Inverter pump failure with no symptoms?

Try touching the pump with a finger or a rod (pencil, stick, etc), if you feel a vibration then it should be working.

 

Even if vibration indicates the pump is running, it still might not be working. If there is no discernible movement, this to me is a better indication of whether the pump is working or not.

Yes and maybe not so much luck as a series of events that have worked in your favor. If there is not a great load on the inverter then it can run quite happily. The inverter coolant circulation pump (ICCP) failure is not monitored so it will not trigger a DTC, but if the inverter gets too hot that is what triggers a DTC (P0A93 and/or C1241, maybe others) to alert you to the situation. When this happens you will be pulling over and waiting at least 20 min for the inverter to cool down so you can go again and probably sticking to 45 MPH or less.

You don't really want to run in this condition in the long term, because if the pump goes out in style and shorts out, it will blow the AM2 fuse and the dash and MFD will go out and you will be dead in the water until you isolate the ICCP and replace the AM2 fuse.

 

i don't recall a whirring noise on startup

 

You don't really want to run in this condition in the long term, because if the pump goes out in style and shorts out, it will blow the AM2 fuse and the dash and MFD will go out and you will be dead in the water until you isolate the ICCP and replace the AM2 fuse.

This x2

i don't recall a whirring noise on startup

Try just pressing the power button 2x with your foot off the brake. The ICWP should run and the rest of the car will be quiet (as long as radio and fans are off). Makes it much easier to hear the pump motor running and makes makes the ripples more obvious since there wont be vibrations from any other source.

 

thanks, i will try that

 

I have the same issue....no movement at al...what to do next..replace pump?

 

Yes, that is what you need to do. It is not a particularly difficult job.

 

I find it odd though it runs all this time without any ¨problems¨.. no warning lights no DTC...no overheating...no blown AM2 fuse ...no nothing...how is that possible..is it slowly dying..?

 

If the inverter is not taxed too hard it can cope for quite a while, especially in colder climates. Additionally, for the AM2 fuse to blow, the pump has to short and it quite often doesn't. Your situation is the proverbial "sleeping giant", so as to speak.

 

the ¨sleeping giant¨...? To expect big problems if it fails comletely..? So best fix asap?

 

Een gezegde betekenis: a disaster waiting to happen.

 

i got it right...thanks for effort in dutch..the exact translation is ¨spreekwoordelijk..¨...meaning the same as ¨gezegde..¨
thank u...

 

I just had a thought to double check the pump ,,,
i attached a hose to the bleed screw off the transaxle (...inverter/converter)...and started try to bleed the system...so put car in READY mode..fluid started moving in the hose but never made it all the way into the reservoir...i guess pump is indeed bad..i also noticed a fair amount of air bubbles...so maybe someone never ever bleeded the system...where as the pump startedfailing..?

so maybe this to is an alternative way to check your inverter coolant pump..
me i am gonna order new pump and replace this asap.
i attached picture of the hose going into the reservoir where u can clearly see where it stopped...

I love Prius Chat....! thank u all!

 

Yes, that is a better word. Dank u wel.

Just a question relating to your picture, would the coolant flow if the tubing did not loop so high above the reservoir opening? I was just wondering if maybe there is an airlock stopping the pump from actually pumping.

 

yeah I tried that already...it flows yes, but not very much fluid like a how do u say that piss trickle..?
I try to shoot a vid...

 

I get your meaning. It was just a thought, but I'm glad you already tried it.

 

I do think there´s alot of air trapped in there...to a point that the flow just stops, still no momevement in reservoir whatsoever, here´s a short clip of bleeding and the flow coming out the hose...dont know if its visible... dont know if thats normal flow...

 

The flow rate through the bleed will also depend on how 'open' you make it. On another note, I personally think it doesn't hurt to treat that pump as a 75k mile maintenance replacement item, especially if you're able to DIY the replacement.

 

yeah of course...I ´open´ it few turns till it starts to flow.....and i already ordered a new pump..not OEM though...