blizzard12

My transmission is super annoying and it's not the rough shifting issue described in other posts. Shifting is smooth, but under normal acceleration in 1st gear it revs up to ~3500 rpm before shifting into 2nd then milliseconds later into 3rd. From the 3rd up everything is normal.
Below is an attempt at a visual representation of the gear-acceleration of what it should be (1st line) vs. what it actually is (2nd line):

-----1-----/-----2-----/-----3-----/-----4-----/-----5-----...
----------1--------/-2-/-----3-----/-----4-----/-----5-----...
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I've read in one of the posts that it is possible to have the transmission re-programmed but it takes 2 service techs + a laptop + a long drive.
Does anyone have any information on how to request this without the dealer saying "there's no such thing" or denying that such procedure can be performed at all? I need some proof that it can be done/has been performed before.
Also, I'm pretty sure if I ask whether there's a software update for my transmission the dealer will say "sorry, no".

I've had it reset (not re-programmed) by the dealer but the shifting pattern didn't change.
This is a 2017 C300 with the 7G transmission.

As a side note: every time I move off at a green light the high rpm sounds like I'm trying to race the car next to me while I'm not. It is super annoying.
I've found that if I lift off the acceleration before I reach 2500 rpm in first gear then it shifts into 2nd and things get normal from there on. However, that's not a viable solution as it sort of jerks the car.
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ManiacGT

Yes this is normal and intended operating/shift mapping for this car as the mapping is economy focussed.

I tend to use individual mode, with the transmission in sport setting to avoid this as I'd rather have a 'normal' transmission response than the rather weird comfort mode map.

I could live with this if they could solve the jerky transmission, which oddly this last few days has been ok and only the first 1 or 2 shifts after the car starts being snatchy.

Still a darn poor 'box in my opinion, lord knows who signed this off.

blizzard12

I picked up a 2017 GLC on the weekend for my wife. It has the 9G transmission and it does not show the above symptoms. Much better shift mapping!

ManiacGT

yes because it's an entirely different transmission.

blizzard12

Thank goodness!
BTW I drove a demo (2017 C300) and the shifting pattern (1-2-3) was better than mine. Almost perfect I can say...

ManiacGT

wonderful... how does that help the OP though?

Gungaslow

Time to get a 2017?

blizzard12

It proves that it CAN be done the right way.

blizzard12

It is a 2017. Both the demo and mine are 2017 with 7G yet their transmisaions work slightly different. I guess it's software...

removedCFGaccount

You should deal with MB USA. These things don't produce error codes and you need a competent tech, with prior experience.

Stefan-c300

I have a 2017 c300 in Canada. I have the exact same symptoms as you in comfort mode. The dealer told me this is normal and it's for fuel saving or something. I find that driving in sport mode but gentler on the pedal is perfect transmission shifts. Then in sport + mode if I'm pressing 3/4 on the pedal, it goes 1st gear to 5krpm, then 2nd followed by third quick. Full throttle no issues.

In comfort mode you have to drive slower than a corolla for 1st to shift at 2,5k rpm into 2nd. So annoying. I would love to hear a success story on fixing this, it's one of my biggest gripes about the car.

removedCFGaccount

Call the service manager at Thornhill, a company store. I'll bet he cures it.

Stefan-c300

Thanks for the suggestion, it's not too far from me, I'll go after work tomorrow talk in person. Will report back when I'm done.

Edit: it was Markham Mercedes that told me it was normal and nothing to be done about it.

removedCFGaccount

I don't know Markham from diddly, but Thornhill helped me here in the U,S. When I ran out of clowns. Deal only with the service manager or higher, not lower. Even Barnum & Bailey ran out of clowns....

blizzard12

I guess CFG is talking about a different Thornhill somewhere in the U.S. than the one we know in the GTA, Canada.
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removedCFGaccount

Nope, same one: only dealer in North America that listened to its customers and fixed a similar problem with another model, but same transmission.

I was at my wits end in the U.S. and read about their success. I was told by the SA that as a company store, a merc was merc.

Thornhill Canada, that's the one.

removedCFGaccount

I think the guy's name is Dominic, but it has been a few months-great dealership.

blizzard12

Great! Thanks fir the info! I'll pay them a visit.

removedCFGaccount

Funny, really: when I told these guys I was in the U.S., they promptly asked how they could help. Imagine that....

blizzard12

I just got off the phone with them. The SM is leaving for the day so I won't be able to see him before tomorrow.
Anyway, they told me his name was Ronnie. Do you think he's the same person who took care of your car?

removedCFGaccount

Oriental surname? If so, that's the dude.

blizzard12

Yes, like 3 letters.

removedCFGaccount

https://www.mercedes-benz-thornhill.ca/about-us/staff/

I dealt with Ronnie and Dominic as shown above: both top drawer guys.

Dominic is the guy who said that to them, a merc is a merc. Smart.

removedCFGaccount

If these guys can't diagnose and fix it, I suspect you are well and truly hosed.

jlr82

My 2014 W204 shifts exactly the same way. The programming has been this way for a while. It's better in any mode other than comfort. I'm going to have the dealer update my software to see if it helps any, but since you guys are reporting the same pattern on the W205 my guess is it's by design and not something that will be "fixed".