strangebrew

Today I was making a left turn at a stop light in S mode. Gave it some gas (was trying to have fun but nothing absurd) and suddenly midway through the turn my car lost basically ALL power and revved up pretty high. The car barely made it to 35 mph. I quickly pulled over into a parking lot and turned it off and back on. That seemed to fix the power issue, but the check engine light came on. I drove it again a few hours later and lo and behold the light went away.

I tried reading up about the issue and it seems some people think its an ECU issue or a cylinder misfire. I read a couple of horror stories about this and hope it doesn't go down that road. In the meantime I am going to pray my car doesn't lose power at freeway speeds. Might have to take it in again sometime this week.

Has this happened to anyone else or do you guys have any advice?

Cleanbenz

Sounds like a over boost/ limp mode situation. Sometimes just cycling the ignition takes care of it and sometimes it won't. I'd go get the codes checked and cleared.

strangebrew

Yeah I saw people referring to it as "limp mode" lol. Maybe a software update is available or something. So do you think this is the car protecting itself from high RPMs or could it be a sign of a bigger problem?

Cleanbenz

It could be a number of things such as a boost leak, or bad n75 valve. Overboost can happen when you stomp the throttle and the ECU is requesting an unsafe amount of boost which makes the car think there's a problem because the boost is more than it thinks the car should have so it puts it into limp mode to keep from sending too much boost to the motor. Could also be a loose turbo inlet hose or intercooler piping could have popped off. All will make the car go into limp mode. It's probably something small and easy to fix at home but the problem is finding it. Check all hose connection that have to do with taking air into the turbo/motor.

Glyn M Ruck

It must be under warranty. Get it on to a dealer Star soonest. I'm sure it's minor as CB says.

Tarek307

Very nice of the OP to never update or give us the solution to what happened!!!



i'm having this same issue, wonder if it has to do the burger tuning tune, i only have it at 60% just like it came...maybe i'll take it out & see what happens.

sometimes when i accelerate hard it happens & its as if the car can't get gas or something, turn the car off then back on and its fine

xaran

It says on the Burger site that this may happen on some cars and if it dies to lower it by increments of 10% until it subsides

Makross

happened to me before with the JB+ Tune.

strangebrew

Ah my bad guys. They ran the diagnostics and the dealer told me it was likely I just starved the engine of gas for a minute and caused it to throw a code. I had about a 1/4 tank and the left turn coupled with near-red line RPMs were a bad combo. No permanent damage done. Unfortunately the diagnostics also showed the dealer that I stepped on it pretty hard lol.

Haven't had the problem since. Hope this helps you all

chuang

Same "lost power" issue happened to my wife's 2012 C250 about a year ago, went to dealership and they didn't find anything. The same issue is happening again recently for many times (only has 12,000 miles on the car). Car is in dealer's garage now and the service adviser mentioned that there is a "software update" for this car and that might help. Does anyone have any information about this software update? I checked with the recall and TSB on automd.com but didn't find anything? Thanks!

strangebrew

I do not have the JB+ tune but from what I read I think it was an overboost issue. Just too many RPMs/boost for the engine to handle so it goes into limp mode to protect itself. Some of the JB+ tune users have it happen to their cars quite regularly and kind of shrug it off. It has not occurred in my c250 since the initial post. The dealer has never been able to find an ECU or TCU software update for me the few times I have asked them.

Chuang, did your wife's car have some turbo lag/responsiveness issues? Mine definitely did and I am speculating here...my car had a few hundred miles on it when I bought it and also my commute is very slow to work. It probably didnt help that the engine and throttle learned to drive like a grandma. After seeing a lot of posts on here, tonight I disconnected my negative battery terminal, waited 10 min, and then reconnected and drove like a bat out of hell. That seemed to cure a lot of the lag and it drives much better. My only "limp mode" incident happened when I really stepped on it, and maybe my car (being used to the slow traffic and slow throttle/ecu etc) just couldn't handle it and went limp.

chuang

Hi strangebrew, thanks for your comment. I think that make sense.
In my case, the dealer did updated the software and after that, the lost power did go away. However, during those two days, the dealer gave us a 2014 loaner car (also C250 that only has around 3000 miles on it), and wow it drives like a totally different car!! It's so peppy and accelerate so good when compare to my wife's C250! As my wife also has a slow commute to work (95% city driving) so that might have explained it..

Anyway, right now we are not experiencing the "lost power" issue any more, but the car still drive much less peppy then that loaner car, and they are supposed to have the same type of engine... I might try to disconnect the battery to try out your tip. By the way do I need to know some sort of "radio code" after I reconnect the battery? Just curious. thanks!

Carlos.33193

Happens to me when im low on gas and gun it through a turn from a stop.

MDMercedesGuy

You don't have to disconnect the battery, and for the sake of all of your other electronics shouldn't be doing it that often.

Do this:

1. Turn the ignition key to the run (not start) position.

2. Press the gas pedal to the floor and hold for five seconds.

3. Turn the key to the "off" position (don't remove the key), then release the gas pedal after five seconds. Do not open the door, do not leave the car.

4. Wait at least two minutes for ECU to reset. Restart and drive.

strangebrew

Thanks MDMercedesGuy, I will give that a try too. Have only done the battery disconnect once, so hopefully no damage done lol

sophie14

Omgg this happened to me a month after i bought my 2014 c class... I was in the fwy, heavy traffic so i stopped. My car started moving back and forth, i thought there was an earthquake or something then as i look forward to drive i press on the gas pedal and the car is off. All the lights in the dash go on and the car while in drive turns completely off. So im in the middle of rush hour stuck in the lane while everyone passes me by. I called roadside assistance but finally my car started back up nd drove off. Took it in nd they found nothing. Nothing came up on the computer at all..A month later mbusa Accused me of buyers remorse lol i couldnt believe it. Im scared its gona happen again

2012c350

My car (2012 C350) was in for an inspection around the time yours was. Not sure if it was the same software update but I was told I needed one too because the amount of ethanol in gas was making the engine run too hot...so supposedly that's what my sw upgrade was for.

RascoeP

I have a 2014 C250. I leased it back in November of 2013. The vehicle is driven about 100 miles a day. I didn't have any problem with the vehicle for the longest time but a few months ago while on the freeway traveling 70 miles per hour the check engine light came on and the car started shaking when trying to accelerate. I got the car to the dealer and it was turned off. Once restarted the car ran fine and the light was off. The dealer said that the code wasn't stored and they cant find anything wrong. Since then i have expierenced itermittant power loss. My spouse and brother have also expirenced it and during these power losses it almost caused several accidents. The car has been back at the dealer several times. The dealer will keep the car for a week then giveit back saying they cant reproduce the issue. I have been in contact with MB corporate but they also wont help. I have also found several complaints about this on the NHTSA website.

To date the car is back in the shop and has been there for a week. I have called everyday but have been told the same thing.

wdurst75

Ive experienced this similar issue as well. .I have a 13' C250 Sport and first experienced the power loss/check engine light coming on about a month ago. I was leaving a store parking lot turning right onto the street...I dont recall how much gas I had but I doubt it was less than 1/4 of a tank...usually fill up around 1/2-1/4 tank...I accelerated pretty hard but not all the way down... the car lost power so I pulled over as soon as I could and restarted it but it took me restarting a another time to clear the warning light. This past weekend I was driving up to Chattanooga,TN from Birmingham,AL ...I had been driving for about an hour on the interstate 70-90 mph on average...and I accelerated but nothing too extreme about as much as you would to quickly speed up 10-15mph and the car went into the "limp mode" ...I was able to pull off the road and restarted the car...that fixed it... then later on it happened again at similar speeds on the interstate... luckily there was an exit so I pulled off ...restarted the car once and that cleared the check engine light and the car seemed fine.. its really odd and worries me ...especially after reading everyone's posts about this issue. Planning on taking it in to at least talk with MB about it,but it seems from everyone's posts here they know about it but don't really care. Which really sucks.

RascoeP

You are absolutely corret. Mercedes does not care and will not aknowledge the issue. I have been dealing with them since august 24th when i reported the issue to them. They say that the dealer cant reproduce the issue and the vehicle is performing as designed. But they also wont admit that the vehicle is safe to drive. This whole issue has completely turned me away from Mercedes Benz. I will NEVER own another one.

wdurst75

After the issue happened to me I tried replicating the issue myself...and nothing I did would cause it to happen... so I can see how they're unable to replicate the problem...but just reading all of the posts about it on MB World it seems to me this is MOST DEFINITELY a problem....whether they can replicate it or not doesn't seem of any consequence to me. I feel like you RascoeP if this is something they are going to continually ignore and not attempt to find a resolution I will not be buying or recommending a C250 to anyone again. These types of issues which directly affect a drivers safety should be looked into with their utmost urgency!

Carsy

I hope something is done before it takes a fatality to get things started.

http://www.gizmodo.com.au/2013/06/vo...-in-australia/

yacoub.alyacoub

I got the same problem only after installing the Kleemann Downpipe the car is better now when it comes to driving waaay much smother but sometimes when i floor it i just lose all the power

gtu

Hey guys,
I have exactly the same issue with the car. Did you figure out any solution? The car has been to the dealership 3 times already but the issue keeps coming back. They changed the fuel pump, updated the software and few other things but nothing worked so far. It just keeps reoccurring after a few days of driving it.

michail71

When it happened to me the just said it was a software issue and they flashed the ECU. Make sure they check for software updates.