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Triangle of doom

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PristinePrius, Nov 2, 2013.

  1. PristinePrius

    PristinePrius Junior Member

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    Triangle of doom came on while coming home last night. Showed the little thermastat on screen. Checked the coolant this morning which was severely low. Topped off. Took for a test drive and it CME back on. The codes also pulled yesterday were P1116 & P1121. Posted last night and every ones responses were to check antifreeze which was done previously stated. Any advice?
     
    #1 PristinePrius, Nov 2, 2013
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Check the engine coolant level in the radiator again when the radiator cap is cool, to make sure the radiator is totally full.
    2. Turn on the cabin heater, temperature set to MAX HEAT, fan speed at high, and make sure you don't hear any air bubbling around.
    3. If 1 and 2 are good, then visit your Toyota dealer to have the DTC confirmed, which will result in replacement of the engine coolant valve.
     
    #2 Patrick Wong, Nov 2, 2013
  3. PristinePrius

    PristinePrius Junior Member

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    When test drove, we turned on the heater and it didn't even get warm. Had been driving already for about 5 minutes on a very warm day. After the heater was turned off, the triangle came on about 2-3 minutes after that.
     
    #3 PristinePrius, Nov 2, 2013
  4. PristinePrius

    PristinePrius Junior Member

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    Another thing, when the triangle came on, I heard something like a light rattling noise, but seemed to go away when we were cruising or not using the pedal.
     
    #4 PristinePrius, Nov 2, 2013
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    So have you checked the radiator coolant level again, after the cap is cool to the touch? You may find the level is low now.

    If the level is good and you don't hear air bubbling, then the coolant valve is probably stuck so that coolant is not getting to the cabin heater core, more evidence the engine coolant valve has failed and needs to be replaced.
     
    #5 Patrick Wong, Nov 2, 2013
  6. PristinePrius

    PristinePrius Junior Member

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    So being that the coolant was extremely extremely low, we bought the stuff and refilled it (into the black coolant reservoir cap- right ride of oil dipstick.) I checked it after we been home awhile and it's still filled. I have also checked the other engine coolant and its still the same -full. What else do I need to do? Do I need to pour the antifreeze into the radiator (silver cap) itself?
     
    #6 PristinePrius, Nov 2, 2013
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, absolutely, the fluid level in the radiator itself needs to be checked, since it was low. Remove the silver cap and look inside. The fluid level must be at the very top of the radiator neck.

    If not, fill the radiator fully, replace the cap, drive the car until the engine heats up, then turn off the car, let the engine cool down, check the fluid, add as needed, repeat this process until the fluid remains totally full when you check after the engine is cold.

    There may be air in the system which will become evident as the engine goes through heating and cooling cycles.

    Should you find the radiator level is low when you check, you can speed up the heat/cool cycle process by filling the coolant, replacing the radiator cap, then revving up the engine for 10 minutes or more, while parked on the driveway. Leave the gear selector in P, and just floor the accelerator pedal. The engine won't spin very fast but that will help to warm up the engine, open the engine thermostat, and promote fluid circulation.

    To determine that the engine thermostat is open, feel the radiator hose coming from the engine and connected to the passenger-side of the radiator. If the hose is not hot then the thermostat is still closed. Keep working at revving the engine until the thermostat opens.

    Its also easier to run the engine when parked on the driveway, than to have to actually drive the car around.
     
    #7 Patrick Wong, Nov 2, 2013
  8. PristinePrius

    PristinePrius Junior Member

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    Thank you, will do this first thing in the morning. Will follow up.
     
    #8 PristinePrius, Nov 2, 2013
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