Car doors won't lock. Car keeps beeping at me when I turn it off.

Always check the 12v battery when strange things start happening.

 

They are talking about the 12 volt battery in the right side of the cargo area. That battery runs the computerized system, lights, etc/ It is recharged from the larger traction battery.
When this battery starts failing, many unexplained issues can occur. IT is pretty easy to change, much like a traditional automotive battery, but designed for deep cycle rather than cold cranking amps.

I believe this is the battery.

 

By all means check the battery but locking problems can be caused by failing actuators in the doors too. Mine was intermittent before it failed completely. That is a common problem.

 

Common? No. Rare is a much more accurate diagnosis.

 

Door actuator failure is common in all cars after years of use
My driver doors recently went from intermittent to failure.
Lots and lots of threads about it here just search

Door actuator

 

But it seems to happen in some Toyota models MUCH sooner than you would expect.
I was lucky. My first one failed in less than 3 years of light use and was covered by the 3 year warranty.
Given what the dealers charge if not under warranty, I might just trade mine in when the next one fails.

Many threads about it on here. Like you said, I don't see how anybody could call it "rare" after reading those posts.
And visiting other brand forums and NEVER seeing it mentioned at all.

 

I have never had it happen on any Toyota I have owned. (1969 Corolla, 1989 Camry, 1996 Camry, 2000 Tundra, 2008 Corolla). My Prius is too new to include in that list, though.

 

Well the discussion here IS (mostly) about Prius models, after all.

And what did or did not happen on models over 20 years old can hardly be significant to what is happening today.

There is very little to make legitimate complaints about with the Prius line but I think the door lock actuators IS one.

 

So I have also just experienced exactly what is described above. I signed up just so that I could post this reply in the hope that it will help -someone-.

As above, the car beeped when turned off, beeped outside when I walked away, and would refuse to allow the doors to lock (even if I pushed the door lock myself, the car would immediately unlock all doors).

In my case, the problem turned out to be this: a usb adapter plugged into the 12v port (cigarette lighter) at the console with a cell phone battery bank plugged into that (I was charging it while driving, and left it in the car when I got out). When it was finally unplugged, the car made a happy "yup, that was it, thanks" beep.

2015 Prius V Five

 

Thanks for posting but you’re in the G2 forum. You want to post this in the G3 forum.

 

My apologies! Posted in Doors won't lock | PriusChat

 

holy! i was browse this forum becasue i cant lock my car, after u read your reply, i look at my car realized i pluged in a power bank to charged it, now i unplug it everythinf goes back to normal, thx!

 

I too just signed up on this website to post that this was my fix for my 2007 Toyota Prius just now! Normally nothing charges from the USB ports after my Prius is turned off, but for some reason I plugged in a hand warmer that continued charging after my Prius turned off. That was the culprit! The doors now lock normally again and no more beeping after the USB device was unplugged

 

I had the same issue, thanks for the clue! I was charging a flashlight battery in the cigarette lighter and when the car turned off, this continued charging. Unplugged it and the problem went away! It was NOT the door actuator

My experience of the problem was as followed:
When I turned the car off and opened the door, the car would beep steadily as if I had clicked the power button once without pressing the brake, like it was in Accessory mode but no lights were on. Locking the doors resulted in an immediate unlock. I should have noticed something strange when the cigarette lighter was still working with the vehicle off. Unplug anything from the cigarette lighter and see if this fixes the issue before you go through Any mechanical issues