Warning sound (continuous scream, not a beep) when reversing

Hmmmm....any time a hybrid has a strange electrical gremlin my first question is always, "How old is the 12-volt battery?" Sure it may let the system start but if it's about dead, can cause all kinds of trouble. Get it tested free at an auto parts store if you don't have a tester. (I've found 70% or less means it's about time to replace.)

 

At the beginning of that video there is a continuous tone (which I can barely hear, too high a frequency for me) but the car isn't in READY, not sure what is going on, lots of lights flashing. What does it mean to put it in reverse in that state, or even, how can you?

Assuming it does that when the car is in a normal READY state, and only in reverse, I would guess that the tone generator circuitry is on the fritz. Maybe pull the fuse for the radio though, it could also generate a spurious noise, although why it would do so only in reverse would be a mystery to me. Or that tone could signal some other problem like with the brakes or the transmission. Was it tested in any other transmission setting besides park and reverse? That is, does it go away when the car is rolling forward?

 

We're getting way ahead of ourselves here you have abs buis going on I believe let's start with code read not paper clips . Most of this stuff is old wives tales that people have just been doing because they didn't and so on . Test not guess .

 

do you think there will be codes with no trouble lights?

 

Is that noise coming from right behind your CM display ?

 

Very good now see if you can locate where the beeps coming from I know It's tricky you want to listen above and behind you're speedo. There's a speaker on the back of the board of the speedometer ittends to beep or chirp at brake issues and other.. is another beep chirp added if you open the door if you open hatch . The alarm /Immo is not active . I have to know what's making tone . They're a few speakers on car . Not the ones for the sound system

 

That's not either / or: many systems in the car let you use a paper clip to read codes.

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

It's the fastest way to get the codes if you haven't already got a scan tool.

The OP did say there are no warning lights though.

The only continuous beep on purpose that I know of is the one for severe brake system issues, but there would also be brake warning lights and codes with that.

This could be something much more off the beaten path, like wires getting crossed between the back-up lights and the brake beeper.

Might have to start by ducking under the dash to try to be sure which little beeper is making the beep.

 

A lot of these tricks on the internet you see people doing aren't to get blink codes they're jamm8ngvstuff into connectors not knowing Wth they doing . Getting blikies is one thing . But the paper lip nonsense all over the net is shady at best. Of course as they break them down here in the South I get them for near nothing so paper clip away.