I am new to this chat and I have a question. Seems like there are a lot of people here with good answers. I was driving my 01 prius the other day and out of the blue the car slowed and the engine started revving very high. I have an ODB II diagnostic tool. I plugged it in and I got a p3024 error which is Battery cell 14 becomes weak. I had noticed recently that the battery light shows a full charge green all the way to the top and it had never gone totally to the top before. It also goes up and down quickly. I've done a lot of research and I'm ready to pull the battery and replace the bad cell. I just don't want to take out the battery if that is not the problem. I have cleared the codes a couple of times and it happens again after about a mile or two. Also when I tried to back up it would not go at all one time for a few seconds. Then at that same time when it went backwards and I shifted it into drive it would not go forward for a few seconds. Then on that same trip I pulled into the bank and when I shifted it into reverse I got the steering wheel violently shaking like I've read about before. With all of these things happening, could it maybe be the ECU and not the battery that is actually causing this problem? I didn't not get any error code or warning lights when the steering wheel was shaking or when it wouldn't go backwards or forwards. I had gotten two other codes along with the P3024, but they were cylinder 2 and 3 misfire. I changed plugs and they have not returned. Thank you. Hopefully someone can give me some insight. Chad
Hey Chad, Those are all classic symptoms of a failing HV battery. The ECU's don't go bad often and you would have different symptoms. My bet is on the battery.
Thank you! I thought it probably was. I have owned the car for a little over a year and the guy I bought it from said that the battery had had two cells replaced before I bought it. The car has almost 300,000 miles on it and I've put about 40,000 on since I bought it, so it's not surprising. I got out of it what I paid for it in fuel savings alone already driving 130 miles a day round trip to work and back, so everything now is a bonus. I love this forum! And I still love my car! I'll post an update later when I start the fix.
Well to end this post, it was a bad cell. I bought some equipment, studied some things, got some documentation and then removed the HV battery. I took it apart and replaced the bad cell. Runs like a charm! 285,000 miles and counting!
He must work very quickly, buying the equipment and module then completing the work in 11 days. Unless he just fitted one module and crossed his fingers. John (Britprius)
With the HV Battery Analyser the test could be conducted in 1 day. I would say 11 days is far too long. Please have a look at 2 minute time lapsed video of it in action. Posted on youtube and linked in the Video thread Hybrid Battery Capacity Test | PriusChat
What about SoC of new module? It was at least similar to others? This battery does not have cells balancing.
