Fuse F16

[135i_Life]

I ran a diagnostic on all modules on my 135i to check codes etc a while ago. It showed a code for the AUC sensor, indicating an open condition. I didn't think much of it because that sensor controls vent open/close when AC recirculation is set to auto so it brings in fresh air, but not when the air is contaminated with exhaust fumes etc.

I recently decided I was going to fix that, so I looked up which fuse it was, and accidentally pulled the wrong fuse. I was supposed to pull F15 according to what I found, but I checked F16 instead, and it was blown, not realizing my mistake, I ordered some mini fuses to replace it, since I didn't have any.

I replaced that fuse and thought it was odd when the power and smoothness of my car had improved significantly. How could a fuse that controls an air recirculation have an effect on performance. That's when I realized I had swapped F16 and found that it was connected to the DME. Technical diagram seems to indicate it connected to a DME relay.

There were no codes indicating anything engine related. The car would previously not always be smooth between gears and not accelerate as well from a gear not in the optimal power torque band, now it is smooth and accelerates as expected. I also wager that my fuel economy will likely improve slightly as well as a result. I'm curious what this fuse actually controls.. Additionally, the AUC sensor failure also disappeared..