I've done a lot of reading through these threads and was able to diagnose, purchase, and replace the failed inverter water pump in my Prius one month ago (August 23 2019, to be exact). I had the master warning light, the VSC light, the brake light, and the check engine light all come on, along with the A/C failing and blowing only warm air. I took it into the Toyota dealership, and they said I had a million things wrong. I replaced both the accessory battery and the inverter water pump myself and everything seemed to be working after that. I drove from Las Vegas to SLC and have not had any problems driving around town since. Well, I just had the exact same thing happen today while on a 1.5 hour drive. At 45 min in, all the lights came on and the A/C failed, and I drove over to Pep Boys and the guy said I had codes for the catalytic converter and the inverter water pump. He said he's seen those two problems together before so he thought it was the catalytic converter causing it and that I should "work" my Prius by accelerating full force and using a couple tanks of premium gasoline in order to clean it out. That seemed like a strange suggestion to me, but whatever. He reset the warnings, and I was off. 5 minutes later, all the warnings came on again. I decided to finish the other 40 minutes left to get to my brother's house since he has tools and know-how to fix this kind of stuff (although no Prius/hybrid experience unfortunately). I arrived okay, just without any A/C. He has an OBD and I got the code P0A93 only. No catalytic converter code. However, the check engine light has come on and off intermittently for 2 years now and every time I've had it checked, they said it was the catalytic converter warning code. So it might just be off temporarily. When I turn on the Prius to READY, now only the master warning triangle and the check engine lights turn on, and I don't see any turbulence in the coolant reservoir. The coolant level is at or slightly above the FULL line (When I replaced the inverter pump, I also replaced all the coolant with the Prestone 50/50 kind). Does anyone know what is going on? If the pump is bad, I guess I can replace it again, but that seems like a band-aid solution to me. Something is causing the pump to fail in the first place. Any ideas? I would really appreciate your help - I'm a poor graduate student with an unemployed wife and 4-month-old baby and inherited this car from my dad, without any other financial help from my parents. I'm in a lot of debt, and can really only do the cheapest solution possible. Thanks everyone!