OEM 2008 Prius Hybrid Battery Replacement

We have a 2008 Prius that needs the hybrid battery replaced. I can get it from a local Toyota dealer in a few days and will be replacing it myself.

It is my understanding that these replacements are not just drop in and go. My question is what parts off the old battery do I need to swap out with the new battery from Toyota?

 

Thanks for the links! I think I have read some of that but, it wont hurt it go back through it again. Battery isnt due till Wednesday so, I have a little more time to study up.

 

Well, the battery came in Wednesday, picked it up Friday and started the replacement yesterday. This is not that tough of a job and the key is organization of all the bolts and pins. (or so I thought) Anyway, got it swapped out and before bolting everything down, I reconnected everything and tried to fire it up. It ran a few seconds before throwing two codes I had never seen before. P3191 P0A0F

These codes were not present before but, they sure are now. After some reading, seems they are no start codes. MAF, throttle body and 12v battery seem to be everyone's suggestion to start with first. I will do that later today. My question is, if theses codes were not present before battery replacement, isn't it highly unlikely these codes are not related to the MAF, throttle body and 12v battery? Meaning if they were a problem, shouldn't or wouldn't they have showed up before?

Kinda baffled on this one. Going to get some cleaner in a bit and see if that helps. My guess it wont but, never hurts to try.

Any ideas?

 

Good evening and thanks I appreciate the suggestions. I spent the better part of the afternoon re-checking my work and everything seems to be as it is supposed to. I did end up taking the case back off when doing this and I did put a couple of bolts in the case on the backside (towards the hatch). I also cleaned the MAF and throttle body, put a trickle charge on the 12v. The gas tank was 98% full when I made the swap so I know its got plenty of gas. As one of the replies questioned, I did unhook the 12v battery while doing the repair. I did not remove the neg or positive at that time, I pulled the two plugs connected to the battery. This afternoon, I removed the ground for an hour or so to see if any of the codes would clear. I then hooked it back up and put a trickle on it for the hell of it.

Put the safety switch back in, tried to start, same results.

Another thing that I noticed when the motor tries to fire, it sounds awful rough. Feels like the engine is shaking. Never heard or felt that sound at anytime in the previous 13 years.

Im done for the day thats for sure and guess I will go back and do some research and reading before starting back at it tomorrow after work. Again, thanks to those who offered help!

 

It is a pretty simple changeover. Don't be discouraged by whatever is going on here. If you have any common sense and two good eyes, you can do it. Take pictures of the old and new battery before starting and lay everything out organized as you go. Youtube is your friend. Cannot tell you how many hours of videos I watched to make sure I did not screw up. Went and re-watched some of them yesterday to make sure I did not miss something.

Car has sat for 10 days as of today. 12v battery was checked on the mfd and terminals when diagnosing the hybrid pack. IIRC, it was 12.6 acc and 14.2 with a load. I had HOPED it WAS the 12v. It checked good at the time but yesterday was a little low at the terminals so I trickled it back up. Battery is almost exactly 7 years old and has given zero issues since installing. I suppose its possible she gave up the ghost in a few days but, my luck doesn't work that way.

I am going to go in and test it on the mfd after work today and see what it says. It will have sat for close to 20 hours by that time. Other than that, that's all I have planned to do. I don't want to keep taking small swings on the new pack. I understand your tries can be limited and I don't want to go down that hole.

Air, fuel and spark. I did clean the MFD and throttle body so, I'm confident with that. I had just filled up the previous day and the gauge is reading full bars so, pretty confident there. Spark, plugs might be next on the list to try.