Need transaxle repair '02 Prius

Sorry about the bad news. The DTCs will be of interest so please do post them. In the meantime let us assume that the transaxle is done for.

Indeed you should contact Toyota 'customer experience' at 800-331-4331. Tell the story of your long support of Toyota vehicles and that all of PriusChat awaits their reply. Might help a little bit; others have gotten Toyota to go halfsies in similar cases in the past.

You could probably find the transaxle assembly from a salvage vehicle dismantler for a lot less. Getting the installation done is another matter. For this reason (and also for a second opinion on the diagnosis), I'd be heading towards Art's indie hybrid shop in Berkeley.

If you do decide to cash out on the car, I think $4k is a more reasonable price. The CA HOV stickers would indeed convince some to put the effort into a rebuild. There is at least one rebuilding shop in Sacramento, but I have not nailed down their url or telephone. Anybody reading can help with that?

Real bad news especially from a first-time poster. I hope that PriusChat can help you find the best way to proceed.

What in the heck was that $3500 for, besides the cat?

 

Can you get the car up to say 10-20 mph, fast enough to hear the whine, and slip the car in "N" can you tell us what happens to the noise?

If the transaxle has an internal short, the noise will remain even after shifting into "N". If it is inverter related, the noise would go away after shifting into "N".

Can you record it and post a URL to the recording with the speed? We can use AudioCity and knowing your vehicle gear ratios determine if the frequency is consistent with MG2 failure.

We do need the codes.

Before taking any repair actions:

• Get a sample of the transaxle fluid, at least a cup, in a clean, dried water bottle. I need it for testing and the oil database.
• Have someone drop the transaxle pan and photograph and examine the transaxle oil pan. We need to see if there is an debris there. If you plan to drive it later, you'll need about 4.9 quarts of transaxle oil to replace what is lost when you drop the pan.
• If there is debris in the pan, please collect as much as possible in a clean container, I would like to have it too.
• What oil did they use on the previous transaxle oil change?

Thanks,
Bob Wilson

ps. Swapping in a used transaxle is expensive but but the one report I've read suggests they had subsequent failures. This is not a trivial operation since it requires swapping out the engine and transaxle as a unit.

 

Hi Ken,
Very sorry to hear about your transaxle problems. I just had my transaxle oil changed at 65K miles and I have sent my transaxle oil sample to Blackstone labs for analysis. I can't really provide any help other than to point out following:

the carpool stickers in Silicon Valley are of value that should not be underestimated (but cannot be transfered). Your break even analysis should factor this in.

Another point to factor in is the price of gas. If you believe the price of gas will drop to $4/gallon, the value of the prius will probably stay about the same. If the price of gas increases to $5/gallon, you may be underestimating the value of your Prius. If the price of gas increases to $6/gallon, you may be greatly underestimating your Prius.

Regards
Dave

 

Hi Ken,

P0302 means misfire detected on the second cylinder (pp. DI-67, Repair Manual Vol. 1) The ambiguity group, "Open or short in engine wire; Connector connection; Vacuum hose connection; Ignition system; Injector; Fuel pressure; Manifold absolute pressure sensor; Engine coolant temp. sensor; Compression pressure; Value clearance; Valve taiming; ECM; PVC piping."

P3120: "HV Transaxle Malfunction"
P3120 has subcodes for motor and generator magnetism reductions. Other errors include, "shaft damaged; generator locked; torque limiter sliding planetary gear locked; motor resolver inter-phase short; open or short in motor resolver; motor resolver inter-phase short; open or short in motor resolver circuit; GND short in motor temperature; open B+ in motor temperature sensor; and the same for the generator."

Is it possible the engine compartment might have been exposed to water, say cleaning? Regardless, there appears to be a common thread suggesting a connector might be loose too.

Did the problem(s) come on suddenly or over time?

Can or did the service department read out the sub-codes? These give more details about the specific failure mode(s).

It rules out the inverter since when you go into "N", the inverter remains passive, not passing any power about. This is bad because it suggests the problem is inside the transaxle/engine area and that becomes expensive quickly.

Getting the sound let's us evaluate part of what is going on. However, it is not critical in this case.

We have two motor/generators in the transaxle. The smaller one couples to the engine as starter and part of the CVT function. MG2 is the larger one that couples to the drive wheels. If the wheels are turning, MG2 is turning.

I agree, "expense."

That is the correct oil for this model.

Yes, it is risky since we don't know what the other transaxle has gone through. It makes sense to try and have the connectors re-seated without trying to raise expectations. Sometimes it works (rarely) but the rolling testing in "N" suggests something worse. Still, re-seating the connectors is fairly cheap.

Bob Wilson

 

Hi Ken,

One of your questions was whether it is worthwhile to spend $6,200 to install a new transaxle. If your figure of $7K blue book is correct, then that repair is not worthwhile. However, the CA carpool stickers still have substantial value and their use allows you to save 30 minutes each weekday, a big plus. Hence my guess is that the $7K number may be increased to $9K+. In that case it might be barely worthwhile to go ahead with the repair.

I agree that you can continue to drive the car as-is for a while. The worst that will happen is that the car will stall and refuse to restart.

Regarding DTC P0302, usually an engine misfire is due to an igniter problem or a spark plug problem. It could be that some water entered cylinder #2 spark plug well, causing corrosion, a high voltage leak, etc. In any event this should be a relatively low cost problem to resolve if the problem returns.

I note that you've recently replaced the catalytic converter and the 12V battery. If you decide to replace the transaxle, please note that other expensive parts could easily fail in the near future, including the traction battery, the electric steering gear, and the MFD.

Your best bet would be to get some financial assistance from Toyota for the transaxle replacement. In the past it was not unheard of for Toyota to offer the part at a 50% discount. However, the auto companies are struggling financially and Toyota's budget for post-warranty assistance may be smaller now.

The big question is whether your car is going to become a money pit, or whether with a new transaxle the car will run reliably for a long period of time. Unfortunately there is no way to predict in advance which outcome will occur.

 

Hi Ken,

This is consistent with an internal winding short. It does get worse.

The subcodes help us understand the details of the failure mechanism. However, I suspect an internal winding short that will only get worse over time.

The only road hazard would be if a wheel bearing were failing. However, these don't 'throw a code.' Everything you've described is consistent with an internal failure of MG2 ... a winding short. Just start to carry a six-pack of water and sunscreen in the trunk.

I think you need to start making some hard decisions:

• another car (losing the commuter sticker)
• repair vs. other car price
• risks of other system failures

If you were near Art's Automotive in San Francisco, I would recommend taking it there; getting their estimate; and deciding. Perhaps some of our California owners might have other 3d party shops to recommend.

I would like a generous sample of your transaxle oil. I have a small amount from one other failed transaxle and really need more for my experimental uses. I would also like a photo of the transaxle pan contents and the contents if available.

Bob Wilson

ps. A transaxle from a flooded Prius might be a good option.

 

If you have the tools and the means, you may want to consider parting out the car (at least the easy stuff) or selling it on Ebay as-is. It's INSANE what cars are selling for these days. I've seen cars with major problems still sell for $4000-$5000, and that's without carpool stickers. I don't want to get your hopes up about getting some decent money back, but if I were you, I'd at least keep an eye on eBay and watch what cars are selling for.

If you wanted to part the car out yourself, I'd be interested in the catalytic converter.

 

Hi Ken,

Congratulations on getting the discount; $3,900 is much better than $6,200.

I do not think that it is possible to predict the remaining life expectancy of the traction battery. When the battery on my 2001 failed (at ~60K miles) there was no advance warning.

What price do you think you can get if you were to sell the car today?

If your traction battery were to fail, it might be possible to buy a salvage battery for ~$1K or so. However you would have to locate an independent mechanic to install it for you.

 

Good job on the discount. I suggest you mail letters of gratitude to the various levels of Toyota Inc. Praising them for their unequalled support for the Prius community.

It won't help you at all, but perhaps will help the next one who experiences a major post-warranty problem.

Personally I would lose no sleep over the HV battery lifespan, but to be sure, Patrick has had very different experiences in that area.

 

One little tidbit I might add. a notable number of 2001 Prius's (including mine) have had their HV battery changed. After 2001, there is a real reduction in the number of reported battery failures/replacements.

 

Have you owned the car since new? If not, have you asked the dealer what other service history there is? If any other work was done at any service history, it will be in the national database. You can just call a dealer service center, give them your VIN, and they can look up the history to see if anything else major has already been done. In the case of my 2002, I found out the battery had been replaced at 85k by the recall.

From my perspective, every car has it's problems. The Prius has it's own unique set of problems, but in my opinion, I don't see it as being any worse than any other Toyota. Toyota, overall, I see has having a much higher quality than most any other manufacturer. In other words, I think the Prius is a very reliable car. Yes, it has some expensive problems, but so does every other car. It also has a lot less problems than other cars. It does not eat head gaskets, it does not chew up transmissions, or go through brakes/rotors.

On the other hand, if you are contemplating selling the car, now is definitely the time to do it because of gas prices and the demand for the car causing high selling prices. An '01-'03 Prius can easily go for 10k-13k on eBay alone. I saw a 2001 with 168k and the check engine light on (catalytic converter) and it still sold for almost 8k. If your intent is to sell this Prius only to buy another one, then you are just going to end up paying a premium on the replacement car anyway.

 

One transaxle failure mode is a progressive, winding short. This is the same as a shorted secondary and in simple terms, it is drawing power from the permanent magnet rotor all the time it spins. The power it draws heats the local windings, which fails more windings over time. There is no inverter involvement.

Inverter is out of the loop.

"MG2" is motor generator 2, the larger of the two motor generators in the transaxle. The other one, MG1, handles balancing the engine torque and makes the CVT work.

I think you've underestimated the effort. It is a lot of work.

We don't know what causes the initial short to occur. Once it starts, it only gets worse. So looking at the oil testing results let's us understand some of what might have contributed to the problem.

It is the official type but I have a different opinion based upon a wear pattern I'm seeing. These are hypothesis but without a statistically valid set of oil tests, they remain speculations.

This is a personal question and you have to weight it against your situation. Understand that I will always respect the individual's choice because "you're the one who has to live with the consequences."

GOOD LUCK!
Bob Wilson

 

I, too, have received bad news about a transaxle code - but it was coincident with a leaky battery that was fixed and replaced under warranty. When the leaky battery was fixed, there were two other codes - one corresponding to the Transmission (P3120) and another one which I can't remember associated with the engine computer. On the suspicion that it might be an electrical glitch associated with the battery problem, all codes were reset and the battery was replaced. However, a few days later, the master alarm came back on, and the dealer (of whom I've been a loyal customer for 10 years dating back to my previous car which was also a Toyota - a Camry) is saying that code P3120 with information code 250 is being reset *without* the code on the engine computer, causing the master alarm to light up. The recommended fix is to replace the trans-axle assembly to the tune of $5300, parts and labor inclusive.

The car drives fine, with no new noises, sounds, or behaviors, other than the master alarm with a temporary high temp light that went out while driving, which I found odd since if it was a temperature problem in the transmission, it would need to not be turning or in gear to cool down.

The dealer has not done any diagnostics on the car other than read the codes. They haven't tested the transmission fluid, or checked electrical connections for proper resistance to the thermal sensor, etc.

Any ideas what could be going on here? Could it be a sensor problem and the actual transmission is OK? Could the battery problem have caused a power surge/brown-out that led to a faulty sensor in the transmission, or could a faulty transmission have caused the battery to overload? The car has just under 85,000 miles on it, and has given me no problems to date, other than a warranty-covered steering rack-and-pinion replacement about 4 years ago.

I have an HOV sticker on the car, and don't want to give it up since I live near Los Angeles. The dealer is contacting Toyota with this particular situation and I can live without my car while they do this, but I want to hang on to my Gen 1 Prius if at all possible, but the fact that a battery code, transmission code, and engine code all set at the same time seems to be a bit fishy to me that they are "unrelated" as the dealer is claiming.

Please advice, and thanks in advance.

-Erik

 

Welcome to PriusChat esbailey. Sorry your first post was about a problem.

It seems unlikely that we can figure out at a distance if these problems are linked. You might wish to get a second opinion from another Toyota shop on the status of the inverter/transaxle. If you do that be sure to give them a full history of the earlier work.

In such cases it is always desirable to confirm that the inverter coolant level is correct and that its pump is performing correctly. Put the car in 'ready' and 'P' and set the foot brake. Lift the hood and identify the inverter coolant reservoir. It is centered, high and near the firewall. Translucent white plastic, black cap, filled with red or pink. The liquid in side should be flowing turbulently and at a distinctly higher level (about 1/2 inch higher) towards the front of the car.

If it is not so, the system is low on fluid or air-locked and those need to be corrected before any substantial driving.

Might not be that at all, but all Prius drivers ought to know how to do this simple health check. The high&low levels would be reversed starting with 2004 model year Prius (a reminder for visitors to this thread).

It is well that the local shop and Toyota Inc are discussing this, but based on some experience with these matters it would also help if you call Toyota at 1-800-331-4331. Open a case file and tell them the full history. It also couldn't hurt if during these telephone calls (you'll be making a polite but persistent pest of yourself) you also mention that this is a matter of discussion at Prius Chat and under the eyes of thousands of Toyota customers and potential customers. They know who we are Tell them how delighted you'd be to report a happy outcome to this situation here.

Tell them how pleased you were getting the earlier steering and battery problems corrected as well. In other words, lay it on thick. Skip the part about a possibly fishy linkage between 2 problems. You have one problem now, and you very much hope that Toyota will act in their typical exemplary fashion and lend a hand.

BTW did you ever have the free replacement of the crankshaft angle sensor? At least some 2002s are on the list for this.