Did I cook my brand new HV battery

when the inverter pump isn't working, the software puts the car in limp mode as temps climb, to protect the battery and inverter

 

ok. You're talking about multiple separate systems.

The inverter cooling water pump provides coolant flow through the inverter and transaxle. It has no control valve and is basically just on or off. Has flow or doesn't have flow. An abnormal high temperature in that loop (inverter) will initially make the AC turn off (the AC compressor is powered by the inverter), if that doesn't unload the inverter enough to eliminate the high temp, then the car will code P0A93 and go to limp mode. The HV battery has no fingers in the inverter cooling loop, so will be completely unaffected either way. The HV battery is cooled by air, circulated by that round white fan behind the passenger side trim panels in the hatch area.

The coolant control valve is in the engine cooling loop, which is 100% independent from the inverter cooling loop. It works with the Coolant Storage Tank and its pump to store hot coolant for later use. The control valve basically controls direction of flow into, out of, or around the coolant storage tank (thermos) hiding in the front driver side quarter panel. This system preserves hot coolant in the thermos to help with future warmups.

Basically....

 

AC turning off (but not outright failing) is a common symptom of a failed inverter pump. I wouldn't worry about damage to the battery pack. Remote chance the inverter might have sustained some damage that might cause it to fail some point in the future. Even if it does go eventually there are lots of these inverters available for not much in junk yards - they hardly ever fail, and with no demand and high supply, the price stays low.

 

Getting hot is not the same as overheating.

The reason the inverter sheds load is to protect itself.

 

You say OEM Battery so you had a Toyota dealer install a brand new Toyota battery?

What did they charge please?

You never mentioned how many miles on the car. How many miles on the car? With a new hybrid battery you should be getting at least 50 mpg's falling off a log.

Be aware when the dealer replaces the inverter coolant pump they usually do not change the inverter fluid. They just clamp both hoses pull the pump out slide a new one in. Especially if it was done under warranty which that alone blows my mind the car is 18 years old. So something is whacky here.

So the car probably has the original 18 years old inverter coolant which is not good. It may clog the inverter cooling channels as the inverter has a huge cross section of heat sink with tiny circulation channels. It requires clean good condition coolant. A clogged Inverter cooling loop requires the Inverter be replaced.

And if its a if its a high mileage car with 150K+ miles on it it may eat alot of engine oil. It needs to monitored closely to see how much. If you don't one day the check engine light may start flashing that may mean the engine ran out of oil and can destroy the engine. We have seen many of those on this site.

People sell there bought new G2's after years of ownership for 3 main reasons:

1---Needs a hybrid battery
2---Its a little oil eating monster.
3---Both.

 

Over heating is the Achilles heel of this car. There's no temp gauge on the dash so if you over heat the engine you will get a check engine light but by then its usually too late as the aluminum head may warp. Really stupid design. The water temp should be monitored by an outboard scan gauge after a water pump replacement to confirm your bleed job worked and no air lock and its not over heating because getting all the air out of the engine coolant loop is very very difficult on this car and an airlock could damage the engine. The problem is the CHRS bottle that stores hot water for a cold engine restart cannot be bled. That bottle will trap air bubbles in the cyl head. You have to outboard cycle that bottle at its relay to pass that airlock along.. You will know if you have an airlock issue you may hear water sloshing or gurgling sounds under the dash. If you do stop driving the car till it is bled properly or you may toast the engine.
Hundreds of posts on how to bleed the car.

Ok so you have a real OEM hybrid battery you should be getting much better mileage I suspect an inverter coolant issue you are running too hot.The Inverter is the heart and soul of the car. With the car in READY take the cap off the Inverter coolant reservoir. The coolant in that plastic tank should look like its boiling real good movement. If its just sitting there the pump is not flowing and you have no inverter cooling. Not good at all.

And the reason rain water is hitting the top of the engine is the water dam at the bottom of the windshield is probably clogged by leaves and not draining water out like it should. The wiper arms need to come off and the dam removed and flushed out. A working dam should have strong water flow behind both front wheels. Bet the car lives outside.

 

You really need to look at where that water is coming from.

Water in the sparkplug tubes usually is the seal along the wiper tray is damaged. Easily fix.

Water dripping down to your feet might be a windshield leak.

Water in the trunk can be from a few places. Search PriusChat for Leaking in the hatch battery well. It can be a bit of a job but ultimately not too difficult.

Read the thread, before you go on one of your rants. This is about the inverter coolant loop, not the engine coolant loop.

If you really want a temp gauge, well, there are apps for that.

 

Well, yes, but an OBD2 dongle has to be left attached at all times. That isn't something I want to do because I don't trust any of the consumer grade dongles not to eventually do something dreadful to the bus while I'm driving. The controllers in a modern car have been designed not to fail in such a way that they interfere with the data pathways, but I have zero confidence that consumer grade OBD2 dongles are built that way. I'm OK driving for a short time with one plugged in for diagnostic purposes, but otherwise, no.

That said, adding a temperature sensor by other means is kind of a PITA. Here is one example on a 3rd Generation Prius for the ICE coolant loop:

Too much to expect an actual temperature gauge these days, but Toyota could have had a "run time diagnostic" mode on the MFD, to show this sort of information (engine temp, inverter temp, RPM, and so forth.) The data is available, all they needed for this was some code running in the MFD.

 

did you clean the battery fan and intake vent?

you could try cleaning the throttle body, are you sure about the miles?

 

have you checked for dragging brakes?

 

congrats!