"Nice" dealer.... Time to find another one where to take your business with, if you can. You cannot do it yourself, you need a OBD device to connect it to the car for diagnostics to change that I am afraid... Maybe other members have other ideas, that do not require a dealer..... And 60$....
I took my 2016 Prius 4 Touring to the dealer, and they programmed the back-up beeper to beep "only once" for free. I'd call around and find another dealer. Too bad we can't re-program the back-up beeper ourselves like we could with our older model(s). Quite honestly, if if's going to beep, it should be outside for the pedestrians behind us.
The miniVCI has that capability but you'll need a windows XP laptop. Some have gotten it to work on other Windows versions. Caution, do not run miniVCI while connected to the internet as it will 'phone home' and brick. Bob Wilson
See thread below, diy if your comfortable doing it, just a cheap OBD2 reader and carista app, can be done in 5 mins. Any carista users on gen 4? | PriusChat
This could be a clever "dealer test". If they will reprogram it for free, maybe that would be a good dealer to take your service business to? The Carista is a great way to customize a lot of the settings on your car, and it's completely easy to change them back if you want to. My dog always forgets to fasten her seat belt when she is riding shotgun around town (she wears a harness clipped to the seatbelt on the highway), so I used Carista to shut off the beeping from that seat. If I have a human passenger I can set it back in no time.
NO! D*mn it! I bought beeping backup lights on eBay and put one on our 2003 Prius: clearly heard outside the car at the rear muted just right for the cabin Bob Wilson
Just got back from my dealer and had my windows tinted and asked the service person about the back up beeping and he did it for free!!! I guess it depends on who you talk to.