Help broken down on hwy right now

Apparently your inverter coolant pump has failed. You can confirm this by looking for fluid turbulence in the coolant reservoir when the Prius is READY. Lack of turbulence means no pump action.

If you continue to drive the car you run some risk of permanently damaging the inverter. Obviously, towing the car is your best solution.

However if you are concerned about the cost of a tow and the ambient temperature in your area is very cool right now, you might try stopping at a store and buying a bag of ice. Place that on top of the inverter cover, with hopes that the ice and water dripping out of the bag will help to keep the inverter assembly cool. You might try returning to El Paso so that you can find a Toyota dealer there; but I would not suggest you attempt to drive 350 miles without proper inverter cooling.

 

The inverter coolant reservoir is mounted on the side of the inverter, in the space between the engine and the inverter. If you see no turbulence in the fluid when the Prius is READY, then the inverter coolant pump is not running.

I suggest you keep your speed down, and keep the AC compressor off if you can, to reduce the electrical load on the inverter.

 

The Prius diagnostic system has no idea whether the pump is running. It only knows when the inverter overheats. Therefore the DTC is not going to be logged until the inverter overheats again.

I agree that Precision Toyota in Tucson is a good place to entrust service of your Prius; however you are taking a substantial risk by trying to drive across southern Arizona via I-10 in relatively warm weather.

 

I really think you should try an ice bag on your inverter and check/replace it periodically, if you are intent on making the drive to Tucson today. And, be ready for the possibility that you may be stuck on the side of I-10, somewhere in the middle of the desert.

I do not know whether the temp numbers you are retrieving can be relied upon. I am more concerned about the inverter overheating, than the transaxle overheating. However if either overheats and fails, you will be looking at a healthy four-digit repair bill.