Originally Posted by Protagonist
When you manually pushed it in, you may have stripped out a gear in the mechanism. You may be able to remove the step for troubleshooting and/or repair by crawling underneath and unbolting it, and then checking it out at a workbench.
As for what caused the problem in the first place, I cannot say. I don't recall having a problem like that. In fact, every time the alarm came on, it was because of the awning, not the step (the two mechanisms share an alarm), though it took me a while to figure that out.
In future, remember that the step doesn't stick out any farther than your passenger-side mirror, and you can drive around with the step extended, as long as you don't plan to parallel park where you could scrape it on a curb. All you have to do is crank up the music until you can't hear the beep. That's not a fix, but it's probably better than breaking the step to shut off the alarm just so you can hit the road.
Protag - you have advised me before and I trust your guidance. My step is stuck in on my 2013 AI. I just visited my local MB dealer for another wheel speed sensor (my fourth) but they said the step was an AS add so they would not deal with it. I asked Chris B at JC but he replied they would have to "look at it". I have a service appointment there in the fall, but would like to get the step operating if it is an easy fix. It is getting power as I can hear the motor whirring.