ALL MUST Read this, PLEASE Make sticky!

sticky; doneski

 

and, thank you jim!

 

.super common problem.

 

The content-free title is a very poor title for any thread, let alone a Sticky.thread.

I believe the thread creator can still edit the Title to make it more descriptive.

 

45 minutes driven with no coolant pump

 

45 minutes driven with no inverter cooling water pump......

MUCH different than driving with no engine coolant pump.

I would guess there are currently dozens or even hundreds of gen 2 Prii currently driving around with a failed/failing inverter cooling water pump. If your typical drive is <45 mph or only a short distance, you would never know it failed unless it pops the AM2 fuse. The inverter will protect itself if it starts getting too hot.

 

Yes there are various levels of circulation quality of the inverter coolant circuit. Based on pump health and I believe contamination of the fluid itself,

I noticed at around 35000 miles on my bought new 07 the fluid circulation looked poor. It barely showed any
Movement at all in the tank. It was rippling a little. After I changed the fluid with new SLLC and added a bottle of Redline Water Wetter the circulation was intense. It looks like it boiling. And has been ever since.

My working good pump was replaced years later under the factory tsb. Around 70000 miles and after pump was replaced I replaced the fluid again and added water wetter.

I did some temp tests before and after fluid change using infrared thermometer and noticed the inverter was running about 10 degrees cooler after fluid change, I also got a really big mileage bump.
The inverter runs very cool and can’t remember exact numbers but it’s about 75 degrees cooler than the engine.

I also noticed a huge spike in inverter temp after the car is turned off just from the underhood heat and trans/engine heat sink.

I believe like everything else under the hood the inverter coolant loop fluid suffers from break in contamination and that affects pump circulation. It sees a huge cross section of pure aluminum heatsink and is contaminated by that. At 35000 miles the inverter fluid in clear glass looked very contaminated.

 

No, you can't. I've tried. But if you want to change it, you can click the "report" button and ask a moderator to change it. I wouldn't do that on a whim because it wouldn't be nice to the moderator, but if the title really needs it, they are just as interested as you are in seeing that it's not misleading or otherwise inappropriate.

 

I am not sure why OP thinks this is a design flaw. I think this is a way to protect the very expensive electronics in the inverter/converter. If the fuse blows and you know why, then disabling this safety feature is not wise. It depends on the circumstances, of course, but I would not drive around with a failed inverter coolant pump. I would try to have it delivered to me, but I am glad everything worked out without a major problem. Still, this is not a flaw, just a failure of an electric part and the shut down is actually a very good design to prevent the inverter from frying itself. Yes, being stranded in the middle of nowhere is very unpleasant, but cars do fail sometimes. It's better to manage the failure than just grenade a very expensive part (inverter). If you were in a non-hybrid and the water pump or a hose failed and you lost all the coolant, what would you do? Most cars would just let you drive until your engine overheats and is damaged beyond reasonable repair.

 

VF,

The problem is that when the pump shorts and blows the AM2 fuse, it totally kills the car, dash goes black, etc. When you're in the middle of traffic, this creates a massive suction of the driver seat cushion into areas where it should never go. I can't think of any good reason why the pump should be powered from a fuse that affects the car in such a way. When opportunity arises, I plan to install a 7.5-10 amp inline fuse right at the pump in all 3 of our family Gen 2's.

A mechanical failure of the pump has no effect whatsoever, other than the inverter will protect itself if needed by going to limp mode if it gets too warm/hot. Why should an electrical failure be any different?

 

Ah, I see now. So the inverter has another way of protecting itself from overheating? Yes, this does not sound like a good design, in that case.

 

Just had this happen to me will update with some more details making the 45 minute drive with VSC light and red triangle lol lifesaver

 

Safely arrived to mechanic after 50 mile 50 minute drive. After 20 min check engine and orange circle with exclamation point came on.

Just to verify: the fix is to replace the inverter water pump part CARQUEST T1192?

$40-ish Amazon ordered