Multisystemic failure out of nothing.
 

Hi guys. Yesterday after having my car parked for about 3 days, i got several errors uppon engine start up (cranked up like always).
- Lane assist inoperative
- traction control unavailable
- collision prevension assist plus inoperative
- Suspension is stuck in the left side LED and car feels like a rock (like if i had race coilovers)
- Steering is assisted but weird, brake hold (when you press the brake hard on a stop) not working.
All of this out of nothing! any ideas what could be wrong? Car is awful to drive. I can feel every bump or street imperfection.

Regards.

Hey was the car parked in the cold over this period of 3 days? Do you still have all of the issues listed above? It seems as if it may be an electrical issue.

No cold at all. Its heavy summer in here. Car was parked in an undergroung parking. Later today i will borrow a scanner to see if i get something but a couple guys told me it could be a dying battery.

Regards.

Yes, sudden "seemingly random" collection of faults, especially after multi-day parking, has often been reported as the result of a weak/dying battery. If your battery is over 4 years old, or less if the car has often been parked for extended periods without a battery tender, this would be my first suspect.

Today I went to a friend's workshop and made a full scan. It had several errors regarding steering. I cleared them all and now it's back to normal. It really seems it was a low voltage issue although it has cranked fine all the time.
any suggestions on batteries besides original one? (600usd on my local shop)

Regards.

I haven't yet replaced the battery in our 2017 C43 sedan ... it helps that we plug it into a battery charger/tender when it won't be driven for more than a day but I expect to replace within the next year. However, in our 2007 E350 (which also had an AGM battery), I purchased a good brand battery of the proper type/size/classification (in my case from Canadian Tire) that came with a 5-year full-replacement warranty (better than the MBZ 2-year pro-rated warranty). That was in 2015. The replacement battery was less than half the price, had a better warranty and was easy to replace ... personally, I wouldn't let the "techs" at a "store garage" do the swap. A friend now owns the car and I still do much of the regular maintenance on it. In 2023 he/we replaced the 2015 replacement battery and, being a very satisfied customer, purchased the same one.

When I did the first replacement in 2015, AGM batteries were still not that common and my research (at that time) led me to believe that both the MBZ battery and the replacement were made by Exide. AGM batteries are pretty much the norm, at this point, so I'd assume that there now are many manufacturers. As such, I go with any name brand (or branded) that comes with a 5-year full replacement warranty (i.e., not a pro-rated warranty).

In case anyone is interested, here's the user-friendly charger plug-in I installed in the C43 ... needed front access, for the parking in our garage, and opening the hood was a no-go for the "boss lady," so I installed a weather-sealable "cigarette lighter" socket (using Amazon-sourced parts):
https://cimg5.ibsrv.net/gimg/www.mbw...cfc841cb76.jpg

Thanks a lot for your answer. I got a good deal on my Mercedes dealer and got the original one. We reseted the BMS and it's running fine although I got again some errors (less than before) but they went away after driving a couple minutes. This is getting really weird. Could it be a dirty sensor?

Regards.
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I have learned from a variety of cars that spotty batteries can cause all sorts of ghosts.

Sure but yesterday i changed the baterry for an original new one, reseted the BMS but problem persist.

regards.

Well after further diagnosis, steering spring clock is damaged. That's why suspensión is on max stiffness , no lane assist, no collision prevention, etc...I was told there's an expert repairing them and other option is to get a new or used one.
Any good video on how to remove it? I found some videos on YouTube but they are poorly detailed on how to do it.

Regards.

Finally fixed it! It wasnt the spring clock damaged, it was the steering angle sensor optical piece that was pretty dirty and thats why it couldnt read any value. Check this video where its explained how to do it. It took me just a couple hours to fix everything. Now car runs great.
Video if about a CLA (W117) but its the same exact system as W204 and W205.

Hope this will help someone else.

Regards.

I have 9 errors pop up then next time I start it’s 4 then may go away as I drive. Then pop up again next start, I was told all the errors are caused by 1 faulty wheel speed sensor.

Sometimes it's not faulty, it's just dirty.

That's gonna be the accessory battery causing all of those issues. Drive the car a bit, keep the key AWAY from the car when it's parked and it'll go back to normal

Thanks for your answer BigTurbo but problem was steering angle sensor reflective piece being dirty. I attached a picture of the dirty part (circled in yellow). I cleaned it with contact cleaner and a paper towel and voila!

https://cimg9.ibsrv.net/gimg/www.mbw...916352a6f0.jpg

Regards.

Well how about that! Glad you got it figured out and nice to know in case this pops up! Thanks for sharing :zoom:

That's kind of cool, ngl.