Awhile back we put new tires on our 2008 Toyota Prius. When we did this, we had the alignment done as well. Ever since it came out of the tire shop, it seemed like at random the traction control light would come on and the car would make a very loud “beep beep beep” until you got below 30mph.
I was getting so frustrated with this that I almost traded the car in. We didn’t buy cheap-shit tires, and the place that installed the tires gave me the “WTF do you want me to do about it look” when I went back in to ask them about it. I checked every single detail on the tires. I tried different air pressures. I rotated the tires every which way. Then, by dumb luck I stumbled on an article on alignment and suspension specs over at BrakeandFrontEnd.
Long story short, if you get your Prius aligned and it goes on a beeping rampage, the shop didn’t reset the sensors, so just reboot your car by disconnecting the black (ground) wire from the battery and walk away for a few minutes. Come back and reconnect the wire and no more maddening beeping!
Yeah, the “reboot” causes your car to forget the current sensor data and reload it fresh from the newly aligned sensors. I really hope this helps someone – a Prius acting like the bus from Little Miss Sunshine really sucks.