Inverter pump?

That sound points to the 3 way coolant valve, which also lights up the check engine light. Code p1121

 

Did you clear the code after retrieving it? If not, the code could still be stored.

If it is the three way valve it's not difficult nor expensive to replace. The difficult part of the job is bleeding the coolant system after the valve has been changed. Again, not impossible it just takes some time and some effort.

You can rule the inverter coolant pump in or out by observing the narrow expansion tank adjacent to the inverter for turbulence with the car in the ready position. Remove the black cap and if the coolant is swirling inside the expansion tank with the car in Ready mode your inverter pump is fine.

 

The three way valve is tied to the ICE cooling system, correct? Should I drain as much coolant and replace with new? What about the transaxle coolant, should I drain that and replace with new?

 

M, I did see the coolant moving around... wasn't very brisk or anything, just a light moving/swirling of the coolant. Stick with the three way valve? If i'm doing the three way valve, should i drain the transaxle coolant and replace system with all new coolant?

 

Stick with the 3-way valve if you seen coolant moving. The ICE/3-way valve is a separate cooling loop from the inverter. No need to drain the inverter unless you wnat fresh coolant in that system as well whichisn't a bad idea but you do not have to do that as part of this repair. I'd say do one at a time.

Yes you will need to drain the other coolant loop. Others have tried to pinch off the hoses some with success others with a coolant mess on their hands. Here's a vid for inspiration.

There are other Youtube vids of the same R&R by others just look around.

 

M, thank you very much! I just picked up my three way valve from Toyota dealer(i get wholesale pricing) and a gallon of 50/50 coolant. I'll do the three way valve first, then at my next oil change i'll do the inverter coolant. It's never been changed and i'm at 214k miles.

 

Engine loop is close to 2 gal. Inverter loop is close to 1 gal.

10yrs/150K miles is when the fisrt drani fill of both loops is to occur. Thereafter, evey 5yr/50K mile for both loops.

 

At least pick up a Lisle no spill funnel it will aid in the refilling of coolant. And if you have an air compressor consider an Airlift. The inverter coolant change is way easier than the ICE/3-way valve coolant loop.

Here's a video of an Airlift in action.

 

I bought the AirLift from Amazon but didn't buy it until after I changed the coolant in my 2008 Prius. I did use it on the Inverter coolant change and it works as advertised, no bleeding. It puts a vacuum on the cooling system and holds it for 20 seconds checking for leaks. It you then open the valve and the coolant gets sucked into the cooling system. I used it on my 1999 Plymouth Prowler when I changed it's coolant and it is another car that is a pain to bleed the air out of. I was told this is the way they put coolant in the vehicles at the factory.


http://www.amazon.com/UView-550000-Airlift-Cooling-Checker/dp/B0002SRH5G/ref=sr_1_2?ie=UTF8&qid=1519344453&sr=8-2&keywords=UVIEW+550500

 

The drawback of the economynAirLift is you CAN NOT move it slightly, once the air is drawn out, b/c the vaccum will be lost/diminished. Vaccum is needed to suck in the new coolant.

If you are confident you will be able to not move the tool, once vaccum is created, then you will be fine. Worse case, you mess up and learn. But, this will require you to redrain the loop you were working on, and recreate vaccum.

The times I've done drain and then filled w/ my AirLift, I still had to check the radiator when COLD, and top off. I guess the AirLift gets, say 90%, of the air out. This sure beats the traditional way w/o the AirLift.

 

It is important to get a good seal and keep it with the Air Lift. I always try to make one draw out of a clean 5 gallon bucket. It worked great on the inverter coolant.

 

The airlift you linked, does that one have all the connections needed for the Prius? Is that the one you'd recommend?

 

It comes with different adapters that will seal the radiator so you don't have to hold it and one that is just a cone shaped affair that you just push down on and hold it by hand, I have used it both ways. I didn't use it on the Prius engine coolant change but did on the inverter and it will suck a gallon of coolant into a car in as little as 30 seconds. I bought it because I have several cars needing coolant changes and so far have used it on three.

http://www.youtube.com/watch?v=vwUHkee-ovw