Hell -Red Triangle after coolant inverter replacement

1. You need to be clear about whether you replaced the engine coolant or the inverter/transaxle coolant.
2. If you replaced the inverter/transaxle coolant then the engine does not need to be on when bleeding the air out, while the cabin heater has nothing to do with the system - so it does not matter what temperature the cabin heater is set at.
3. Since you say that a gallon of coolant came out, I assume that you drained the engine coolant.
4. If my #3 assumption is correct, did you refill the engine radiator? It is not sufficient just to fill the reservoir tank.
5. If my #3 assumption is incorrect, do you see fluid turbulence in the inverter coolant reservoir?

 

Have you checked the engine oil level, while on level ground?

Have you checked the coolant level in the radiator itself? Air got introduced into the engine cooling loop somehow, despite you believing otherwise.

To drain the coolant for the inverter/transaxle, you just removed the inverter coolant bolt on the transaxle?
You did NOT open the valve on the CHRS (Coolant Heat Recovery Storage) tank?

 

P1121 is not in the inverter coolant loop. If you replaced that valve and drained all the coolant, that would be the engine coolant that was drained. You did not drain the inverter coolant

 

JC caught it. Replacement of the 3-Way coolant control valve, due to DTC P1121, effects the engine cooling loop. You still have air in the engine loop. Time to get the factory service manual so you will know what you are doing. You thought you knew and refernced You Tube videos, only to learn otherwise. 2 day subscription to Toyota TIS (Technical Information System) is only $15 for a 2 business day subscription. Lots of info about accessing TIS is readily available by searching.

It sounds like you corrrectly drained and filled the inverter cooling loop.

 

The coolant that was drained, was drained from the transaxle (think transmission). You just performed a drain and fill of the Inverter cooling loop. You also seem to have correctly bleed the air out of this loop.


The engine and inverter cooling loop are two separate and independent loops. Even the radiator was built for this on the Gen2 Prius: two independent cooling loops within one radiator.


Replacing the 3-way coolant control valve affects the engine cooling loop, as the picture illustrates.

Given that you just performed a drain & fill of the inverter, you probably should just do a drain & fill for the engine coolant loop. If you do not already know, the coolant drain & fill interval is 10years/100K miles on the factory fill (think new car). Then it is 5years/50K miles, unless you choose otherwise.

And you should be concerned. You are calling things by the wrong names and allude to the same refill spot for two different cooling systems. Did you refill the Inverter loop at the Inverter reservoir? You know that small opaque bottle, in the middle of the car, to the left (if facing the windshield) of the big silver square thing (the Inverter) that has a Toyota logo and says "Hybrid Synergy Drive"?

Are you aware that the radiator overflow bottle is under the black plastic engine cover, in front of the radiator, left of center? After changing the 3-way coolant control valve, where did you add the replacement coolant?

QUOTE="CarmanNJ, post: 2423224, member: 126030"]

• What did I do wrong?[/QUOTE]

Its hard to guess b/c you are calling things by the wrong name and addlude to the same refill spot for TWO different cooling system loops.

1) Getting the Factory Service Manual would be an excellent start.
Toyota - New Subscription
You will be better off getting a two (business) day subscription to Toyota TIS (Technical Information System), for $15. You will have access to the factory manual. It is an invaluable investment, just like getting the hacked Techstream and mini VCI. Pretty much any and all of your questions on "How do I ...," will be answered. Good diagrams, torque values, diagnosis codes, decent step by step instructions, trouble shooting trees; far superior to Haynes/Chilton. Supposedly if you start your subscription on a Friday (say 5PM), it will end on Monday (4:59PM). Copies of the manual are supposedly floating around in cyberspace. $15 is a small price to pay to for an authentic copy; who knows if the copies floating around have not been maliciously altered or are complete.

This person discovered how to save the CHM format into a PDF format. Toyota TIS download tips | PriusChat More power to you if you know how to preserve the CHM format.

2) Sadly, you seem disinterested in going the factory manual route. Questions would have been answered and your knowledge enhanced.

Continue the Internet search for answers/videos.

This link may be useful for you: Changing engine coolant | PriusChat
It will likely require some note taking as some posts will not be relevant to your needs.

3) Acquire Techstream and mini VCI. A very useful tool.