I was able to turn off that annoying back up beeping on my 2008 Prius by the old hold-down-the-odo-button-while-powering-up trick, but I can't seem to get the same result on my 2020 prime by using the "trip" button. Any info? The back up beep is really terrible. Especially when I'm pulling out of the garage and all the parking helper beeps are going off. It's so many alarms going off at once that none of them mean anything! Thanks!
Since Gen 3, it’s been a dealer visit to turn the beep off. And it’s not off, but just a single beep.
It’s changeable (to a single beep) via OBD2. Carista is an app and includes a OBD2 dongle and can be purchased on Amazon. It’s not free but you get a free trial with purchase which is long enough to do tons of customizations. There are free software apps but you’ll still need the dongle if you don’t have one. Many dealers will make after sale customizations for free if you ask politely. Your mileage may vary. J
There are also free apps that will disable the beep, but you'll need an OBD2 reader ($15 or less on Amazon). The same code that works on gen 3 works on gen 4 (I have both)
the Dr.Prius app has an option to switch off the backup beep - you do need a bluetooth OBDII dongle to use with the app
I asked the dealership to turn it off on my first service at 5000 miles. They advised me to think of everything and anything I wanted changed on their Tech deep dive computer access vs. what owners can do on their screen bcs they only offered a one time at no charge courtesy. I am SO thankful I had them turn it off as I found it just so incredibly annoying particularly if I was on a phone call when backing up. Note that it does still make one single beep when first going into R but it's fine.
My dealer has done this for me on both of my Prius plugins. They didn't charge me; it was Toyota Place in Garden Grove, CA. Posted via the PriusChat mobile app. AChoiredTaste.com
Some dealerships will do this as a courtesy as part of the sales make-ready. Others see it as a service department revenue source.