Is 12.3v at the battery terminals low enough to cause trouble?(?Yes?)

no, the 12v is not the problem. You need to get a code reader to see what's wrong with it.

Just having purchased the car, I suspect the previous owner can probably point you to the problem (but will deny knowing anything about it).

 

replace the 12 volt battery with a good quality one then reset the error codes and the lights should go out, while you have the battery out push out the rubber drain plug in the bottom of the car as sooner or later all these cars leak into that area.
good luck

 

resetting the car and getting rid of the lights, does not fix the existing problem.

 

Yes, I agree with JC. Do not reset the car without reading the codes first. Then if they come back, you can read them again and check for consistency. There is really no way to know what the problem is without the codes.

 

I too vote with the majority on this one. 12.3 volts is weak, but still should work. It sounds like there is a issue elsewhere that needs to be addressed first.

I would get the offending system that is causing the abs light/red triangle etc. to come on fixed, then consider whether or not I want to invest in a new 12 volt. Based on age alone, it would not surprise me if you will need to work on the traction battery, but again the codes are what you should go by. Anything else is just a guess.

Best of luck to you.

 

I think you should first check to make sure all the recalls on the car are completed. If not, that could easily be the cause and it wouldn't cost a dime to fix.

 

You reading the 12v battery under load such as with lights on?\

Ya the previous owner could have known there was issue. You can get a code reader for far less that it would cost for a shop to read the codes.

 

12.3 volts is not that low where it would create problems for the Prius. Replacing the battery will not do anything

 

I've been keeping a close eye on my aging 12V battery and have been seeing voltages as low as 11.9 no load, 11.7 accessory mode (no fan or lights), and haven't had a problem yet (I'm replacing the battery next week). I've heard here of voltages as low as the high tens and the system still boots up. 12.3V is a good day in my car.

 

11.9 volts is what I saw, after forgetting the driver's door open for about 18 hours. I'd hazard a guess a battery at that voltage for some time would be deteriorating rapidly.