One owner 2006 Toyota Prius with new hv battery. Now getting code P1150 only after car sits overnight. No code entire day with starts,stops, restarts. Just replaced the chs water controller, sensor, pump and changed antifreeze. Bled system by using the vacuum method. I believe the code is erroneous but would like to correct. Thanks for your thoughts!
I think you may be correct but not sure what to do next. I bought the vacuum device after several attempts at bleeding with the bleed valve open back to the funnel in the neck and manually running the pump. Guess I could try that some more. It seems erroneous because the code doesn't show until 5 min and 3 miles down the road. If the sensor didn't "see" water at start up, seems it should show up then. If I sit and idle without moving, no code. The wiring looks okay and no wreck damage in that area.
Whenever I do this service, I tend not to drain the thermos cooler. I drain everything else and it gets about 1.5 gallons out. Bleeding air is much easier and I never have issues. Yes it's not all the coolant in the car, but 1.5 gallons every 30,000 miles should be pretty good.
So I guess you have not needed to replace the parts I have because you have to drain the thermos tank at least partially to replace the sensor,pump, and controller.
