My 07 prius started giving a p0093 error on long trips. The first time I looked at it and cleared the code to see if it was just a fluke. It was fine while driven short distances, but on a second long trip the same code came up about 40 miles after filling up, which may or may not be coincidence. I did some more research, and some signs pointed to the inverter coolant. The car is 10 years old with 240XXX miles on it. The inverter pump and water pump was changed in the recall (2012?) When i looked at it, i could hear the inverter pump working, but the fluid was barely moving. I ordered the Toyota coolant and I just changed the coolant. I've read several threads here and have tried to bleed it several times, but no fluids are moving. I push the power button twice, but there is no noise and no movement. I had the bleed valve open when I was filling it, and could hear it gurgling and bubbling. Eventually fluid came out the bleed valve, and I closed it. Now, nothing is moving. My next step is to drain it and flush it, but I thought i'd post here first and get some better ideas. Thanks!
P0093 is not a valid Prius DTC. If you meant P0A93, that points to the inverter cooling system performance, typically resulting from a failed inverter coolant pump. It would be reasonable for you to replace the inverter coolant pump now.
That was the code that it gave, but my reader might be old. My newer reader wouldn't connect to the car, and the car has since reset the code. This was last week, and I was out of town. But that does help, thanks!
I just had to replace the inverter pump and don't think you want to drive the car very much with a bad one. This video shows the "turbulence" you should see in the coolant reservoir with the car in IG-ON mode. I replaced the part in less than an hour with a $75 OEM pump. Recommend using the tutorials on PC that involve removing the headlight. I also replaced the coolant while I was at it.
The inverter pumps on the Gen 2 and even the Gen 3's are known failure points. Even the newly redesigned pumps fail, not at an alarming rate but they fail as the originally designed ones do. The cost of a new pump and Toyota's SLLC is far less that having to hang a new or used inverter. The choice ultimately is yours. Should you choose to change the pump yourself Patrick Wong has an excellent How-To/DIY on PC documenting every step of the way. If you are more of a visual learner there are good Youtube vids of the same.
