Pete7874

What do you want from me?

How do you explain that the previous poster sees different rpm between E and S when he cruises at 60 mph if according to you they should both be in 7th gear by then?

Isn't it possible that on these newest C-class cars the S mode programming is such that it prevents shifting into 7th gear until much higher speed is achieved?

dol4er

On S, my transmission engages one gear lower than on E because that's what S means. Lower gear means faster response, acceleration and etc. That's my explanation of the way my car behaves on S.

kevink2

Rather than equating all C250's as not reaching 7th gear on a 7 speed ATX, based on 1 person, ALSYLi, I think the focus should be on the exception to the rule. From re-reading his posts, I think his car has a problem, and should be checked out by the dealer as to whether it is making it to 7th in S.

.

sege

On my 2012 C250 the issue is not cruising highway speeds but tootling around town at 40 - 50 kph when it regularly feels like it is a couple of cogs too high and as a result unresponsive. S just makes things jerkyier not better just replaces the problem with another. At my next service I will ask for a reflash.

mac911

kevink2

I agree that it is silly for the car to default to E every time. I was happy my 08 & 09 cars were before they started that. After all, do you have to change the radio, AC, seat position, etc. *every* time you get in the car. No, it stays where you left it. The S transmission button should too. In these lower powered cars, I find driving in C/E not very enjoyable at all.

I would encourage you to write MBUSA and suggest they move future model years back to defaulting in whatever you left it in.

However, I have been told by a local independent that they can change the E/S default. I don't know if it is true, because my cars already stay where I left it. You might try contacting several independents and ask them if they have the computers to make the change (no guarantee it's possible, but I was told it could be done for whatever that is worth).

mikefili

Report with 10,000 miles on car:
Now having lived with this car for such a long time I have one opinion,
Terrible motor!
I am amazed that MB could have done this. Totally unsuitable for the car. You to alter your driving style in order to attemp to stop the jerking starting off from a stop. Every time I get into another non C250 car I need a little while to stop doing the "small motor turbo shuffle"
Just can't wait to get out of this car. Love the car, hate the motor
By the way, MB acknowledged many dissatisfied customer cases open, they settled on an additional amount of $15,000 necessary to take back the 250 and put me in a 350, that was when the car had less than 2500 miles on it. I will wait till the next generation C comes out and will be sure it is a C350
E

mikefili

Well, there now is a recall, yes a recall on the 2012 C250 for this problem. It reprograms the ECU, had my car done last week, it has NOT fixed the problem!
For it to be a recall and not a TSB I can only guess the excessive lag must now be recognized as a safety issue.

MDMercedesGuy

Where have you determined that this recall (that I was the first one to know about/post about/have performed to my car) is to fix lag? Did your dealer actually give you documentation stating as such?

I've emailed my service advisor to see if I can get a copy of the actual MB bulletin.

The lag is a drivability issue for some, but it is not a safety issue. I've said it before and I have said it again: If you put yourself and your vehicle in a position where the lag is the difference between an accident or not, the fault is not with the vehicle.

xaran

Being a newer C 250 owner I posted about the "lag' in the first week I had the car. It was so bad IMO merging on a freeway or trying to pass there was a 1-2 second delay after pressing the accelerator. But my car was a CPO loaner and had 5700 miles on it when I got it so i think it was "lazy" based on the previous drivers input.

I did the Throttle reset as well as the battery disconnect for 20 minutes and it did greatly help the over all driveabilty. But now that I have driven about 5000 miles in the car with it almost always in "S" mode and driving it aggressively a lot of the time it seems to have "learned/adapted" to my driving style it is a much better driving car and I dont have the 1-2 second lag as before.

Im taking it in for the "B" service this week and the Service Advisor said they would also do the ECM reprogram that is out. Im hoping that that will also help a little more

MDMercedesGuy

Heard back from my SA, who copy/pasted the bulletin into the email.

Per the bulletin distributed to dealers:


Nothing about lag was noted.

fireline43

I'm at almost 6k miles on my 2013 c250. I love it. I've hit the hesitation a couple times, but I'm not a risky driver, so they didn't end me in an unsafe spot. Once I learned how to use the pedal, I actually think the car is pretty fun and spunky.

sege

You are right about getting used to the Pedal especially as it is the old style floor mounted rather than the modern "hanging" type.

strangebrew

I know this is an old thread I am resurrecting, but I too had some serious lag issues. Got a 2013 sport plus as a loaner once and was astounded how much peppier it felt. My C250 could definitely get up and go if you gave it time but it seemed to dig itself a hole it couldn't get out of especially around town accelerating out of right hand turns. Tonight I just disconnected the battery, waited 10 min, and then drove pretty vigorously. Initially, there was some jerkiness in response but it was definitely quicker regardless. Drove it for about 30 more miles and it felt great. Very pleased that the battery disconnect seemed to work for me. I suggest anyone with problems like mine give it a try.

MDMercedesGuy

See my post in the other thread. Do the throttle reset steps, don't constantly disconnect the battery. You're resetting a lot of other unneeded stuff as well as creating risk of damaging components with unnecessary battery disconnect/reconnects.

alsyli

MDMercedesGuy, do you re=post? You're a prolific enough poster that I can't easily remember/find the thread (I'm also kind of lazy).

MDMercedesGuy

Haha... certainly.



I personally do it every couple of weeks - and usually when I get home at night, so it sits overnight afterwards. It shouldn't matter though.

alsyli

Gracias. =) Question: does this solve the prob w/ the transmission that was noted in the TSB?