Gen II inverter failure

It is rare for the inverter to fail without some external cause, such as reversing battery polarity when jumpstarting the vehicle, or the inverter coolant pump failing which causes inverter overheating. So your experience is unusual.

Please post the DTC that your car logged; your repair invoice will probably show those failure codes.

 

WOW.. Sorry to hear that you were on the highway when it happened. I too have a 2004 and know that the failure of this component is inevitable. I have 68,000 miles. I have the extended warranty until Nov 2010. I am PRAYING that this part fails before then!!!

I know this is not comforting, but it IS just a part and under normal usage, I guess you got some decent life out of it. I do not think it is designed to last the life of the vehicle. Please let me know if this is incorrect.

 

What makes you say that? I don't consider a failure of mine inevitable, or even likely. As Patrick says, failure is rare without some external cause.

Failure of the inverter coolant pump, on the other hand, seems more common, to the point where he replaced his as a preventive maintenance step.

 

Although I can't confirm otherwise, why would Toyota do that? We know that the batteries were designed to last the life of the car. Why not the inverter?

My inverter currently has 177,800 miles on it. My original inverter coolant is still nice and pink. I believe that a failure at 80k is an anomaly.

 

An inverter is a big box of electronics. Much of it is standard technology, but the high power switching electronics (Insulated Gate Bipolar Transistors, IGBTs) are a little more custom. Generally solid-state electronics are very reliable, but any time they get too hot they can break. Normally it's actually the (typically) fine wires leading from the sliver of silicon to the pins in the package that melt. As a result it's imperative that electronics are kept cool. The IGBTs naturally generate heat because of the vast amount of power they handle, that's why they're liquid-cooled through an independent coolant loop. (The engine coolant would be too hot; efficient fuel control starts at 73°C which is enough to break some components.)

However, assembly problems do occur where a solder joint isn't formed correctly, known as a dry joint. Over time, with vibration, this poor joint, which is brittle, can break completely or become an intermittent connection. Electronics manufacturers try to eliminate dry joints and to check boards with inspection, but they can be missed - there are thousands of joints to check. Toyota have had dry joint problems with the MFD.

 

Stuff happens, toyautoman. Ask Toyota USA to give you a break on the replacement.

Hobbit's work shows that the early MFD failures were caused by the incorrect design of the footprint for a particular surface mount connector.

 

Mike,
Have you had a chance to read "The Prius that Shook the World" by Hideshi Itazaki? It has a whole chapter devoted to the IGBT development. I think you might enjoy.