Removed seats to clean and now airbag light blinking

Check and redo the plugs Make sure that both ends of the plug seat and car side are well inserted into their plastic members that allow them to fit together male and female and so on sometimes those wires contend to push out while you're pushing them together so make sure you have a connection but generally there's no resetting of nothing If the car was off and you took the seat out did whatever you were doing under there on the floor vacuuming cleaning housekeeping and then when you're ready to put the seat back in you set the seat back in plug up the plug and start the bolts turn the car on it should never know that the seat was gone for an hour or two while you were doing whatever it has no idea It does now because there's a connection that's a miss I would think.

 

You can get the trouble codes from the airbag system using a scan tool if you have one, or this way if you don't:

Blink (a/k/a Flash) Codes – How to. | PriusChat

It makes sense, of course, to go back and recheck the connections you made, but even then it often helps to know what the ECU says isn't right, so you know what you're looking for even if when you recheck it you think it looks ok.