locking a module to a VIN. We are still battling limitations there because this is the hardest part of the equation. There are still some unknowns which will be overcome soon enough.
4. Have the ability to read electric and hybrid Mercedes modules’ personalization data without the requirement to disassemble them. This is vital for warranty purposes and also very important for safety reasons, imagine if you need to reseal the high voltage part of the battery pack and you miss a spot – this will be on the news sooner rather than later.
5. Let Mercedes be VIN bound for all their DAS/ FBS4 modules while allowing our customers to exchange modules from one car to another.
6. VGS4 NAG2 – the Kryptonite  of any current Mercedes owner’s daily work. We are still exploring the situation and will let you know later on.
7. 8G-DCT support will soon be available. I was really impressed when I first read this article about the official launch of this transverse transmission which is meant to be coupled with the OM654 2 liter diesel engines. The fact that the manufacturing is in Romania was equally as impressive to me as I have a lot of respect for the Romanian automotive industry. If you have a moment take a look.
https://mercedesblog.com/mercedes-benz-has-inaugurated-production-of-the-new-8g-dct-gearbox/
8. 48V system components. The mild hybrid systems in Mercedes are really impressive, they may have been late to the game (as they were with BEVs) but they are finding their footing with the 48V systems. They are pretty well integrated to assist fuel economy, provide an F1 like boost of power and expand the range of the vehicles. The 48V system is now incorporated in the sedans as well as SUVs and  even in the E-performance AMG models. Interestingly all the components – batteries, motors and controllers are part of the DAS system which combined with defects in production is a recipe for you to take advantage of the situation and help out with replacement should your customers need it. Battery repair and replacement is a hot topic now as the first cars using the 48V system are coming out of warranty, this is where we at Abrites come in to help you help your customers.
9. Engine Control Units. We have discussed the supported list of engine control modules in the previous article on the MN034 Personalization Expert quoted above. For the moment we are still on track to support them but I am certainly going to tell you when more modules are added but we simply cannot insert all of them at once. This is a continuous process and we want to know what other modules you see in your line of work with the Personalization expert. We can safely say that modules are grouped and when one type is supported there is probably a different module which complies with the same rules of adaptation. Interestingly for the moment we still have the:
∙ Ability for personalization of all types of virgin ECUs with previously available personalization data unsupported for bench programming (EMS74, MRD1, MRG1 - year 2021+)
∙ Personalization of MED177, MED40, CR60LS ECUs when NO PREVIOUSLY PERSONALIZATION DATA IS AVAILABLE!

I must say – we got a bit carried away this week but I just want you to have the information I now have as the tool develops. We have always taken pride in our attempts to be as transparent with our customers as possible, we want you to know what we know which is why this blog exists and my job is to provide this information to you.

Until next week, try to have fun at work!
Alek