How to change inverter coolant 4th gen

No, engine coolant side - sorry, guess I didn't mention that. I thought the heater core thing, gave it away.

The inverter coolant pump will fire as soon as you place the car into ready mode. So be ready to add more coolant as it pumps the air bubbles out of the system.

 

Yep easiest just to do both coolant and invertor coolant at the same time since they are both due...you do have to remove the big shield underneath for access.

Looking at my spreadsheet, took under 2 gallons of Toyota Super Long Life. After filling, you do have to run in Maintenance Mode until you hear the electric cooling fan on the radiator come on twice...takes quite a while (around 20-minutes or so)

The Car Care Nut, years ago, showed these neat radiator fill funnels and they come with adaptors and have fit on all our vehicles.

I change out radiator and inverter coolant every 5-years or 50,000 miles, whichever comes first. (My 2021 went over 50,000 earlier this year....there's two coolant drain cocks....white and yellow....open up radiator to help drain it out faster but it's not fast.

 

I may have actually done “Ready” (flakey memory, hey it was about a month back ), but made dang sure to just let it go about 5 seconds, avoid engine start up.