[DGD]

Interesting. I replaced 2 coolant bypass valves on 5th gen RAV4. They didn’t leak. Both of them failed resistance test.

What was the issue with the engine and did replacing the bypass valve help

 

[DGD]

Thanks for your response the info was interesting I have had no codes or messages, just seems like the heater could preform better and the engine temp never seems to reach operating levels in cooler weather. In your situation it must have been allowing flow through the heater core and affecting ac i would think. I wonder if it could restrict coolant flow in the heater core if it stays partialy closed and show no message or code? Seems like the thermostat could be my issue.