Yea this seems to be happening alot lately. happened to the E90 boys over at E90post.com but that was basically due to their higher boost levels. i would do what "0bD" said and remove the mods. i would try the dealer but they'll know everything you did with it mod wise. since the 535i uses the same engine as the 335i, the DME stores all information including boost pressure. it's so sentive, that it detects if you changed a bulb. so when the techs pull the car on the Diagnostics reader, it's gonna show abnormalities that BMW doesn't normally see. which leads to their investigation of vehicle tampering. best way is to remove mods, and see where that goes after a reset. if that doesn't work carry it by the dealer. hopefully you'll get away with it and not a pay a dime.

 

i know the e60 has a lil over 8 lbs of boost, how much more does that e90 have?

 

Limp mode is not uncommon at all. Like previous posts have said the E90/E92 guys have been experiencing this, especially on modded 335i's.

It also isn't uncommon to happen on unmodded or stock 335i's.

During the Motor Trend G37s vs. 335i comparo. The 335i went into limp mode on their test track.

 

I read that same article. I've read that the reason was that the tested 335i oil overheated because the initial production run of 335i's did not have the oil cooler.

 

Though the DME is very sensitive as you describe, I think that the SSTT is engineered to not activate these types of codes since it keeps boost within production tolerances and tapers boost as RPM's increase or as it senses an overboost condition. I agree that the DME will log the code, but what its cause(s) is/are will be pared down after I remove the mods. "Hopefully" the code will reappear after I remove the mods. Because of its unpredictability, I have not been able to identify what conditions (driving, environmental, mods, etc.) create the code.

Because the reduced power has been activated during normal driving conditions, oddly enough, not during spirited driving, I'm leaning toward an existing condition before mods. The fact that the mode was activated shortly after I installed the SSTT and changed to race gas may be a coincidence since I installed the mods 2 weeks after purchasing the car as a CPO car. There have been times that 1-2 weeks have passed without a code.

This is a good one for the tech heads in our readership!!

 

Recent "limp mode" thread on E90post.com.

The owner experience a limp mode while entering a freeway. His car is completely stock.

http://www.e90post.com/forums/showthread.p...light=limp+mode

Great info in post #8.