2001 Prius transmission failure

Hello,

I also have a failed 2001 Transaxle with a P3120/250 sub code, indicating a MG2 temperature sensor performance problem. Temperature of MG2 was a whooping 170°C (don't ask me about that in F) and the tranny made a whining noise when driving after the error happened the first time.

Failure reason was a faiure of the insulation of the winding of MG2.

This is the same error codes as the ones at the Arts Auto homepage.

As I am tricky I made them give me the broken tranny

Pictures can be found:

Here and Here

I doubt that the O-ring was the root cause for the failure, as the oil is mainly for the bearings and have no influence on winding temperature.

Good luck with your replacement

ciao

Floiran

 

While my daughter was driving my 2001 the transmission nearly seized up. The car was pushed by a police cruiser about 100 yards to a parking lot as it would not move. The car had about 85,000 miles at the time and the dealer said the entire hybrid drive needed replacing. Toyota stepped up and covered the parts (80% of the bill). As I purchased the car with 60K miles I cannot vouch for the various fluid changes etc.

Since this time my transmission oil changes are every 30K miles on all three Priuses. (2001, 2002, 2006). $25 for oil (0.08 cents/mile) is very cheap insurance.

 

Thanks for the good pictures. No doubt about the MG2 failure here...and that replacement was the only option. Even though you may not get a lot of direct replies, a lot of people pay attention and photos like this may help other NHW11 owners.... by further convincing that transaxial fluid replacement is a very good idea.

 

Excellent! I was able to load major sections of their database and plot out the various failure modes. I've done this for the 2001 and 2003 and you can see Toyota fixed the steering problem.



I'm sorry about the transaxle failure. I've been tracking transaxle oil to determine the wear pattern and ways to reduce internal drag. If you still have the failed transaxle, I am very interested in getting a sample. I've got one small sample from a failed transaxle but need a larger quantity and more samples.

I need about 1/2 cup saved in a polycarbonate bottle (aka., dry water bottle.) If you can get it, send me a PM and I'll send my mailing address and the oil test results later.

Bob Wilson

 

I have a 2002 Prius with 94,000 miles. I've only replaced the water pump (under warranty) and the radiator in addition to regular servicing. The transmission has just failed (although not as catastrophically as the one described here). Since I've been doing the servicing at an independent mechanic, Toyota refuses to participate in the $6000 repair. This may be the leading edge of a big problem. Has anyone else had a similar issue?

 

Could you provide more details about the transaxle failure? I'm trying to understand "not as catastrophically" as in how yours failed?

Does the car move on its own?

Are there unusual noises?

Bob Wilson

 

Same exact thing just happened with my wife's 2001 Prius. Dealer said $7000 to put in a new transmission with only 108K miles. I've been a loyal Toyota driver for years and always got 200k miles plus with no major defects. The car is still currently at the dealer and they are calling Toyota to try and get some assistance in the cost. We don't use the dealer for service because they charge way too much for everything. We have a mechanic that we trust and have used for several years. If the tranny fluid needed to be changed, he would have certainly mentioned this I'm thinking. I found some rebuilt transmissions online for as low as $950 with a 2 year warranty and no core charge(cherry-auto.com). Anyone have any input about getting one of these rebuilt trannys and does this include the right part to fix this issue?

 

Some of us are interested in failed transaxles. Good Prius friend Hobbit or some of the folks he know may be interested in the old unit. It is a VERY heavy unit and likely to be a bit messy so picking it up from the dealer is not trivial.

Bob Wilson

 

Wow, another n=1 poster with a problem. Sorry you got bit.

If you hope to get some cost sharing from Toyota, I believe it would be better to negtiate directly with Toyota 1-800-331-4331 rather than letting the shop do it. This is often successful, especially when the injured party can master the technique of polite persistence.

I don't think there is much collective experience here in full transaxle swapping, but Hobbit would be a great ally in confirming that all the necessary pieces and connectors are present and OK in the swap unit.

Physically I suppose that it would not be so very different than a conventional FWD automatic trasmission replacement. I don't know if it requires removing the engine for 'mating' and then dropping the whole thing back in. So perhaps not really difficult, but a very long list of parts to be removed and then re-installed in an appropriate sequence.

Don't forget the inverter coolant system air bubble removing steps! Good luck.

 

Engine + transaxle get lowered out the bottom - so the car needs to be raised high enough to do that, then secure the engine + transaxle on a raised transmission jack, and lower the jack.

Separate engine from transaxle, attach new transaxle, raise into car, reconnect everything, fill and bleed stuff.

Nice straightforward project. I've never done it. In fact, I've never done any car where the removal was out the bottom. Sounds like a pain, probably just because it's not what I'm used to.

Everything I've seen tells me the transaxle is very heavy. Nothing I've seen gives an actual weight. Things suggest attaching an engine hoist to the transaxle for support while disconnecting it from the engine. I think Art's Automotive's photo essay suggests a hoist even for disassembling the transaxle itself, just to lift the MG2 side off the MG1 side. Yow.

-Chap

 

First post from a new member -- with a sudden transmission failure in an 02 Prius:

I am one of those early adopters -- bought my 2002 Prius in Sep 02, and have loved it ever since. I've been such a loud fan that my brother and sister each bought a Prius, and two weeks ago I bought another one for myself, a 2010 PIII, designating the 2002 to the use of my college-age son.

Out of concern about the new technology, I bought the largest extended warranty I could with the 2002 -- that cost me an extra $1,300 at the time. The 2002 has been maintained pretty daggone close to plan and all service (except for a few oil changes) has been done by Toyota service centers.

Here's the bad part: two days ago, as my son rolled in to Knoxville, TN, all the lights came on and the car lost power. He and some crewmates pushed it to Toyota of Knoxville, who told us that the car needs a new transmission and inverter at the impressive cost of $7,500.

Like many of you, I fully expected this car to last at least to 200k miles -- but not without some manageable problems or parts wearing out. Tires have been a problem, and I just had to replace the brakes. However, the sudden catastrophic failure of the transmission on a Toyota is hard to accept as normal. In fact, reading this entire thread and others I've found, this problem seems to be in the "defect" category.

I've opened a case at the national Toyota customer service center, and am supposed to hear from them on Monday. I do hope that the company will do the right thing and offer to share in the cost of this repair.

If not, I'm undecided whether to fix it or not. In excellent condition, it's only worth about $7,500. Does anyone have any thoughts on this?

Is there anything else I should be doing?

PS: this forum has been very helpful to me today -- thank you!

 

I can not help you in negotiations with Toyota. I'm technical and if you or your son has an interest in repairing it yourself, I could help. But clarify a couple of questions:

• You're in VA but the failed Prius is in Knoxville TN?
• Do you or anyone in the family have the tools, work space or interest in doing the work yourself?

There are very few, independent Prius mechanics but one who lives in North Carolina. I doubt if he does 'house calls' but it depends upon your interest in keeping the vehicle.

Catastrophic failures occur but it might be interesting if there were any unexpected noises or vibrations before the failure.

Bob Wilson

 

My son, a rising junior in college, took the car from VA to TN so that he could row in the US Club Nationals championships. Purely bad luck that it failed in Tennessee.

NO ONE has tools, work space, or interest in doing the work ourselves. We are completely incompetent mechanically.

Bob, on reading this thread, it's clear that you are carefully collecting information about this failure. I will ask Toyota of Knoxville to provide whatever info they got when they did their diagnostic investigation. Likewise, when he gets back tomorrow, I'll ask him about unusual sounds prior to the time when all the lights went on and the car lost power.

Thanks for your prompt reply.

 

Saw you problem today August 20, 2009. I was just told my transmission (127K miles) needs to be replaced. In May 2009 had to replace batteries, now this. How did your problem turn out? Thanks from Unhappy2001owner in San Diego

 

Well, I have not seen any post lately on this issue. A few days ago, I was driving and I noticed the engine was making a strange noise. At a stop light, the gas engine was still going. I knew something was wrong so the next day I was going to drive it to the deal to have them look at it. I didn't make it because the warning light came on and I lost what seemed to be all lower gears. I could drive it, but not very fast. I went back home and had it towed to the dealer. After two days of trying to find out what went wrong, they came back and said that Toyota is saying that it is the transmission and it will be $4500. The car has 150K on it and trade in value is $6000. I am going to try to talk to Toyota to see what they can do, but at this point, I am done with Toyota completely. First the headlight issue and now this big expense.

I had a small truck that was still running great at 210K with only having to replace the alternator.

Even it the transmission is replaced, at 150K, I know I am nearing the age of a battery replacement. So good luck to all of you Prius owners. I wish you better luck than what I had with it.

 

Good luck with getting the trans fixed. I'm really hoping that my G2 Prius doesn't end up like too many electronic gadgets: supported only while it's the newest-bestest thing. It seems to be the case with many failing Gen1s that individuals are forced to simply scrap the car due to the immense repair cost.