Multiple Dash Lights no codes on OBD

you need a prius aware scanner

 

see here:

autel-maxi-ap200-go-buy-this.232861

 

^ I'll second that.

I got a slightly different Autel model, but it uses the same app and does more or less the same. It was extremely helpful in sorting out a problem in our car recently.

Generic code readers can only detect generic codes. Hybrid cars (and EVs) have many, many more codes that the generics can't access.

 

From the symptoms alone, you've got at least one or more bad batteries in your traction pack and/or the pack isn't recharging as it should. You'll need a Prius capable OBD scanner to figure that out.

 

It is fair to expect that a 2012 Prius c will have a very tired traction battery by June 2024, and your drive symptoms roughly match that of a dying traction battery. Can't call it for certain without that Prius-aware scanner though.

The actual transmissions in these cars fail very rarely, but they can't do their normal thing without a good battery, and the batteries always go bad after 8-12 years.

 

If you haven't already done so, change the ATF. That'll get rid of some of the suspended partials in there. Any floating iron particles are probably already stuck to the transmissions electric motors.
Again, get the codes read before you proceed further. If you have to pay someone, make sure they give you a print-out.

 

The symptoms sound like the bad battery. Same thing happened to me. Here is what you do:

1) Under the hood on the driver side there's a small plastic box that has a thick white cable inside. Disconnect it carefully and reconnect after a few minutes. That will clear all the codes and buy you some time before you get the lights again. Make no mistake - you WILL get those lights again, it's only a matter of time. ( Alternatively, you can disconnect the auxiliary battery or even pull the orange plug on the hybrid battery to clear the lights.)

2) Meanwhile you can start searching for a battery replacement. You can do it yourself, it's a very easy job, takes 30 mins and only basic tools. Personally I got a good one from a junkyard for $700 when my original one failed at 227k miles. Good luck!

 

If OP has never changed tranny oil it would probably be a good idea to do so as well. Personally I use Amsoil atf that comes in soft bags that you can easily squeeze into the fill hole like toothpaste. Also a very easy job, basically as easy as an oil change. An honest mechanic would do it for like $50 if you don't want to diy.