Gas engine dies in the middle of driving

Hi all
We have a 2007 Prius that we got a couple of years ago secondhand. We're driving it in Oklahoma, and as I recall, I think it's not lived in the north. We got it through a local mechanic who knows how to service hybrid batteries, etc. I think he had reworked it some before we bought it, but I had the understanding he got it from an auction or similar.

Last fall in October, I had the car gas engine die while I was driving a couple of times (once while I was on the interstate!). I found that if I pulled over and restarted the car, it would work again, even though the red triangle was on. The mechanic got the codes, but it didn't give a clear idea of the problem. He sent us to the dealership. They had it for a week or more and couldn't replicate it either. And once I got it back, it never did it again until about a week ago.

We suddenly had really hot weather (high 90s), and when I ran a bunch of errands with my teenage son, it did it at least 4 times in one or two days and did it again on the way home from church on the weekend. A couple of times, it was within a few minutes of starting the car, but definitely not every time. Thankfully, it hasn't happened when on a highway. The electric motor is always enough to help me get safely to the side of the road. I turn the whole car off and back on (even quickly) and as soon as I've done that, the gas motor will work as usual.

I took it back to the dealership on Monday (the mechanic said he would be out of the shop all week). They can't replicate it. The codes don't lead to a clear solution. But the service person says that the mechanics are saying that they've solved similar problems by replacing the gas tank (to the tune of $1050 parts/labor). He says they suggested it last fall, but I didn't hear it (hubby says he recalls hearing it as a minor suggestion). (Side note: It's my regular driving car -- hubby drives it extremely rarely, and I'm more mechanically inclined than hubby, but I don't get talked to about it seriously very often... aggravation!)

Sound familiar anyone? Does this sound like an appropriate fix or just a huge waste of $$? I only drive it a 16-mile commute 4 days a week and local errands (up to 25 miles away from home) with the rare trip (rarer because of COVID). It doesn't scare me to keep driving with it doing this, but I figure I should get it fixed sooner or later...

 

"up north": We bought the car used. I didn't get a full, regular carfax on it, but I got something and I think it's mostly been owned in the southern states. For some vehicles or problems, this is helpful information.

The code that the dealership saw simply says that the gas engine failed to start. P0A0F. No other codes. As I recall, it was the same last fall - just the one code. This is a big reason they're not sure what's going on, especially when they can't make it happen again even though they have it for days. Last fall, I had the mechanic check it also, and the same result. They hadn't told me the code yet - that's why I didn't know it - I got it today when we picked the car up. They definitely knew it - had mentioned it, but I hadn't written it down before.

I only use the electric motor to get to the curbside as quickly as possible - less than 100 meters. Just to a safe enough spot to park long enough to restart the entire car. Are you telling me that I'm ruining the battery just doing that??

I'm not sure what you're trying to say about the hybrid battery. You're sounding blustery.

The (pink) inverter coolant was definitely circulating/turbulent as soon as I push-buttoned the car on.

So far, this thread is the only one that sounds a bit like mine as far as what is going on and the codes that are seen. I do feel like it drives just the slightest bit like a gas-only car that has a spark plug misfiring at times. Most of the time when it jerks ever slightly, it's switching between using and not using the electric motor per the screen - so I don't know what it is.

 

Update for anyone curious. About a year ago, the dealership changed hands and a lot of staff changed. Was able to tell a mechanic directly what was going on, and they replaced whatever computer component controls the switching back and forth between the electric and gas engines ($800) and it never occurred again...
Then just before the new year (about 4-6 months later), another vehicle on the highway lost control, ran into us, and the Prius was totaled.
It was a great car - I miss it - but I'm really enjoying my low-mileage 2010 I finally found to replace it.