Need Advice - Problem Light - Triangle/Exclamation Point Symbol & High Coolant Temp on '09 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by makenakate, Oct 15, 2013.

  1. makenakate

    makenakate New Member

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    Hi all,

    I have a 2009 Prius Touring with about 55,000 miles on it. Had it regularly serviced last Thursday at the Toyota dealer/service center, and they said it needed to have the coolant flow control valve replaced due to sticking - so I agreed and they did it under warranty.

    On Friday afternoon, I was driving out to the desert and about 50 miles into my trip, the red triangle with exclamation point symbol appeared on my dash, and the word "Problem" beeped on my screen. Then it went off, and then back on a few minutes later. Then it happened again and the high coolant temperature warning light came on the screen...and then went away. I turned off the A/C and opened the hood to check for steam or heat, but there was nothing. Since I was far from my destination, I called the closest Toyota service center and promptly drove there, but the light was off when I arrived. They said they checked everything out and ran the codes, but nothing came up.

    When driving home on Sunday, the car did the same thing - Problem Triangle and High Coolant Temperature warning light on and off for varying amounts of time and with no correlation to how fast I was driving or how hard the engine was working. I left the A/C off the entire time.

    Today, the car did the same thing after driving for about 10 miles. I brought it back to my regular service center, they ran codes and checked everything out...but they cannot find anything. They said they can't determine anything with the light off, but it doesn't stay on consistently so it's nearly impossible to bring it in with the light on.

    Has this happened to anyone? Any advice on what to look for or do?
     
    #1 makenakate, Oct 15, 2013
    Benjamin13295 likes this.
  2. dorunron

    dorunron Senior Member

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    Three
    Pull the plastic cover over the radiator. When the radiator is cold, remove the cap and check the fluid level. I bet you will find it is low. They probably got air in the system when they changed the valve. Also, turn the heat on and run it at the highest fan setting with the temperature on HI. If you hear sloshing or gurgling, there too is another indication of air in the system. If it is low, take the Prius in and have them check it, purge the air from the system and refill it properly. It should all have been taken care of when they changed the valve. If it is not low on fluid, then you have a different problem.
     
    #2 dorunron, Oct 15, 2013
  3. Joe 26

    Joe 26 Member

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    Agree with above. Most likely low coolant level.
     
    #3 Joe 26, Oct 15, 2013
  4. dorunron

    dorunron Senior Member

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    There is the chance that the technician messed up completely when changing the valve by not putting the correct hose on the valve in the right place. There are three hoses. As I understand it, it is easy to hook it up wrong. Chances are you are just low on coolant. FYI, the coolant used is Toyota SLLC (Super Long Life Coolant). It is recommended that you use that as it designed for the metals used in the engine and the components. You can buy it at any Toyota dealer. It varies in cost, usually in the area of $20 per gallon. Some charge less, others more. It is also the same fluid that is used in the inverter which runs on a separate loop.
     
    #4 dorunron, Oct 15, 2013
  5. Benjamin13295

    Benjamin13295 Junior Member

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    How did you fixed the problem? Same thing happened to me
     
    #5 Benjamin13295, Aug 5, 2018
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