After two occurrences of DTC 3130 following 50-60-mile trips, I narrowed the problem down to the inverter coolant pump. There was very little, if any discernible turbulence in the coolant reservoir, a tell-tale sign of a problem. I ordered a new pump, G9020-47022 (without bracket, as the original can be re-used), last Tuesday, UPS delivered it on Wednesday, and the dealer service installed it today. (The fast delivery was due to my close proximity to the Parts Geek warehouse in NJ.) In addition to lack of turbulence in the reservoir, the inverter cover will feel very warm to the touch. This is not normal! See this link, especially Condition A and Repair Procedure A: https://www.underhoodservice.com/tech-tip-don-t-be-shocked-if-prius-owners-lose-their-cool/. Fortunately, the problem was addressed before the inverter/converter self-destructed, saving this owner a bunch of $$. The new pump cost $150, and labor added another $300 (job price--car was in the shop about two hours). Thankfully, new coolant pump is still available. The brand I got is Aisan (that's the spelling, not "Asian"). So, folks, regularly check that reservoir, and avoid costly repairs!
And both of those spellings are different from Aisin, the company that makes Toyota's pump. Are you sure yours says "Aisan"? Edit: I noticed later that this is the Gen 1 forum. When I said "the company that makes Toyota's pump", I was thinking of the Gen 3 (and later) variable-speed engine and inverter coolant pumps. It turns out (see below) that Aisin and Aisan are both real Japanese companies that make auto parts, and maybe (for all I know) Aisan could have always been the one that made the gen 1 and maybe gen 2 single-speed inverter coolant pumps.
Fascinating! What connection exists, if any, between the Japanese company Aisin that produces automotive parts as part of the Toyota group of companies, and a company Aisan that appears to also operate in the automotive component space? Gemini seems to believe (as most do here) that Aisin is the one that produces the electric engine pumps used on gen 3 and later (and, I think, also the variable-speed inverter coolant pumps used on those same models). Of course, Gemini might believe that because so many believe it here.... I guess it's quite possible Aisan made the single-speed inverter coolant pumps for gen 1 and maybe gen 2....
Well, it says "AISAN" on the box that the pump came in.There is no manufacturer mark on the actual pump itself. Outwardly, at least, the replacement looks identical to the OE pump. "A rose by any other name...." Speaking of W.S., the latest theory is that Shakespeare did not write those plays and poems; it was somebody else with the same name.
