Quote:
Originally Posted by fuddman
On my 2013 M3, on different starts, I get different numbers of warnings on the dashboard - sometimes several warning lights, sometimes two, sometimes 1 and sometimes none. The one that always seems to be there is the SES light. The car then posts the message "Increased emissions!" With an exclamation mark, no less - like you bad, bad boy, you're screwing up mother earth.
In any case, this got me to thinking. What does "increased emissions" mean? To me it means there exists some kind of fixed emissions baseline in the car somewhere. In addition, something is constantly calculating the emissions generated by my car and going out the exhaust.
Then, the two are constantly compared somewhere in the car. That is, my generated emissions are compared to the baseline emission and if, for example, a ratio exceeds a certain amount, the SES light goes on.
Could it be that if that emissions ratio exceeds another predetermined value the car will be thrown into limp mode?
What I'm thinking is that perhaps there is nothing really wrong with the gears in the throttle valve actuator. And the car could go on indefinitely. Except that someone has determined you are exceeding what they believe is the acceptable amount of emissions going out your back end. Therefore you are assigned the limp mode.
In other words, you're not going into the limp mode because of a gear problem. You're going into the limp mode because you are exceeding an emissions standard.
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No, the SES doesn't 'cause' the car to go into limp mode. Sounds just like bad T.A(s) to me. The Christmas Tree light dash at start-up is typical prior to total T.A. failure(s). You may have only one T.A. going bad causing a lack of throttle body synchronization between the two banks. The DME/ECU checks for this synchronization (calibration) parameter upon start-up. If the test is failed, then limp mode typically ensues. Read the fault codes to know for sure. Regarding the SES dash light; here's the official thread on the topic which began in 2009 and has almost a quarter million views.
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SERVICE ENGINE SOON THREAD:
https://www.m3post.com/forums/showthread.php?t=310475