How can I tell if my 2002 Prius has Side Air Bags?

One possible way is to look under the seats, to see what wiring is leading up to them. You would expect to see more wiring where the seat has a side airbag installed. Usually the SRS wiring will have bright plastic armor around the wiring, perhaps yellow in color or some other distinctive color.

If the seats do not have side airbags, then the driver's side seat won't have any wiring while the passenger's side seat will have only one wiring harness connector for the pressure switch that shows if the seat is occupied.

 

You are right, the seat belt buckle on both sides also will have a switch that requires a wiring harness.

 

Actually its quite simple, look at the side of the seat where the recliner is on either driver or passenger. It should have a colour matched grey sticker that says SUPPLEMENTAL RESTRAINT SYSTEM. If you do not see it on either seat, you do not have side airbags. I know because my Prius was one of those few that did! Lucky me!

 

Note the OP's car has seat covers. He was looking for a way to determine presence or absence of the side airbags without having to remove those covers.

 

Actually the sticker that says "SRS Side Airbag" can be found right where I have the arrow. It is just beside the handle that reclines the seat, right on that plastic panel. There is nothing to remove. This particular picture does not have the sticker, but I assure you, my car does. I will take a picture if I can later for you.

 

Yes, I'd like to see that. I recall that my 2001 which had side air bags had a cloth label tag sewn into the seam on the seat back, facing the doorway.