Hmmm, might be the tires, since unless I am missing something, the numbers does look normal/healthy. I got an idea, try putting vehicle in esc sport or esc off altogether, it might be limiting power.

What tire pressures do you have on the vehicle, measured when cold? When cold, use the tire pressures on the fuel door cap, also I forgot to ask which codes remained after you cleared them last?

What tires are on the vehicle? The sizes, etc.

If you haven't already, you could consider switching to Michelin Pilot Sport 4S.

Hey,

You might be right, I think my numbers are healthy if you also think so. I had new PS AS4 tires (245/40ZR18 XL) installed before the summer. Shop had the pressures set at 38-40PSI on the front and backs (all around). Do you know what the most optimal pressure numbers would be?

Also I will be clearing the codes this evening and checking after a few to ensure which codes stick around.

Thanks again for your time and support!

You're welcome : ) Keep me updated on the code situation.

Check the gas fuel door, those are the pressures to use. Don't use the ones on the doorsills, remember to check these pressures when cold, it is cold tire pressure. Just check it the first thing in the morning.

There are 3 types of pressures, low load, high load and M+S tires. There is one more but only C 63 S has it I think, it is tire pressures based on speed.

Hey,

So after clearing the codes (was able to clear all the codes listed in my earlier post, with the expection of U012287), I have not had any codes resurfaced.

Does anyone know what U012287 is attempting to flag? I am unable to clear this code and from many posts on this site and other forums it seems to point to the AMG drive unit but am unsure.
Link to similar post (W205C43PFL you had mentioned that this poster had some rodent infestation I am unsure that this was the case as the solution was to unplug/replug the drive unit): https://mbworld.org/forums/c450-c43-...o-codes-3.html

Furthermore, please find attached images of tire pressure ratings and currently cold pressures in images below.





Am I right to say that the car should be 42 PSI cold fronts and 33 PSI cold backs given R18?

Sorry, it was this thread: https://mbworld.org/forums/c450-c43-...edan-w-pe.html

As for the tire pressures, there is a problem though. It is inconsistent, see this thread: https://mbworld.org/forums/c450-c43-...ml#post8137774

There are two stickers (and part numbers):
A 205 584 64 11
A 205 584 65 11
The thing is, these two stickers are showing these differences in between model years and/or the same exact model years. The sedan and coupe usually have different pressures but these are all the sedans.
You could try using the one on your fuel cap door or those new lower values and see what works the best for you.

OP, sorry for reviving an old thread, but I have the same exact issue as yours.
My 2020 C43 can only get up to 325-340ish in Sports+. I believe the previous owner had an issue with bad battery and replaced it, but never cleared the codes (my regular mechanic confirmed that the battery was replaced around May 2025). I also tested the battery on the cluster and getting 12.5v during idle and around 14.5v with the engine on. I was able to clear all the stored codes except the U012287.

Did you ever clear the U012287 code? If so, what was the fix for you?

Thank you!