Who has done their recall?

...and what would motivate them to do a frivolous recall?

 

Today I was driving a lil harder than I have been since the recall. Maybe it's just me but when in power mode & I step on it, the power isn't there like it use to be.

Has anybody else experienced this yet?

 

That would stink. Reduced Hybrid drive to protect the inverter so now the car is a turd? That would be a safety issue trying to merge into traffic on a freeway or pulling out on a busy street where your expected to give her hell or get your nice person run over. If this turns out to be true, then Toyota should have designed a more robust inverter that could handle the drive requirements of the Hybrid system and have the ability to double that current flow just so those components and solder joints would not have a possibility of failing under normal loads.

Mike

 

Mine failed last year at 70,000 miles!?!?!

It was sent off to Toyota UK HQ for analysis so I'm wondering if this recall is due to findings on these early failed inverters?

 

Yes but it still seems to build up - just slower. But it certainly isn't there for that initial surge like it was.

 

This is not your average transistor solder joint. The transistors in question are very high power; they come caseless as naked die (unusual) and are directly soldered to a massive, aluminum heatsink, noting that the bottom of the transistor is aluminum, too (do you know what they use for soldering aluminum? I don't.); then some very serious wide bond wires are attached, and the whole assembly, including the pile of other massive transistors that actually power the electric motors, are covered with clear goo and sealed into the bottom of the inverter. This is likely built in a clean room with people in bunny suits, you bet.

The heat sink itself is radiator-cooled with a coolant flowing through it. The Toyota letter to the NHTSA says that there were cracks found under the big boost transistors, with the occasional one falling off as a result, resulting in limp mode (if one were lucky) and a complete stoppage of the inverter because of arcs and sparks (if one were not lucky).

My take on this: The resistance from the tranny to the heat sink, both thermal and electrical, is normally very low. The whole inverter assembly, including the transistors, appear to be instrumented to a fare-thee-well, with voltage, current, and temperature sensors all over. Note that the boost transistors actually come in pairs for additional current capacity. A 5% change in the resistance of one transistor over another probably blows the factory testing spec out of the water, and can be easily detected (assuming the transistors have current monitors) by the low-value (good) transistor hogging the current; further, at a specified load and all that the current through the transistors, heat rise, voltage, and such probably has factory specifications that aren't really supposed to degrade much over lifetime.

The cracks that Toyota is talking about appear to be horizontal, not vertical.

All of this makes me think that it won't take much of a crack to make things detectable, so I'm giving Toyota the benefit of a doubt on this one.

KBeck.

 

Anyone got pictures of the inverter with the potting compound removed? I'd like to see the components.

Mike

 

Here you go:

From another thread: Picture_Of_Inverter_Innards

They reference a Department of Energy document that has tons of data on the Gen III power plant.

KBeck

 

That's a very interesting read ! It certainly set my mind to ease, knowing that the diagnostic is pretty much difinitive and is easily detectable. The disconcerting aspect of this whole thing is that Toyota is just now finding this problem three or for years into production of the 3rd Generation design. I would guess, those with higher mileage on their cars would be more at risk for failure.

 

Took mine in but when they tried doing it, my 12V was too weak to power their computer….and now i have a corrosion problem on my + terminal after 2 years and 39k miles….

 

Wonder if the Camry Hybrid inverter is having the same issues? What about the Lexus CT? I understand they turned up the wick to get more performance out of the same drivetrain as the Prius. It has to be suffering from inverter failures unless that car has a more robust inverter which in my opinion the Prius should have come with it or the recall should be replacing our weak inverter with a higher capacity inverter...

Mike

 

My guess: Toyota's between a s**t and a sweat try to find as many of these defective units before they stranded behind the proverbial fan. With 1.6 million affected cars, this would be curtains for them if the Government made them replace the inverters due to safety issues. I also think that the PR damage will be significant. I feel that this issue is more serious than Toyota would lead us to believe.

Now, I ask. "What will be YOUR next car ?"

 

Me been thinking real hard now that I bought a Kia Soul and found out the excellent build quality and incredible dealership experience. I suppose the Prius inverter is designed with special components so it would be difficult to reverse engineer it to come out with a better aftermarket inverter.

Mike

 

overall Korean Car is good build and reliability better than pre 2010
I would bought Korean Car again before picked Prius, but the price was not attractive today.
Hyundai brand was not known well, when I bough Tiburon in 2002. the price was extra ordinary where everything included with very low price .

I had been 11 years with Hyundai, I was happy . my nearby Hyundai dealerships are/were sucks!!hahaha, expensive on labor cost. one dealership tried to make me to spend $3000 during yearly inspection for fixing or buy a new car from them. I just smiled and left. wasted $33 for nothing. At the end, I went to another small inspection station and passed!!!. nothing wrong with the car just some minor leaked on powersteering, some burnout LEDs, and leaked on transmission bay.

I had good dealer experience at the Atlanta Jim Ellis dealer, where I bought the car.

Alas... so many recalls on Tiburon for years . I skipped software update recall since the technician said " you do not need it" at that time.

KIA owned by Hyundai as I know.

there was a class action on Hyundai too.

 

There's been some interesting discussion of this on that other thread mentioned before. To make a long story short, the boost transistors and diodes in the Prius boost the battery voltage at 205V DC up to another hundred or so during normal operation; when flooring the gas pedal, the boost puts the voltage up to 650 or so, the better to accelerate with.

The more boost, the more heat dissipation in these boost transistors. As it happens, the other cars you mentioned have higher voltage batteries; the implication is that the boost transistors on those cars work less hard, have less heat, and, as a guess, the instantaneous differential temperature between the boost transistors and their heat sinks are less, reducing the physical stress on the connection between the transistors and the sink.

Of course, I'm the one running around yelling, "differential heating stress!" There are other engineers on that previous thread who have different hypotheses, at least one with a you-blew-it-on-the-Pulse-Width-Modulation idea. But I still like mine.

KBeck.

 

I'm glad I went back into some of the previous posts and found this. I was about to be a repetitive nice person.

Your explanation is spot on to my thinking; the higher the traction battery voltage the less stress on the electronics. In layman terms it's just like running a 120 V motor in your washing machine on 90 V's. It's going to overheat.

 

Got an Earl change today and no mention of the recall.

 

I'm surprised no one did 0-60 time before and after the recall!

 

0-60 and something like 60-90 mph tests.

Mike

 

We await your results....albeit in June or so