Won't start, dashboard lit up

Hey guys,

2009 Prius base, about 162,000 miles, driving about 35 mph and the triangle of death, VSC and yellow brake lights come on. Drove normally until I got to work, shut down normally, just a display of idiot lights until shut down. After work I tried to start it and not just those lights but the lost traction light, hybrid system, and check engine lights were on as well, and the ICE didn't kick in - pretty much like when all the lights come on when you first start it but they don't all go out and the ICE doesn't crank. The car won't go into ready status. I tried shifting into gear and it would slip into neutral even though I was going for drive and reverse.

I thought maybe the 12 volt battery because of the weird ways these cars can get when the 12v goes low so I tried to jump it and it still won't go. The battery on both my tester and the MFD showed 12.4 no load, and when I hit the button like I was going to start it the voltage dropped to 11.9 volts. Turning on the headlights while in this mode it dropped to about 11.6 volts.

The battery is almost 6 years old but the voltages don't seem too awful. I would think even if it were the 12v battery it would have jumped anyway so I just don't know. The fact that it won't jump makes me think something besides the 12v battery is wrong.

MPG's haven't dropped (50 ish MPG average), HV battery charging and depleting seem normal. I have no codes since the car won't start to get it to anyone with a reader.

Anyone have a clue? Thanks in advance!

 

Well, I borrowed an OBDII scanner, pulled no codes and any info it had said everything was ok. Maybe not a great scanner and it wasn't up to the challenge, IDK.

What I did do was disconnected the 12v battery for a few minutes hoping for a reset so it would crank and I could get it home from the parking lot at work. Good news is it did just that that. Bad news is I don't know exactly what caused it and when it'll trip again.

When I got it home I looked in the reservoir for the inverter coolant and the pump was running, saw the ripples in it and all looked good there. I suppose it may be an intermittent thing? Maybe a simple man's wish but I wish not ALL the idiot lights lit up for EVERY malfunction...lol.

 

Well guys, bought a new 12v and installed it. She started and went ready but not long after the lights came back on. Sitting in the same boat only with a new 12v battery. Old 12v was pushing 11.8v so I figured it was a little weak and might be the problem but apparently that’s not the main issue. Starting to think the big battery?

 

New one checked in at 12.6v, I need tech stream or something that’ll pick up the error.