2005 Gen 2 - Red Triangle, P3000 Code, ICE won't start

I just had a catalytic converter shield installed by my mechanic on my Gen 2, 190,000 miles, but when I started the car to take it home from the mechanic, there was the Red Triangle, VSC, and the yellow exclamation in a Circle. The gas gauge also flashed repeatedly, from no bars to full bars, despite the car having recently been filled up with gas. On the MFD it also read "Problem," and the "Red Prius" icon with an exclamation point appeared in the upper left corner

The ICE wouldn't start at all. On the MFD I could see the Hybrid battery had only 2 bars left.

This morning I had driven the car to my mechanic with no problem. I have been using this mechanic for many years, and all he did today was install the catalytic converter shield. A few days ago he had also installed a brand new catalytic converter (since mine was stolen last week), but my car was driving fine with the new catalytic converter installed, until this happened today today.

We tried to disconnect and reconnect the 12v (the 12v is still healthy, voltage reading over 13v, bought in 2018). We tried using an additional power source hooked up to the 12v. We tried adding gas (even though the car was probably 7/8 full). Nothing worked to get the ICE to start.

Another factor (probably unrelated) is that my Combination Meter has been going bad, so sometimes I need to do the headlights-open door trick to get the dashboard to light up. So I thought, maybe the mechanic left the car running without knowing it, because the dashboard might have been black, causing the hybrid battery to run down? But this hardly makes that much sense, because normally the ICE would simply kick in if the hybrid battery gets too low.

The mechanic ran his scanner, and pulled a P3000 code. He said the hybrid battery needed replacement. This is obviously very bad news. I replaced the hybrid battery once before, in early 2018, with a reconditioned battery from a place called Electron .

Can anyone help with this? Can a Red Triangle suddenly occur like this, without any warning, and would it prevent the ICE from even starting? Am I missing something? Please help as my car is still at the mechanic and I need to figure out ASAP what the next step is going to be here...

 

The mechanic just gave me the P3000 code, I asked if he had any other codes and he said no.

 

Would I be able to pull a more detailed code using this bluetooth OBD2 reader, and the Torque app?

 

There is also a U0100 code that is on the printout the mechanic gave me. "Lost Communication with ECM / PCM A"
As well as P30000 "Battery Control System."

 

I pulled codes using Torque and my Bluetooth adapter, and it didn't give any additional codes.

The mechnic and I took another look to ensure that the oxygen sensor wires were not somehow damaged by the cat shield and touching the metal, possibly causing a short. The wires seemed to be fine. He is fully convinced that the hybrid battery has failed. It's a reconditioned 2013 battery which I bought from Electron Automotive back in 2017. And which has performed perfectly, until today.

But would a failed hybrid battery completely prevent the ICE from starting?

 

How can I see those codes? Would an app like Dr. Prius show them using a normal Bluetooth OBD2 reader?

 

Thanks dolj and Brian1954.

Looks like the Autel AP200 is around $60 on Amazon, does that sound right? Would I be able to use it in both of my Priuses (2005 & 2016) without any kind of subscription or paying more for something?