I have a 07 Prius that just displayed check engine light. Code found was P1121 which is a coolant flow malfunction according to research I did. Checked coolant for inverter and it is moving very nicely. Inverter is very hot! Information I found says it is a coolant inverter valve. Also, prior to this issue when I stopped the car the sound from the engine (pump antifreeze/coolant into storage tank) was odd. Snapping sounds and not the usual buzzing sound. Anyone every change one of these flow valves? Thanks guys.
How exactly are you doing this research? P1121 is about a coolant flow control valve for the engine cooling system, and has nothing to do with the inverter cooling system. Toyota Service Information and Where To Find It | PriusChat
While I may agree checking the inverter cooling system isn't perfect, it also isn't that far off when you're new to it all... Why not just tell OP that the sensor in the 3-way coolant valve has gone bad and it happens in almost every really old gen2 Prius and it's fairly easy to replace and there's lots of cheap after market ones that runs just as good as OEM: http://www.ebay.com/itm/394097566363 And you might also help OP by letting them know they can go years without fixing this problem and it won't be any concern other than a slight loss in MPG when engine is running cold.
Just looking at threads and what is on the internet. Having written that, my inverter was hot after I drove the car today. Maybe I have multiple issues. I will look at that coolant control valve. I have never replaced one of those so I will see what happens. Thanks for the information.
