[Isaiah5411]

My car is having trouble taking the AA tune. We are now trying a series of tunes ranging from soft to aggressive to see if we can ID the problem, which is the car occasionally going into limp mode. (Note: It never did this before the tune.)

The weird thing is that there appears to be no rhyme of reason as to when it goes into limp mode. With the initial tune, it did it twice within the first 24 hours, both while first starting out in D (auto tranny) from a resting position. It then did it 1-2 times per 24 hours for the next 3 days, usually when cruising at 40-65 mph. It NEVER did it under load. And I have never driven this car as hard as I did during those 5 days...lots of WOT, redlining, shifting down and winding it out. Never once did that kind of stress send it into limp mode.

Note: On the same day we put in the AA tune, we did the 3 stage manifold conversion and the Euro air box Using my original MAF, which is now 8 years old).

So, we took out the tune and replaced it with the stock one. It ran fine and never went into limp mode over a 3 day period. I then took it to BMW and had the software updated, which had never been done since it was born in Oct. 2007. I drove it for two days afterwards then put the tune back in. It went into limp mode three times that day, again never under a heavy load, just as it had done before, and did it twice more before I could change the tune out.

AA sent me three revisions from soft to aggressive. I have been running Revision 1 (softest) for 2 days without issue and am about to go to Revision 2.

Here's the question: Someone mentioned programming the ECU to prevent it from sending the car into limp mode under these circumstances, which appears to be a torque-limiting event due to some conflict between the tune and my car/ECU/Transmission/DSC. It has been suggested to me that the ECU can be programmed to prevent it from creating the kind of error codes (below) that result in limp mode under these circumstances.

Can this be done? If it was happening under load, I wouldn't consider such a Band Aid and would want to get to the root of the issue. But this appears to be a software conflict/glitch between my car and the tune and happens so randomly and under the strangest of circumstances that I wonder whether coding out these faults is the way to go as some have suggested.

Thanks!

Here are the faults it throws during a limp mode event. There are never any fault codes thrown between events, only immediately during/after the limp mode event. (Codes being read by BMWhat Wifi adapter thru iPhone 5s.)


0. Motor Control:
<--------------------------->
Engine / Motor:
- Fault: DME digital motor electronics, internal error: actual torque control
- Code: 002D59
<===========================>
1. ABS / DSC / Brake:
<--------------------------->
Dynamische Stabilitaets Kontrolle / DSC:
- Fault: Engine torque is not adjustable CAN
- Code: 005E19
<===========================>
<===========================>
3. Transmission Control:
<--------------------------->
Transmission / Getriebe GS 19:
- Fault: :K-Can Bus off
- Code: 00CF17 (Note: This code was there before the tune and never clears.)
- Fault: sorry, unknown DTC fault
- Code: 005817

[Billit335]

run your car with the DTC disengaged ? Try it see if it makes a difference. Which is your traction control, and it cuts off your fuel supply momentarily while it senses wheel spin, your car may interpreted that as a fuel issue and go in to limp mode.