harryd840

Hi,

I bought a new 2014 C300 4Matic ( my first car ever) about 3 months ago. Since last month I am noticing a strange behavior. When I am driving uphill and let's say halfway through the climb I feel a sudden jolt/jerk when there is downshifting of gears and then it picks up speed. I think I maintain a speek of 40-50 km/h while climbing.
Its an automatic transmission and I think it should be silky smooth and should not jerk while shifting regardless of the road gradient.

Can anyone please advice if this is a TCU software problem or a normal behavior?
I am planning to take the car to the dealer this week but wanted to get more info before I do so that I am not fooled into thinking it's a normal behavior.

Any help is much appreciated.

Cheers...

Pete7874

Does not sound like normal behavior. I had a '14 C300 4matic rental a few days ago, and didn't notice any jerky shifting behavior.

goldenears

I suffered with exactly the same problem on my 2009 C250 for over a year, also jerked when going from D to R sometimes.

Took it over the the main dealer, they looked at it free of charge and advised it had been loaded with the wrong software version! 10 mins later and the car was back with me, now it feels like new, wish I had gone back sooner.

Might be different with yours as its brand new.

tonyteetime

Take it back to the dealer and have it checked out. Auto shift should be smoth and not jerky.

harryd840

Thanks guys, I have an appointment with the dealer on Tuesday...hope they will resolve it.

Btw does anyone have squeaking breaks problem when braking at low speeds downhill...specially when going into an basement garage?

Last month when I took it to the dealer ...they said all C class have this problem and they can't do anything about it....what a shame!

vsix

Some debrese or rust cause squeeking breaks as well as if the pads ( area where the breakcylinder presses on the pads ) havent been greased properly.

Screw what this guy told you....either its the missing grease or you need a different set of brakediscs and pads.

The aftermarket offers brake discs and pads, wich eliminate what you described!

First off go to, step off from visiting a dealer...just find another open brand shop and tell them about your squeeky breaks.

Good Luck!

andp409

I have had my 2014 C300 back to the dealer 3 times for this issue. They have re-flashed the software and changed the shifting solenoid assembly with no results. On the third visit, they had a transmission engineer from MB in NJ there to look at my car as well as another with the same issue. The problem is in the programming of the transmission shifting timing and not a physical issue with the transmission. The main problem is when it shifts from 5th to 3rd. I have been waiting about three weeks so far for the update. I will post if and when they fix the issue. The engineer assured me that driving the car would not cause damage to the transmission.

vsix

This engineer asured you that if your guarantee is up youll gonna have a money pit...
Of course a jerky transmission will cause alot of premature wear, on all kind of parts regarding the driveline, so dont believe such idiotic statement.

If the dealer isnt able to program the car to shift properly, switch to another car, because not all cars have this propblem, dont get fooled!
This car acts up...change it, file an complaint and youll see ...the dealer takes the car back and you are getting another one.

Glyn M Ruck

Kicking down automatically while climbing a hill is absolutely normal when certain programming parameters have been reached. But the kickdown must be smooth.

Tell the dealer to check all adaptions, lock up pressures etc of every clutch pack in the transmission etc. with a Star. If anything is out of range they have a problem

It could be anything from software to a bad valve body, broken solenoid spring etc.

If they can't get it to behave normally then make them fit a new transmission.

mikepottier

I am having the same problem. Brought into the dealership and they checked software. They were not able to repeat the issue. However, it happens so frequently when down shifting its starting to really worry me. Suggestions? I really believe its happening between gears 2-4.

tonyteetime

Don't let the dealer off the hook. Have the tech drive with you and you can recreate the problem so they see. If it make noise during the jerky shift , then try to record that sound , and let them hear it.

Vlad-II

Congrats on the New Car Mike,

But yeah like the others have said, you have to get them to check this issue because if you don't the problem will get worse and they will make you pay a ton of money if it gets damaged because they will say its physical damage and it won't be covered by the warranty.


They will find a way to pin it on you that's how these stealerships are. If anything try to get another opinion from another dealer. If the car hasn't been doing this before in the past and its doing it now its not normal. You can always call Mercedes Benz directly as well and tell them the issue you're having if you want to escalate the issue to a higher level that's what I'd do.


But don't continue driving the car with that problem because its only going to do more damage to the vehicle in the long run.

mikepottier

Any update from the dealership on the flash progamming? I am having exact same problem and have to resolve what the issue is for my dealership because they don't seem willing to look deep enough into the issue.

spyked

I wonder why 2014 models are having the issue. What changed from 2013 C300 to 2014? Nothing for U.S. market cars from what I can tell.

At least if you have a service record of the complaint, you are somewhat covered. A history of the complaint will be in the system, even if they can't duplicate it.

Vlad-II

The only two noticeable changes between the two model years are the Black Grille for the Sport Sedan and the Wiper Blades. Everything else at least from what I read has remained the same.

linkfosta

I have the same problem with my 2013 c300 4 matic. I had jerking issue between 40 to 60. it's not very noticeable when it's warmed up, but specially during the cold weather you can feel the jerk quite clearly. I took it back 2 times to the dealer they had not fix the issue. :-(

harryd840

Guys,

Here is the update.

Took to the first dealer 2 weeks ago. They kept the car for half a day and in the end told me that the jerking problem could not be reproduced. I had told them to drive uphill...which I am sure they did not. They said software was up to date,
valve body was fine, no transmission oil leak etc etc.
Told me to keep driving and see if it happens again. BS!

But they cleaned the brake rotors and pad and re-aligned them and now no more squeaking sound while braking at low speeds downhill.

Last week I went to the dealer where I got this car...100KMs away.
Went on a test drive with dealership owner. We drove around for an hour on hilly roads ( luckily they are located in the mountain town). I made it occur 2-3 times, then the owner drove and it appeared while he was driving. He narrowed down the jerk with downshifting from 3 to 2.
But then he said car has too little mileage and is still breaking-in. Advised me to drive in sports mode instead. I did not agree.
Then he said to wait till the mileage is around 6k and then bring it back in for gear box re-programming if the issue still persists.

Atleast he acknowledged that the issue exists. Will wait till 6k and then take her in. Let's see what happens then. Else will call MB and ask them to take the car back if it is not fixed.

tonyteetime

Harry,

Does this happen in only economy mode or both sport and eco ? I'm just curious on why the dealership owner advised to drive in sport mode.

harryd840

It happens mostly in eco mode..could not observe it so far in sports mode.

Huz-Z

My wife and I are having this very same problem with our 2014 c300 4matic. The dealer did the software update and now the transmission seems just as bad.

Surely others have encountered and know the fix?

uhnwmb

I have a 2010 C300 4Matic and suffered through the jerky shifting for three years. I thought it was normal. When I finally brought up with the service advisor when I was in for my annual service, he advised there was a software update. After the update, I have not had a problem with the shifting since.

Huz-Z

The software update didn't help my 2014.

rossono308

I have the same issue. Predominantly during the 3-4 upshift and 4-3 downshift. It can also occur in the 5-3 downshift. My 2011 non-4Matic had none of these issues. I also had an issue with a severe shuddering when cornering. This, I was told was normal for the 4Matic transfer case and their solution, from a tech bulletin, was to drive the car in alternating forward and reverse figure eights! Did work though I'm not sure how cornering affected the transfer case. My thought was limited slip clutches. I've informed my dealer of the transmission problem through their service follow up survey. I have not had a reply yet.

rev-director

My wife is also having transmission issues with a 2014 C300. Our problem is very hard downshifts at low speed, usually around 30 to 40 KPH and usually under light acceleration. The car has been to the dealer twice and both times they have updated the software and say they can find nothing wrong with the car. I filed a complaint with MB corporate office today and the car is going back to the dealer on Thursday. We bought this car new and are certainly regretting that decision.

Huz-Z

That sounds identical to the problem we are having with our car. The local dealer has tried to fix this for us, quite valiantly I admit, but with no success. In fact, the dealer has been really great. Mercedes at the corporate level however, seems to be trying to avoid responsibility. Certainly, their engineers should be able to determine with 100% certainty the root cause and provide a solution that will work. But so far, they are highly deficient in that respect.