I had a car problem recently--the automatic transmission seemed to be stuck in second gear.
I took it to the mechanic, and he called to tell me that it was a design feature. When the transmission detects that something is seriously wrong, it locks itself into second gear so you can get off the highway, make it to a repair shop, or otherwise recover from the situation without danger.
Something troubled me, though, after I got off the phone.
It took me a minute, but I finally figured it out:
My transmission had booted into Safe Mode.