Diagnosis assistance

Good day all, I'm 10 months in with a second hand 2010 prius. During the past couple of months I've been having an issue with the vehicle. First it started with a message appearing check hybrid system appear on the display at the time the vehicle had about 98000 km on it, I took the vehicle into the only Toyota dealership here. They cleared the code and said that the hv battery needed replacing to the tune of $13,000 which is around USD $6,500. They refused to give me the specific code that was thrown, they have some weird policy which I'm sure has to be illegal not to give codes or part numbers for parts on vehicles.

I drove the vehicle for 1 week and bam message appeared again. To be more specific at that time the engine was running more than it should. This time is the time I discovered priuschat, so since I had no way to read the code I disconnected the 12v battery from the vehicle for 5 minutes or so and cleared the code. I found a garage who could do a diagnostic on the vehicle and it was told the vehicle needed servicing. So I brought in spark plugs, changed the engine filter and did an oil change. Car drove well for about a month then I got the message again (while driving again). Remembering what others have posted on here I decided to get a check on my 12v battery. They said it was bad and had to be changed. Changed it not with a oem battery but a sealed maintenance battery I proceeded to have 5 months without an error.

About a month ago while driving the engine started running excessively without shutting down when its supposed to shutdown again. Then the message showed again, as soon as the message showed the ice stopped running and the car worked like a charm. I searched around to finally get someone to read the code and it was P0A7F, he cleared the code and car has driven well since then. So I started digging around and then decided to clean my hv fan and the bus bars of corrosion. After all the cleaning since then I have had no codes but intermittently the engine would still run continuously while a shutdown was expected. The other day it started acting up again when I parked the car the soc was at 2 bars and charging, I turned off the vehicle. I decided to go and clean the car out so I had all my doors open, so to avoid battery drain I disconnected the accessory 12v battery when I reconnected and turned the vehicle on the soc was at 7 bars and no longer needed a charge.

So something is definitely up, I find it hard to believe that now with only 111000km (68, 972 miles) that my battery pack is actually deteriorating as per the P0A7F since its not alot of mileage and its been ocurring intermittently. I decided to order a obdII device and use the torque app to have and idea of what whats going on inside. It will reach me by Monday. So does anyone have any ideas what might be happening with the vehicle with what I said. I do apologise about the long dialogue to read.

 

Yea I saw this post, the only thing left really for me to do is to see the voltage output of the modules under load. I cleaned the fan and one thing I must say I dont hear my fan running at all

 

I would have to keep an eye out for the temperature, the thing is as I said I dont really hear the fan running

 

Well I did not wire brush the battery terminals, neither did I apply vaseline, I did clean the link until shiny though. So do you think I should go back at it again and clean the battery terminals and apply vaseline or an anti corrosive grease?

 

I will see if I can find the time to get it done this weekend and let you know if there is any change