Transaxle Failure

Hi there,

I have a 05 Prius with 127k miles on it. A bunch of lights came on when I was driving the other day, along with a not so good sound when slowing down. I had the car towed to the dealer and they came up with these codes: P0A90, P0A09, B2799, P0300, P0302, P0303, P0304.
They told me that means the transaxle needs to be replaced. They quoted me $4800, 4k for parts and $800 labor.

I bought a Factory Manual and a transaxle off ebay for $700 and am planning on putting it in myself next weekend.

I have seen the article on Arts Automotive about replacing a gen1 transaxle. Has anyone done this to a gen2? Any advice?

I will be sure to post photos of the repair. Thanks a lot!

Interesting!

Any symptoms before the failure, unusual noises?

Take lots of photos. Folks will be fascinated with your progress.

Bob Wilson

Thank you for allowing all of us to tag along from the beginning of this process.

When you post photos, please try to provide a log in which you describe what each photo represents.

By the way: :welcome: This has to rank as one of the better first posts on PriusChat!!

Yes an excellent first post gung-ho attitude, but sad that you got hit with the apparently rare failuerein your model.

The folks at Art's are communicative by email so I am sure they would be willing to share hints on the task you face. As with all major Prius projects I suppose the first step is the same - remove the windshield wipers

My concern is the possibility of collateral damage to the electronics, and I don't know if your DTC list allows us to exclude that. Maybe ask Art that also?

Absolutely no unusual noises, which is what was strange. I pulled out of the parking lot and the lights came on at the same time the noise started.

I will be taking lots of photos. It might be a week until I start since I just ordered the transaxle, but I will keep you updated.

Thanks! I wish it were not such an interesting post! Cuz then I would not be in this situation...but hey life will go on and I will have some good experience.

Will do, as far as the photos go. I will try to take as many photos as I can.

You can look up the codes in your new Factory Manual.

P0A90 is Drive Motor "A" Performance. It actually refers to any part of the transaxle. There are a bunch of subcodes that indicate more closely what is wrong - some indicate MG1, some indicate the input, some indicate the output or MG2. However, if Art's experience is anything to go by, you'll find a rebuild difficult. I would check that the subcode isn't 241, which indicates a transmission input damper failure. (You still have to separate the engine and transaxle to get at this part, so it wouldn't reduce labour very much, and there's a fair bit of diagnosis before reaching the 'replace input damper' step.)

Subcode 509 can potentially indicate an inverter failure, rather than a transaxle failure. The diagnosis asks you to check the resistances of the motor windings. Code 604 and 605 ask you to check the battery current sensor before replacing the transaxle.

P0A09 indicates that one of the signal lines between the DC/DC converter and the HV ECU is stuck low. It looks like these are digital comms signals that are expected to pulse between low and high voltages - voltages close to the ground point or the aux battery voltage are not expected. You should check for a short here first - if the DC/DC converter is shorted out, it could well be dragging down the traction battery voltage and causing the other problems.

B2799 is an immobilizer code. Given the other symptoms I think it's likely to be logged simply because the READY signal wasn't received within 10 seconds of pressing the power button and can probably be ignored. It might be worth checking for shorts in the connection between the HV ECU and the transponder key ECU.

P0300-P0304 are misfire codes. The last digit indicates the cylinder that misfired; P0300 is a general misfire code. If there are problems in the transaxle the engine is unlikely to start or run properly; I suspect these are symptoms rather than causes.

How much diagnosis did the dealer do before announcing you needed a new transaxle?

Yeah, it almost looks like the inverter is blown as well according to the codes...I will check with Art's as well as the dealer.

The dealer told me that they checked each individual component since all the different codes came up. I am getting the car back today and I will check all the components to double check.

Thanks for the advice on the input dampener. I will check into that.

Yeesh! Is there any other history behind this?

It can be driven or towed?

Bob Wilson

That's a pretty impressive undertaking. I assume you're equipped
with all the necessary lifts, engine-lifting tables, and other
tools? You're aware that the engine/tranny is generally taken
out through the *bottom* of the car, right? Definitely please
do an in-depth writeup with plenty o' pix, and if you have a
chance to do any additional diagnostics to narrow things down
[ground-fault checks on motor windings, scope readings on various
parts of the inverter, etc] that would be great info too.
.
What sort of bad noise did the car make after the failure?
.
_H*

I have never had anything wrong with the prius before this. It has been perfect and I have been keeping up on the maintenance. There were not even any warning signs, no noise until the day all the lights came on. Maybe it had problems before I had it (I am not the original owner), but I have no idea.

I had it towed to my house...it still runs, but I don't want to take the risk of driving at all.

Yes, I am aware that the engine comes out the bottom of the car. I do not have a lift for the car, but I do have a bunch of jacks and equipment I can use....I have enough that I will be able to get it done.

I will do as much diagnostics as I can and I will take a lot of photos. I plan on starting some diagnostics tomorrow and I may possibly start pulling the engine...we will see how much time I have.

I talked to the dealer again today. They said that there were no sub-codes at all, just the codes that I posted. I will test all of the individual units as per the manufactures manual to be sure as I can though.

Update: I picked up the prius from the dealer today and had it towed to my house. Couple interesting things of note: When asking about the codes to be sure of them the manager was flipping through his paper work...I was reading over his shoulder (I know bad me) and saw the parts estimate from toyota, they quoted him $2000 for the transaxle! He quoted me $4000! Am I crazy or were they trying to rip me off. Maybe I should call Toyota and let them know....hmmm. Also, I never knew about the tow hook that screws into the front bumper. I was always wondering what that round cap was for on the bumper. Ha! The tow truck driver showed it to me and also showed me how the previous tow truck driver hooked up my car incorrectly and bent two holes underneath my car on the frame...its a good thing the damage was not more.

Ok, well tomorrow I should have another report after I do some diagnostics on the car. Bye for now...

The transaxle MSRP is $3,460 and Champion Toyota (Houston) shows a discounted price of $2,630.
Champion ToyotaWorld

Good luck with your project; we're looking forward to hearing about your progress.

In my experience 100% markup seems to be roughly the going rate for auto parts at retail ... I only know this because at a couple different times in my life I was involved in restoring one vehicle or another and the guys at the parts counter (once at a dealership, once at a job shop) saw so much of me that they eventually started charging me something close to "trade" price and it was darn near half off the advertised list, and I never sensed that they were losing money on me. In neither case did I ask for that treatment (which I'm guessing wouldn't work); I just noticed at some point they weren't charging me list any more, and I never got around to complaining.

Short of making yourself so familiar in a shop that something like that happens, you probably can't expect that big a break; that 100% markup just seems to be established throughout the industry and there's not much competition on it. The exception seems to be these dealers that sell online such as through autopartspeople, which will sell the same dealer parts to the public at discounts of 15-20%, and that's still nothing to complain about on a $4000 list price.

I've tried a couple of times taking an autopartspeople quote to my local Toyota dealer to ask if they'd like to match it, and so far they've never been interested. The brick and mortar dealership is able to do enough business at the 100% markup that it doesn't break their heart to see me walk out and order online, and it doesn't break my heart to do it.

If anything, I'd guess that the appearance of the discounted online dealers probably reduces the likelihood that a brick-and-mortar dealer would now ever put me on a trade-price list as happened in the past. The dealers won't see the same loyalty from customers as when the alternative didn't exist, and customers may just get used to consistent smaller discounts from the online sources, rather than spending a boatload at full price with one local source and then getting larger subsequent discounts by virtue of the relationship. The net effect might be a wash, it just all gets less personal, which I guess is the general trend of things.

-Chap