Suddenly, one day, the red triangle warning showed up and my OBD2 code reader said the Hybrid Battery was bad.
The code reader showed P0A80
though with the last run of the engine – before the no start problem – I had started the engine and saw that the battery monitor showed that the battery was charging normally so I decided to take a short test drive on the road. After driving only about 1,000 feet, the battery monitor showed that the charge level was continuously dropping, so I turned around and drove back home. The car died about half way into my driveway, showing no bars on the battery monitor, and would not start again. The safety disconnect plug was definitely installed correctly before I used the Torque Pro app for diagnosis, and before running the app I had checked the connectors to the control unit. No damage or corrosion.“
The RTOD was the first thing noticed, and I was headed home at the time (about a 30 mile trip from where I was when the RTOD showed). I switched to the energy monitor screen and could see that the hybrid battery was not charging normally. It appeared to be getting worse as I drove further, in that the blue bars became green bars, and there were less bars. When I came to a slight hill right after a stoplight, The Prius was barely moving and I wondered if I would make it home, but once the road leveled off things became a bit better and I was able to limp home. As soon as I pulled into the driveway, I hooked up my OBD2 code reader, and it showed the POA80 code.
At that point, I decided to rent a vehicle for one week while we searched for another car. I didn’t have time to mess with the Prius because my wife needed a car for driving 40 miles to work and back, and we were due to move out of the home we were renting in just 2 weeks, moving back to our rebuilt home which had been burned to the ground 10 months earlier. I needed to take the Prius to the garage of our rebuilt home (the garage had not burned, thank goodness), and since my daughter was coming for a visit I had her follow me while I drove the Prius. That was the day after the RTOD incident. Strangely enough, the Prius ran just fine that day, and showed that it was charging normally, until I was about 3 miles from my 30 mile destination, and then the bars started going green again and diminishing. I made it to my garage and parked the car inside, where it remained by its lonesome until about 3 weeks later, before I had any time to spend on it.
In thinking about why the Prius might have gone haywire just 3 miles before my destination, I wondered if it was because I was passing over a rough road at that time. It seemed logical that the rough ride over that stretch of road could have caused an electrical connector fault if the connector was loose or corroded. In searching the Internet, I found that the hybrid battery fan connector, as well as the battery ECU connector, were prone to corrosion problems due to dampness from a leaking hatchback seal. So, when I could find the time, I checked out the fan and fan connector, and all was well there. The ECU connector was also good, and so were all hybrid related fuses, so that shot down my hopes of a simple and easy fix. That’s when I decided to get the bluetooth OBD2 reader and the Torque Pro app. And just after taking the voltage readings on the 14 blocks, I attempted to start the Prius and found it appearing to be charging properly again. That’s when I gave it the short road test, and headed back home very quickly when I saw the charge level dropping off rapidly. That was just a few days ago, and the Prius hadn’t started again after that, so that’s when I decided to remove the battery cover and inspect the bus bars. Naturally, the copper contact bars looked mostly black after all those miles, with a bit of green or blue here and there, so it made sense to remove and clean all of them, which I have done. My last effort was in obtaining the individual module voltages to determine which one, or ones, I would need to replace. While I only plan to replace #9, if 2 and 11 turn out to be okay, I have ordered two extras just in case they are needed now or in the not too distant future.
