Sienna power windows fail after battery change

Dude, that SUCKS! Replacing the battery shouldn't kill your windows. Is the error code specific to all the windows or just one? Maybe a fuse blew when you were swapping the battery? Check the fuse box first, it's the easiest thing to check!

Good call on the fuses! I checked, and they all seem fine. The error code is for all the windows, so it seems like a system-wide thing. By window regulator, does the error refer to the motor mechanism that moves the window, or something else? What could be wrong with the regulator initialization?

Yeah, window regulator refers to the motor and all that jazz. If it's all the windows, and fuses are good, sounds like the system didn't like the battery change. Honestly, you might need a proper scan tool to reset the window system, or take it to a workshop. Sounds beyond a simple fix.

Thanks for the reality check! I was hoping to avoid the workshop, but it looks like I'm out of my depth. Turns out the window regulator initialization had to be performed using a professional diagnostic tool. Cost me 290€, but at least I can roll down my windows again! I appreciate the help!