Anas1518

Hey, I bought a used 2008 RX400h with 92k original miles. It came with a bad engine so I had the engine replaced with a different one. With the new engine in however, I have codes and the car shuts off shortly after starting it. It has a new 12v battery from lexus so its not that. The codes is has are P3000 and P0A80. When I initially bought the car, the codes I had were P3193 and P0A0F and a knocking engine. Then I had my mechanic replace the engine and now the car doesn't seem to stay on. It starts the first time runs for about 2-3 seconds and shuts off and doesn't start again. Any ideas on what can be causing this?

LeX2K

Did you have those codes before the engine was replaced? P0A80 is telling you the hybrid battery is shot. It may be, but the problem could be elsewhere like blown fuse(s), incorrect assembly of the various wiring harnesses. When you say the engine stalls, do you mean the car won't drive? A hybrid shuts off the engine on demand that's how the system works.

Anas1518

Before the engine was replaced the only codes I had were the two P3193 and P0A0F. After the replacement it has the other two. I haven't driven a single mile in the car yet. What I mean about the car stalling out is right after I start it and hear the engine start up it sits for about 2 seconds makes shudders for a split second and shuts off.

LeX2K

If the hybrid battery sits for too long the charge will be so low that the engine will never charge it. This is a major limitation of Toyota's HSD I don't know of a good way around this. Apparently there are specialized tools only dealers have that can charge the hybrid battery. There are other ways to accomplish this but require advanced knowledge and skill.

edit- make sure the 12 volt battery is charged up, doesn't matter if the battery is new the charge could still be down. Worst case you can get a replacement hybrid battery they are not super expensive anymore. This is the first link that popped up in a search
https://www.besthybridbatteries.com/.../lexus/rx-400h

Anas1518

Thanks for all that. My only concern at the moment is 92k miles for a failed hybrid battery seems a bit premature. Not sure if it just needs to be charged or what the case is. The new Lexus battery seems to be working okay. I used a jumper on it before starting the car and left it on but had the same result.

LeX2K

Hybrid battery could be perfectly fine just needs to be charged. Charging it up is the hard part can verify by testing the voltage. Warning: hybrid battery has enough voltage to kill you.

Anas1518

Yea It isn't something I was planning on doing myself. The hybrid battery will read good voltage even if it needs to be charged?

LeX2K

No, the voltage will be way down.

Anas1518

Okay so essentially the dealer is my best bet in finding out whether I need a new hybrid battery or not

Margate330

Don't they make a special app or diagnostic tool for this car that will give the battery health?

I remember peeps on here talking about it but can't remember the name.

Dr Prius or something?

PS:
I work on machines so I wouldn't need a dealer to charge the high volt.
I'll look up the voltage specs.
Then using step up transformer, I'd rectify and current limit the output and bring the batteries up slowly.
But I don't recommended this for DIY because it can be dangerous to self and property if you don't know what you're doing, not worth it IMO..

LeX2K

There is a wealth of info you Youtube, one of many examples

Margate330

Thank you for dropping a link.

See that's the problem, there's too much info. imho
I think that's why people come here cuz a link from someone like you who is knowledgeable means a lot more than getting lost in a sea of info to people who are starting from ground zero.

Example if I may.
If I'm helping someone with a timing belt installation, I may scan thru a few videos and find just one that actually shows the real info and doesn't leave so many "gotcha's" out of the content.
So many videos and websites fail to mention pitfalls and other headaches and can cause more aggrevation than they help. lol

Anas1518

I'll look into the app. How exactly would it work? Since the battery level would be low in both situations (it needing charge or needing replacement), how would I determine what to do? Does the app distinguish between the two?

Margate330

Hi friend, I really don't know so I'm not much help on that but I do know there are tools or apps other members use.
I only help with the wiring and electrical but that all I have.

If the car has been sitting for an extended period of time, your High Volt Battery level may have dropped too low for the car to initialize and get ready.
Hopefully others have a ways to see clearly what's going on for you.

Anas1518

I see. Under my ownership its been sitting since September. Before that I don't know how long it sat wince it came with a bad engine