BenzNinja

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and this your dealer can't do

W205C43PFL

Any update from your tuner OP? Is the car fixed yet?

kistiyanpetrov

drop you an PM with more details

W205C43PFL

Got it.

Tallgeese

@kistiyanpetrov Were you able to figure out if that Powertrain update was responsible for your slower response on the pedal?

I fixed the vacuum pump check valve with a replacement from Klifex and my throttle is definitely snappier. Just in case I replaced the boost solenoid as well since many owners on the forums have issues with it. But while my Dragy times have improved it still feels as if the CPC is holding the car back ever since that update.

@BenzNinja Is it really possible to downgrade the CEPC_VC13_0_Star2 to an earlier software version using Vediamo and an official OpenPort? I've done some coding here and there but never flashed a control unit.

kistiyanpetrov

sorry bro i didn't pay attention to the forum for a while, since my post here i remap the car twice and the car is doing max 1.1 bar boost also go up to 3/4 boost, last week i was changed the vacuum pump valve and the car get a bit more responsive in the lower rpm but 3/4 boost still same im considering to check the vacuum valve which go to the turbo and check if this will bring the fix

you can find me on ig: kristiyanpetrov8 if you have any questions, just drop me an msg that you're from the forum

DirtyDD

Good info here. I can confirm that the software update that fixes the jerky S+ behavior is not an ECU tune. My car was tuned on top of a very recent MB software release. Then the dealer had it for a while, reflashed all kinds of their OEM software, but the ECU version was the same when I got it back because the same tune file still loaded fine. Yet the S+ jerkiness is utterly gone. No change to exhaust sounds.

I have the exact same scenario, with the tune loaded the car is definitely way faster than stock, but the boost bar only goes to 3/4. It used to be pegged at max.

D

kistiyanpetrov

I get confused, so you did just the TCU update?

Because on my last visit they update ECU and TCU and since then i can reach full boost

Darrington

I’m bringing my C400 in tomorrow, should I be worried?!

kistiyanpetrov

Are you bring it for update or service A/B, if so tell them to not update it at least if you don't want

DirtyDD

My ECU was up to date. I know because I can load the same tune after the visit as before. They updated other things that fixed the jerky S+ but appears to have altered the boost gauge behavior.

I got almost full boost bar with stock tune, but then loaded stage 1 and the car was way faster but the boost bar is really variable where it used to just max out. Car drives great. Is that gauge really showing intake boost pressure or vaccuum pressure in the wastegate circuit?

Darrington

B5, less the engine oil, filter and cabin filters. So, pretty much a brake and transmission fluid change. Pricey, but didn’t feel like doing it myself.

Paperwork doesn’t show they did any software updates, but the ‘door’ to the OBD2 was closed, which was open when I left it.

Haven’t really had a chance to push to see if any changes. Mine’s a C400, so don’t think I have a boost gauge.

kistiyanpetrov

But before you bring the car to Dealer did you got full boost bar, request Xentry what they updated I assume TCU for sure is updated, so if you hit full boost bar before you bring the car to Dealer it should be something related to TCU update, check also on OBD scanner what max turbo bar hit on S+ on full throttle, I check and I saw i can hit up to 1bar not more.

kistiyanpetrov

So nothing to worry about on your side then

kistiyanpetrov

Some info regarding my ECU and TCU updates, i found that there was recall for both of them

The ECU N3/10 update is about some emissions to heat catalyst on every start up on the car (which I notice that everytime when i start the car even if i drove for 2h and turn it off for 5-10min will idle to 1400RPMS really annoing) - https://mb.oemdtc.com/1096/update-en...lass#more-1096

The TCU N127 update is about - the powertrain control unit may not correspond to the current production specifications. It is possible that the next maintenance interval is displayed to the user as a negative distance reading in the instrument cluster.
https://mb.oemdtc.com/1652/update-po...lass#more-1652

So the TCU update somehow affect my boost to not be full, and still don't have clue what is the problem, i've changed the Transducer valve + teh valve on the vacuum pump the car is better from lower RPM's for sure but still not do full boost

Prodbyjr

So what I'm getting from all of this is you either do the update from MB and sacrifice full boost for no jerky transmission or have full boost and a jerky transmission? I have a 2019 C43 with a jerky transmission and I haven't done the update from MB but I wouldn't want to get this done if it results in not getting full boost and the car not performing at its best. Unless the boost gauge is inaccurate and the car truly is performing at its best AND does not have a jerky transmission anymore? Could this be a possibility? I highly doubt everyone has boost issues and has to replace all sorts of valves and seals after the MB update just to get full boost.

kistiyanpetrov

If i've to decide i would stick with the jerky and to have the performance which i had, because im running the same remap currently and is not produce the power which had before, so I can't really say what is the reason behind the half boost but obviously happen right after the update, my dealer seems are not that smart or idk what to say to them to tell me what could be the issue

Recently I chat with a guy who complain from jerky trans and i told him to take latest update from the dealer and he sent me video that the car still produce full boost and he is very happy for my recommendation, so i would suggest you if you step in the Dealer let them know that the car is doing full boost (to insure yourself and in case something goes wrong to be on their hand) even if have take someone from the Dealer with you just to prove them you got full boost and right after the update go and check the boost gauge if showing correctly

Just bear in mind the car will not feel as it is now because will need adaptation to learn when to shift

Hope i helped you just let me know here or in private if you do the update to see if everything is fine (fingers crossed)

Prodbyjr

That is very true I could show them before and get them to take it for a test drive if needed. I just tested it myself and I confirm before the MB update my c43 performs with full boost. I really hate the jerky transmission even though it doesn't happen all the time but I may have to gamble and get the MB update done.

kistiyanpetrov

also go to someone who makes tunes to make copy of your current ecu/tcu files just in case, i think you might be able to revert back if you have them