My 2020 Mercedes CLS 450 has the COMAND system. The car was in the shop for maintenance and since then the speed limit info displayed on the dashboard is incorrect at some locations. For example, a on street with posted limit of 30 mph, the car shows sections with 25 and 45 mph limits depending on direction of travel. On a street with 35 mph posted limit, the car now shows a section with 80 mph limit. These faulty displays are not consistent. Sometimes they show up, sometimes not. But the car has no problem reading the speed limit signs. These faulty indications happened after the shop visit. I took the car back to the shop but they say 'everything is as designed", which it is not. I have owned the car for 5 years and this has never happened before. What is causing these faulty indications?

 

Russian hackers....(I wish I was kidding). Recently there have been alerts from most every IT security company is freaking out over a number of resources causing ill effects on systems all over the world. Now, if I were a Govt. I would test my system to create havok on GPS systems before I appempted to do something nutty in the world arena. When Russia started their war in Ukraine thousands of network security issues started to have issues that then effected devices world wide (Ukraine Govt used a majority WatchGuard brand secuirty devices).

When I see odd things going on with systems we count on (GPS is a great example), it is not hard to look at a third party who may be causing the confusion on purpose.

The following IP addresses are directly associated with known threat actor activity. Outbound connections to these IPs are a strong indicator of compromise. Inbound connections from these IPs could indicate reconnaissance efforts or exploit attempts.

• 45.95.19[.]50
• 51.15.17[.]89
• 172.93.107[.]67
• 199.247.7[.]82
• 38.252.8[.]14 - Added Dec 29
• 94.249.197[.]106 - Added Dec 29

 

Thanks. But if hackers are involved then lots of Mercedes cars would have this issue, right?

 

Yep, I was being paranoid as we had a ConCall (I was looking at this site on it) going over how these things can alter our business and how it was (in reality) altering how some of our vehicles were showing up on GPS. We got an alert because one of our company vehicles was supposedly doing 113mph across a parking lot that is in some woods (impossible). I have recently seen a ton of nuttty crap on Strava as well, like within the past month.

 

That certainly sounds odd, and my first thought is that something is up with your camera. There's no real telling of if it actually recognizes the speed limit signs. This is because if it can't recognize a speed limit sign, it falls back to the speed limit in the map data. So usually one of two things happens. First option is that it misread the speed limit sign. A common cause of this is a fogged up lens of the camera. Second option is that it didn't recognize the speed limit sign at all, and instead shows you the speed limit from the map data, which could be incorrect, and if the GPS position is somehow off, that could contribute to it as it may show you the speed limit from the wrong road. I have COMAND as well in my 2019 C63S Coupe. Same generation system essentially. TBH, though, I don't pay much attention to the speed limit displayed in the instrument cluster and I don't daily drive my car, so if anything odd is going on, I wouldn't have noticed. The occasional times I've glanced at it, though, it was generally correct. I'm taking it in for the annual service next week, so if I notice anything, I'll post an update.

 

The camera records the speed limits correctly, and with the nav system on at the same time, theh position is correct. So it seems like the location/speed limit data is corrupted. Today, for the first time it indicated a 5 mph limit at a grocery store parking lot. Never seen that before and there are no posted limits at all.

 

Do you have an active Mercedes me connect subscription? What's the last map update that was installed automatically via OTA update or manually by you?

 

I have the subscription. The last OTA update was in November I think. No issues then. But in December my car was in the shop for maintenance and since then the speed limit info is bananas. The MB shop says they did not do anything to cause this and after I took my car back couple of days ago, they checked it, test drove the car, and said everything was as designed. Of course, a test drive means nothing if the data base is correct for the roads they used.

 

It has now been determined that the software loaded by the dealer was corrupted and that Mercedes is working on a fix. As of today no fix is available and MBUSA has not even bothered to reply to several of my e-mails asking about the fix. IMO, this is a traffic safety issue. A car that suddenly accelerates to reach the 50 mph higher false limit, or slows down from 70 mph to a false 25 mph limit could cause accidents. I think MB has lost it. They seem to be more focused on changing the looks of the cars from understated elegance to overstated ugliness inside and out.

 

The car does not suddenly accelerate or decelerate based on what it thinks the speed limit is. It only does that if you are using DISTRONIC and you have the automatic speed limit adoption turned on. This can be turned off in the settings. I've turned this off a long time ago, because even if the speed limit info is working most of the time, it isn't foolproof, so there's always a chance that it gets it wrong. Instead I manually adopt the speed limit, which you can do by pressing RES while DISTRONIC is active. The setting to turn off the automatic adoption of the speed limit is found under the Driver Assistance settings in COMAND. Keep in mind, all these are only driver assistance features. You must remain vigilant and expect that they can fail at any moment and take control if they do.

 

Thanks, but I know how to activate/deactivate the Distronic, Steering assist, HUD, etc. I paid for these options on my loaded 2020 CLS450 (MSRP about $93K) and I expect them to work as intended. There is no excuse for corrupted software and no excuse for dragging the feet to fix it. I have been waiting almost 6 months for a fix. This CLS is my 9th MB (incl four S-Class) and likely my last one seeing how MB is going downhill.

 

Of course there's a reasonable expectation that the features work as advertised, but sometimes they don't or break and need repair. Not sure what this supposed software corruption is about. Haven't heard of a similar case, but software can be buggy. It's unfortunately the nature of things, and Mercedes no longer maintains COMAND. It's several generations old now. I have an annoying bug as well that Mercedes has been unable to fix, unless I pay the dealership to replace the entire COMAND unit, which I'm not going to do. Car is no longer under warranty, so if something breaks, they are not gonna fix it for free at this point. Your corruption could be caused by failing hardware, such as NVRAM faults. It may not just be as simple as uncorrupting the software. You may need new hardware to avoid future corruption. Software doesn't just corrupt by itself. I'm a software engineer by the way. Usually it's data that corrupts due to bugs in the software or failing hardware such as memory and storage faults.

There are several third-party coders active on this website that can remote diagnose software and coding issues and can try to fix it remotely, such as reloading the firmware and redoing the SCN coding. Much cheaper than paying a dealer to try to fix this, but if you are expecting Mercedes corporate to come up with a fix, that's not going to happen. The warranty on your car has expired, and extended warranties don't cover software issues.

 

The software problem must have been caused by incompetence. Programming something that would not work in the Comand system, but downloaded anyway by the MB dealer. There are no excuses for incompetence.

 

What work was performed when your car was in for maintenance? If they installed a software update, then it would say so on the work order. There haven't been updates for this generation of cars as far as I know, especially not for the speed limit info. The only updates for these cars were map updates and those are installed w/o dealer intervention if you have an active Mercedes me subscription.

To give you a bit of an idea based on the issue I've been dealing with for about 2 years now. Well, when I say dealing with, I really mean I've just lived with it and kinda given up on getting it fixed, however I might take another stab at it because of some recent new information. My issue coincidently also started after my car was in for service, but it appears that it was just a coincidence. After about 5 years, my car suddenly seems to have started to lose some regional settings after it's parked for a while. This is most apparent by my speedometer showing km/h instead of mph when this happens, so I have to manually change it back to mph just for it to change back to km/h next time the car is parked for at least an hour or so. My dealership had agreed to reload the COMAND firmware, but that didn't' change anything and afterwards I had a remote coder reload the instrument cluster firmware. It also didn't do anything. So the firmware and coding of the most obvious modules wasn't corrupt. Now that we have all kinds of AI, I recently described the symptoms and attempted fixes to Copilot and it pointed me to something I haven't thought of before. Based on the symptoms it suggested the most likely cause is corruption in the central gateway (CGW). Either corrupt or mismatching SCN coding or the central gateway hardware's NVRAM is failing. Apparently, it's a somewhat known issue that these can fail eventually. Your car has one, too. Same generation as mine. So, Copilot suggested to do a SCN coding alignment across the central gateway, COMAND head unit and the instrument cluster. It's suspecting that there are incorrect regional settings somewhere causing the car to boot up with the default European settings instead of US settings.

I haven't done anything yet with this info, but I'm planning to attempt the suggested SCN coding alignment. If that doesn't fix it, then it's possible that I need a new central gateway.

As I said, hardware can fail over time. That the car was in service before this happens can just be a coincidence. They do hook up the cars to the mothership during service and it performs some diagnostics. It's always possible that this step triggered the failing hardware to finally act up.

 

Oh, I forgot to ask an important question. Have you replaced your main and auxiliary batteries yet? Your car is at the age when these batteries start failing. 4-6 years is the typical lifespan. A failing battery causes voltage instability, which can cause all kinds of electronic gremlins including corruption. I forgot to mention that before I did most of the attempted fixes above, I first replaced the batteries. My main battery was indeed failing. Unfortunately, once something gets corrupted due to voltage fluctuations, just replacing the battery won't fix it. The corruption has to be fixed as well and tracking down what it messed up may not be easy.

Your maintenance visit at the dealership could have stressed an already failing battery as they usually leave doors and hood open.

 

You could be right. The car had no problems at all before the service, but did so afterwards. The MB shop and MBUSA agreed that 'bad' software was loaded. The first indication was switching to 80 mph in a 35 mph zone. It did that a few times, but not lately. Now it switches to 45 or 25 mph in a 30 mph zone, but not consistently -- it does that when driving in one direction, but not in the opposite direction. The speed limit camera is working OK since it switches to the limit posted from a false limit displayed. Sometimes it shows 45 mph on my circular driveway. Once a 5 mph limit on a parking lot with no limit signs posted. Sometimes it can not find a speed limit at all. Sometimes it displays a false value where it worked correctly before, but a correct value when driving thru the same area next time. However, in all cases the location indication on the navigation map has been correct. You never know when and where the next false speed limit indication shows up or how much it will be off, 5 or 50 mph? I've had it with MB. Thinking about notifying NHTSA.

 

Looks like my last post may have crossed with your post. If you haven't seen it, make sure you replace your battery if you haven't done so already. If you still have the original battery, it is most likely failing at this age, and causing electronic gremlins.

 

Thanks, good advice. Both batteries are original. The car has about 24,000 miles.

 

Definitely time for a new battery then. Mine took kind of a nose dive during the lockdowns as I wasn’t driving the car for weeks. Had it periodically hooked up to a battery maintainer, but probably not as much as I should have.

 

Thanks again. I'll look into it.