I have had the same battery problems that are still unresolved after Mercedes changing the battery and also turbo lag but I think its just the aweful transmission. If you drive it in manuel mode it goes okay.

 

Same problems here, getting to a stage i think its go to go.

 

Just don't quite floor it if you re in 1st gear piddling around. For start from stop, do a little power braking.

 

I'm in a unique position in that I've had two 2012 MB C250s over the past several months. Also, many of my coworkers drive the same car and we've all complained about the throttle lag that is described in this thread.

Both the C250s that I've had were identically equipped but the throttle response between the two couldn't be more different. The second one doesn't have any lag what so ever and is such a pleasure to drive.

It appears that MB has fixed the issue late in the 2012 model year.

 

If this is true there must be a new ECU flash available.

 

Hi Rob,

Do you have this info from MB or do you think they have changed it ?

If you have it from MB i will contact my dealer...

 

They've changed it, no doubt about it. I believe MB is applying an improved throttle map at the factory.

I've been driving my late year production 2012 C250 for two months and it has been an absolute joy.

Several coworkers of mine have recently replaced their 2012 C250s with 2013s and all have been impressed with the improved drivability.

Hopefully, MB will offer an update to owners of earlier C250s through their local dealerships.

 

That's good news. The new map will hopefully be on dealer Stars.

 

Thanks for the info, i have an early FL 2012 C180CGI so i will ask my dealer about "flash".

Had an C180K 5 speed auto trans and my dealer also flashed this, was a big difference.

 

Great news for earlier C250 owners, and likely not an expensive fix for MB. I bet it's both ecu and tcu remaps.

.

 

Has anyone had this done yet?

 

I'm not, but i have to go for service next month and will ask the dealer about it

 

OP, hope a flash is available. As otherr's said, the sprint booster will reduce built in lag for normal take offs.

The flooring it => redline from slow speed is someting YOU have to adjust for. The TCU is not perfect, and MB loves to do short shiftng to put you at slow speed and low rpm related with too high gear.

You might do a slow floor, of drive in S mode.

.

 

I have tryed the Sprintbooster, loved it on my kompressor , but on the CGI it's a no go for me.
It was way to sensitive....

 

My mistake ... too many replies per 30 minute period. I forgot he had a C250, so I agree ... no sprint booster.

.

 

Can they remap the TCU to not change up so readily?

 

I don't think the first issue is a problem. I have same thing with my 09 C300

 

HI ,

I am facing the same problem (second one) with my C250 CGI 2010 model. My service provider told me to replace Catalytic Converters , as its a common problem with CGI system.

However , i suggest before you change it, try cleaning it with special chemical. and also replace your air filter , if you haven't done it for a while.

Cheers

 

Hi everyone, (C250 CGI 2010)
I havent been able to find a correct thread to post my issue, but I think this one is more relatable.
So I have been having a lot of issues with my C250 CGI 2010, but the current issue has been a headache, The car had a fuel pump problem low pressure with the faulty code P254000, P254009, and P253909 (xentry) but I have been able to drive the car flawless with no issue, in fact I have driven the car for more than 600km, anyway we tried several pump eventually we found one and two faulty code went away, Currently I only have P253909, at this point I drove it for a day, then the acceleration problems started, When I put the car in parking "P" the rpm would flow normal from 0 to 6000rpm with no issue at all and no idle problem or any misfire or rpm shaking, but when I put it D or R the engine rpm never pass 1200rpm If I hold it for too long the rpm would jump to 4000rpm the car has no other faulty code, what we have done so far, we have swapped a working throttle, swapped and reprogrammed engine ECU, I have changed transmission control and transmission oil change still the car wouldn't accelerate, I have also changed Fuel Control Module, and high pressure fuel pump, But still rpm would not rev pas 1500rpm in drive, any suggestion in what to do next,

 

Understand that when a car is in P or N, there is effectively no load on the engine when you rev it. And with a turbo car, you will have very limited boost (if any) with no load. The DTC indicates a fault with the Low Pressure Fuel Sensor, which may impact fuel delivery to the HPFP. When in gear and under load, you're limited to 1200-1500 rpm, which may be a restriction to protect the engine. Too little fuel while under boost can be destructive to the engine. But I would think you would have other codes. Is the P2539 shown as Current, Stored, or Permanent?

You have done a lot of work on fixing this problem, but when you replaced the HPFP, did you also replace the low pressure sensor? Also, I'm confuse about replacing the engine ECU. Was this all done by Mercedes or an independent shop?

 

Okey, so engine control was not programmed with the Car VIN, we had to replaced with the coded one, This was done at independent repair shop, fault code P2539 is current and stored, when in gear if hold the car accelerator for too long, rpm would rise slowly but it takes really long time it could take almost 3-5 minutes, it will gain power, later, its not like its completely stack in 1200rpm, HPFP had no pressure issue it was leaking fuel, so we had to replace it, I need to be sure why there are no other faulty code, Could this be a transmission issue?

 

I did not replace fuel sensor, I only replace rear pressure sensor "on Fuel filter"

 

If I understand you correctly, you have a mismatched ECU in the car. I'm surprised it runs at all.

 

yes it was running without any problems