I've had my 2010 e63 AMG about a year and recently, every time I accelerate hard/launch the car displays "ESC Inoperative" and goes into limp mode. After I turn off the car and wait (variable) length of time, the car will restart and run normally until the next time I punch the gas and it goes back into limp mode. The original owner installed Renntech ECU upgrade and I believe this is contributing/causing the issue. I live in Nebraska and the local Mercedes dealers in Omaha and Lincoln can't figure out how to correct the problem The Tech in Lincoln is Renntech "certified", he reflashed the ECU and thought he corrected the problem....Nope.

Has anyone else experienced this? Is it an issue with Renntech upgrade?

Do You also have a Sprint booster installed? Can the technician take the car back to stock settings and see if the problem goes away?

No Sprint booster on the car. I''ll ask about taking settings back to stock. Funny thing is the techs don't seem to know what they're doing.

The other thing to do is call renntech

I support people that want to time their cars and power to them

But this is exactly what I don't have patience for and am glad to be stock with a measly 577hp/590tq

Question. Did you buy your E63 with the Renntech ECU upgrade already installed ? If so, the dealer should be liable to fix the problem no matter how serious it is. If you didn't buy your E63 with the upgrade, then Renntech needs to fix the problem or provide you a full refund and restore it back to stock ECU condition then have Mercedes fix it if the problem persists.

If you search through the forum, members that encounter limp mode with ECU upgrade are seen as spark plug misfires although I don't know about the ESC being inoperative. Maybe it's worth for the dealer to try and replace the spark plugs ?

Good luck.

Op:

Please read this link

http://www.benzworld.org/forums/w212...sg-before.html

Gas pedal issue. Mention it to your SA. You'll need to replace the gas pedal and rest perimeters. Your tune has nothing to do with it!

People with sprint booster had this same issue and it was a gas pedal issue as well, though their issue resolved with removing the sprintbooster which is installed into the pedal

Thanks for the information. I just ordered a new gas pedal, which I can replace myself. Not sure how to "rest" (assume you meant reset) perimeters though.

Vazha - I replaced the gas pedal and performed multiple 0-60 runs....the problem is fixed! Mercedes techs weren't able to figure this out and I'm not sure what I would have done without your advice. THANK YOU!

Sorry for reviving this dead thread but its the only place where i've found a similar issue to what i'm having. You said replacing your "gas pedal" fixed the limp mode issue? I've got a a 2014 E63S. Just bought it over a month now. Decided to get it tuned, its at a independent shop. The guy there knows his stuff though and works on twin turbo lambos, porsches etc but specializes in mercedes. Before getting the tune he did a obd2 diagnostics and found 3 codes: two cylinders were misfiring and a intercooler pump had failed, so the coolant is not being pumped through the system, just staying stagnant. He said he found the misfire issue and it was a coil pack that went bad, he showed it to me and replaced it. The misfire codes went away and has not come back. He then said I can get the tune but I cant push the car too hard until i get the pump as the engine will run hot quickly. I said ok no problem. I get the tune and driving I give it a couple pulls and then boom limp mode and a error message "Pre-safe functions limited" "Traction off" "lane assist off". I restart the car and everything goes back to normal, now this has happened at least 5 times now and only when I launch hard or accelerate hard. Even with a cool engine. The tuner said he is going to install the pump free (i bought it myself) and see if thats the issue or if it is something else. I believe its something else.. I've heard spark plugs could be it, but I already saw that the previous owner replaced that in 2018. They should be good? and i dont have any codes for misfiring again. But this pedal thing is new to me, do you think this issue can be my pedal as well? why didn't it happen with the stock tune? How does a pedal affect the tune?