Inverter Coolant Pump TIP!

Well, if the inverter coolant pump really has failed, then you're just ignoring the problem that the pump needs to be replaced. Although the inverter may not be heating up enough for the hybrid vehicle ECU to log a DTC, the inverter is still running hotter than it needs to.

If you DIY, a replacement pump costs ~$90. If you must pay the dealer for this to be done you might be charged $300-$400. That's a reasonable investment to protect the inverter which costs $3.6K and the transaxle which costs $3.5K (not including labor required to install.)

 

Replace the pump ASAP. Otherwise you are waiting for the inverter to die and that'll cost you thousands.

So this is one warning before the inverter would die. Consider yourself lucky because for some they never got the error code.

 

No. Wrong assumption. RE: As far as taxing the inverter the inverter on my 07 runs very cool even in dead of summer. Living in Florida the car's AC has been on max cool all day everyday year round since I bought the car. I have a temp sensor on my Inverter and it does heat soak when you shut the car off after coming off a 90 degree day in stop and go and will shoot up briefly to say 120 F but for the most part will run around 90F on a super hot day. Very good cooling system. One day we had a 100 degree and stuck in stop and go. Traction battery was not happy but the Inverter was no problem. Never ever a code.

When a Prius throws a code its not kidding.

As stated your pump is probably bad and not pumping 100% and your cooking your inverter. You don't notice because its winter.
You can prove it. Just buy a Laser Temp like this one:

FLUKE 62 MINI IR THERMOMETER - eBay (item 110485319308 end time Jan-28-10 10:55:10 PST)

and check out the chassis on the inverter for temp. It a very handy
tool.
Sears sells one for $20 too which worked good for me for about 2 years. Its good to get a baseline temp on things like this.

BTW, have you ever had the Inverter coolant replaced?

 

A working inverter pump should be able to keep the inverter at an acceptable temperature while blasting the A/C and driving around in the highest ambient temps you can ever expect to experience. The OP's pump really is dead or dying and needs to be replaced!

 

If you DIY I'd get a repair manual and follow usbseawolf's guide on youtube to gain confidence:
[ame=http://www.youtube.com/watch?v=-yf6eCeV4M8]YouTube - 2006 Prius Inverter Coolant Change[/ame]

 

I'm a DIYer, so spending $90 on a pump is MUCH better of an option than a $3400 inverter. But then, my car will be under warranty for a few more years.

With a vehicle like the Prius, I don't think I'd ignore codes and 'chance it'. Too many components are VERY expensive.

 

If I get an IR thermometer... where exactly do I aim it to get the best inverter temp read?

Doing a long road trip to Florida this coming month and would probably be interesting to see temp values. Our '05 just went over 70K miles.

And when should we change the inverter cooling fluid?

 

Since Toyota recently issued an LSC to replace the inverter coolant pump at no charge, there currently is no reason for an owner to spend any money on this particular repair.
http://priuschat.com/forums/gen-ii-...ump-dealer-letter-technical-instructions.html

 

I replaced the pump last spring. I got a check engine light and the dealer mis-diagnosed the problem as the battery cooling fan. Thanks to Patricks help, I figured out the pump was the problem and replaced it myself in about 50 min. When I bought the pump at the dealership I asked at the service department how much they would charge to replace it. They quoted me three hours. Funny how when I'm paying it's 3 hours and when Toyota is paying the bill it's 1.2 hours.