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      06-14-2011, 05:00 PM   #406
orionredwing
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Drives: 335i Sedan, 135i Coupe
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When running a tune, I was going to say that a strong possibility would be traction induced limp modes. I saw in a follow-up post that you ran with it completely off, so it doesn't apply to you, but since nobody has mentioned this yet, I thought it was great to share and discuss.

Last year, I also triggered limp modes while running 10/10ths (DTC button pressed once), but no problems at 8/10ths. Oil temps were still normal.

After feeding this back to Shiv, he explained that it may be a traction induced limp mode, where the DTC logic was trying to dial boost back to 5psi, but the tune was still trying to hit 11-15psi (or whatever you have it set to).

He gave me a new set of PROcede maps/firmware to try w/ the early stages of his traction control feature, and my low oil temp limp modes went away next track day. I verified that the PROcede dialed boost back to what the ECU wants during traction controlled triggered events, but quickly builds back up to targeted levels once traction is regained, so the net effect is unoticeable (no feeling of being bogged down beyond what traction control was already doing).

Although this possibility doesn't apply to you, since you run w/ traction control OFF, I think it's valuable to share in this thread. We're doing a great job of identifying and discussing all the limp mode inducing causes on the track. I should draw up a fishbone diagram or something For those who don't know what it is, it's a common tool used in problem solving methodologies.

P.S. I bet you had no idea this thread would grow this big. But I guess unlike the other sub-forums on e90post, us track enthusiasts don't feel a need to start new threads for every point of discussion, lol. Otherwise, I may have done so, as this may be worth highlighting in a new thread since it's different from the typical oil and water induced limps we've been focusing on.

Quote:
Originally Posted by PeterM1 View Post
yep, that's why I mentioned that something else is going on, other than oil and water temps.

I was driving at 10/10s when I got the limp modes. Zero limp modes at 8/10s. Oil/water temps below thresholds at 10/10s.
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