N00b with the dreaded "self-level susp inactive" warning...

[Ragnarok]

Hello all. Somewhat unexpectedly I got myself a 2003 E53 4.4i last fall. I will spare the details of that for the introduction thread. I have since been lurking on this forum, observing, listening, searching, and learning. Unfortunately I have finally reached a point where I must ask a question, and it is a subject that has been beat to death. My apologies. So here we go:


Last fall, I started getting the "self-level susp inactive" warning intermittently. Everything worked fine otherwise, and it would come and go, and I was busy with life and fixing other things, so I ignored it. Sometimes it would stay off for a week or two at a time. Then one day it came on and stayed on. Over the winter, the airbags slowly leaked down. This took months. I have now been riding on the bump stops for the past few weeks as I troubleshoot. The system is silent. Nothing has worked so far.



I believe I have tried all the easy/cheap things. I have unhooked the battery to try to reset the system. All 3 fuses are good. A visual inspection of all the components shows everything in good shape, clean, and in good repair. Earlier tonight I replaced both ride height sensors (one of them was original), no change. The air compressor is silent at all times.



So, am I missing anything? Is there something I need to do to reset the system, if replacing the ride height sensors solved the issue? I am at the point of just replacing the bags with springs for $120 and calling it a day. Any fix that is more expensive than that will not be done, for multiple reasons. Are there any more inexpensive things to check? Have I missed something silly? Any thoughts or pointers would be deeply appreciated. Thank you.