Have you seen this happen? I own a 2002 Prius which I drive up and down a mountain (Haleakala on Maui) almost daily. Earlier this year the triangle of death came on. The Prius had 140,000 miles on it at the time. Codes were P3018 and several others (including a broken bus bar). Here's a quick summary: Instead of going the new battery route, I purchased five cells from Ted Barcelon. We disassembled the battery, replaced the faulty cells, and also fixed the broken bus bar. This was in July of this year. The car worked fine after this.... We cleared out the codes and the triangle, check engine light, and any other error lights were gone. That is until October rolled around. The same set of lights came on back on (photo attached). When we ran diagnostics, the error code spit out was P3018... So I ordered more cells from Ted, took apart the battery, and proceeded to measure voltages on all the cells. They all checked out fine. I did take the time to do an even more thorough job of cleaning the bus bars and the heads of the cells (than before) to insure a solid connection. After putting the battery back in, we cleared out the codes, and the car proceeded to drive fine. Less than 100 miles later the check engine and other lights came back on (same ones in the attached photo). I've continued driving the car and it runs fine. The error lights will be on for like 75 miles, then they'll turn off (everything back to normal), and then the error lights will show back up within 30 to 50 miles. Make sense? I am wondering what the issue might be. Thoughts? Have you seen similar things happen? Thank you for joining the conversation and sharing your thoughts, Ramu
The Prius GenI batteries are much much much more prone to failure then the GenII and beyond. Your age is about right for a pack failure at this point especially with the mountain in your commute. Hills and heat kill, you have both. A double whammy! Just replacing 1 or two cells can be done, but it is an art. You cannot pick 2 random cells and put them in a random pack. You must match the cells to the other good cells in the pack. This usually involves picking one of 30-50 cells available. So if you need to replace 1 cell, it is best to have 30-50 cells at least available to find one with similar capacity, ESR, and life. You chose cells at random and this is what happens. Your new cells are not matched at all to your old cells. If we assume the cells you bought were new or at least barely used and healthy, then we can assume that under load they do not drop as low as the old ones making the delta bigger which can trip the fault and shut it down. So if your old cells hover at X volts, and go down Y volts under load, the new cells are maybe going down Z volts | Y << Z. Also when charging during regen or any engine charge the old cells will charge up very fast because their capacity is reduced. So the good cells will be starved of charge. The rest of the cells will try and balance which is like an infinite game of pass the hot potato. And heat will be generated by this as well internally. Your options are: 1) Get a new pack 2) Get a newly professionally rebuilt pack (I think there's a place in Australia that does it as well as on the east coast of the continental us) 3) Get a new professionally made pack with GenII cells that will last much much longer, wont have the corrosive bars, and have higher capacity for less money 4) Find a bunch of old cells, balance and measure them. Balance and measure your cells. Pick and choose enough to completely replace your pack yourself that are close. 5) Buy a bunch of new GenII cells and do the same. 6) Continue to play "whack-a-mole" replacing the failing cell when it fails knowing that the act of replacing it if different enough is a death warrant for all the different cells in there which will then need replacing. It will never end until they are all pretty much the same.
I had an issue with my 2008 that caused the low tire pressure lights to go on, but when brought in for diagnostics the tires were fine. Ultimately it happened right at the dealership shop and they determined the electrical equipment that causes these lights to trip was the problem. Dealership switched it out and it never happened again! Why keep replacing things on your own......have them analyze it.....especially if the vehicle is functioning correctly.
@ 2k1Toaster Thanks for your feedback. Your explanation makes perfect sense. I plan to ultimately sell the car, but I really don't know if anyone would buy it in this condition. Probably not even the dealership. What I'm considering doing is as you mentioned, "Get a new professionally made pack with GenII cells that will last much much longer, wont have the corrosive bars, and have higher capacity for less money," and then from there selling the car. I don't expect to get much for it. @ bwilson4web Code is P3018 @ etobia I took the car to the dealership the first time. They wanted to replace the battery for approximately $4k. We ended up doing the repair which has proved short lived for about $200.
