P0A80. Driven a couple of times and now have HV fan on constantly and limp mode (?)

Pretty normal symptoms for a HV battery that has a failed module or two. Many times the codes can be reset and the car will drive semi-normal for a little while, especially if you baby it. As time rolls by, it will code out more and more frequently. I've also met many people who have done it many, many times while putting off the repair job. There's no significant difference in battery damage.

I've reset a P0A80 and done short drives several times while evaluating a car.

 

I've experimented/gathered data from really bad packs in my car and having a bad module can be confounding... I can plug in the OBD2 reader and turn on Dr. Prius app and take screenshots and clear the red triangle as many as 5 times in one day and it only takes less than a minute for everything to be back to normal and then inexplicably that bad module will work great with no red triangle for as long as two weeks.

Main thing when it comes to module failure is that the car will protect itself sooner than later and if you clear error code/tell it to forget problem, car can go for a while longer.

Of course I'd only recommend doing that if you have multiple packs available and you're working on a pack in this way for the sole purpose of data gathering, rather than trying to ignore the problem because if you aren't fully prepared for all the repair work requires things can go from bad to worse real quick.

 

Yes... You can disconnect the 12v and give your car amnesia and see how long it takes to notice again , but to do so without knowing what the actual error codes and subcodes are is about smart as trying to drive while keeping your eyes closed as much as possible.

And as I've said before, some error codes are a relatively minor easy fixes, like corrosion or clogged fan related problems... And while you're waiting on your mini-VCI, you might want to double down on your odds and buy an OBD2 reader so you can use Dr. Prius App on your phone to get codes, because in the long run it's much less work getting them seconds after they popup that way. Learn more about buying them here: Hybrid battery diagnostic and repair tool for Toyota and Lexus

 

Anyone reading this for a fix, regarding this last post, dr Prius will only give you limited readings of codes. You can not get any ABS codes from DR Prius. Primarily battery codes....it says 'engine' codes...I haven't narrowed down what that includes...as I use tech stream. However, I use Dr P for live battery monitoring. Just an FYI, Dr Prius is not an all inclusive OBD2 scanner.

 

Dr. Prius app is perfect for when you're driving down the road and warning lights come on and you grab your OBD2 reader out of the glove box and plug it and read what codes are available and then take some screen shots and clear the codes.

The maker of the app wisely decided to limit his app abilities so as not to be a Toyota Techstream hijacking... There's plenty of other online folks who will help you with that.