Odd Red Triangle warning - advise needed

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dave Newbold, Apr 16, 2015.

  1. Dave Newbold

    Dave Newbold New Member

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    I'm new to Prius Chat and I'm hoping your collective wisdom might shed some light on this condition. During our long winter, my Prius 12v battery finally failed and I had it replaced by my dealer about a month ago. My wife reported seeing the red triangle warning occassionally on her commute; it would go on for about ten seconds and then disappear. I did the obvious fluid checks and nothing seemed low. The other day I saw the warning myself and the coolant icon appeared in the main display. Both the main and overflow levels were fine.
    I took my Prius into my local (and honest) mechanic and asked him to scan the error codes to help dagnose the warning. He checked all the sub system code and they were all empty. He also verified that nothing seemed physically wrong with the car; he checked for leaks, drove it, etc. He seemed to think there might be a loose connection on some sensor, but couldn't explain why there weren't any error codes in the system dump. On the way home I got the warning again. (sigh)

    Any advise? I'm not a big fan of my Toyota dealer, but I guess that is probably my next step. Has anyone experienced this before? Many thanks in advance..
     
    #1 Dave Newbold, Apr 16, 2015
  2. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    If the problem is intermittent, no technician will find it when its not there. If your coolant icon appeared, that means its likely coming from the coolant level sensor. Can you tell me what you were doing when you saw this icon? Were you turning, braking fast? If your coolant level is right at the low level of the full mark, a turn could make it go below the full level and cause this intermittent signal. The fact that it is intermittent means the sensor is working. It is likely that your coolant is shifting as your turning or braking and causing the sensor to trip momentarily then reset once you straighten out.
     
    #2 usnavystgc, Apr 16, 2015
  3. Dave Newbold

    Dave Newbold New Member

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    Thanks for the quick reply; I can't tie either the general (red triangle) or coolant icon appearence to any specific driving action - my memory is they both appear during moderate acceleration on relatively straight and level roads. Both coolent levels are full...
     
    #3 Dave Newbold, Apr 16, 2015
  4. JC91006

    JC91006 Senior Member

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    You checked the oil level correct? Did you make sure the inverter water pump was working? Open the fill cap of the inverter reservoir and when the car is "Ready", make sure there's movement/turbulence in the water.
     
    #4 JC91006, Apr 16, 2015
  5. bisco

    bisco cookie crumbler

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    check the 12v connections, especially the ground to body. how many miles on her?
     
    #5 bisco, Apr 16, 2015
  6. Dave Newbold

    Dave Newbold New Member

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    The oil level is good and the inverter water pump seems to be working just fine (nice flow in the reservoir.) Thanks.
     
    #6 Dave Newbold, Apr 17, 2015
  7. Dave Newbold

    Dave Newbold New Member

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    I have 85K miles and the new (Toyota) 12v battery connection looks good (and tests fine.) The mystery deepens...
     
    #7 Dave Newbold, Apr 17, 2015
  8. Britprius

    Britprius Senior Member

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    Are you checking the coolant level in the radiator or in the the header tank. The header tank can be full while the radiator can be low. You will need to remove the shield over the rad to check the level.

    John (Britprius)
     
    #8 Britprius, Apr 17, 2015
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  9. JC91006

    JC91006 Senior Member

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    I agree with britprius. The warning lights that goes on and off while driving is often related to fluids being low. The gen2 cars have a notorius leaking water pump, your radiator could be low
     
    #9 JC91006, Apr 17, 2015
  10. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    I second that emotion. :)
     
    #10 usnavystgc, Apr 17, 2015
  11. Dave Newbold

    Dave Newbold New Member

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    Thanks - I checked both and they are full.
     
    #11 Dave Newbold, Apr 18, 2015
  12. Dave Newbold

    Dave Newbold New Member

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    Agreed; both levels are fine and I had to replace the water pump two years ago.
     
    #12 Dave Newbold, Apr 18, 2015
  13. JC91006

    JC91006 Senior Member

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    Is there a chance you have a door that's not completely closed? Hatch?
     
    #13 JC91006, Apr 18, 2015
  14. Dave Newbold

    Dave Newbold New Member

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    Some more details and another suspicion:

    When driving during the last few weeks I would randomly hear a muted triple beep, which reminded me of the EV mode confirmation from my Coastal Electronics EV Mode hack/switch. It did not seem to correlate with any specific action, but it made me suspicious of some kind of wiring failure that was sending the computer into a tizzy. I tried to engage the EV Mode today and realized that it doesn't work anymore. I decided to disconnect the switch and re-seat its connection plug.

    I'll let you all know if that was the issue after driving it around a bit this weekend. Thanks to everyone who weighed in on this topic - it really helped me look in the right places. Wish me luck! :)
     
    #14 Dave Newbold, Apr 18, 2015
  15. Dave Newbold

    Dave Newbold New Member

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    That is possible - will double check them all.
     
    #15 Dave Newbold, Apr 18, 2015
  16. JC91006

    JC91006 Senior Member

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    A triple beep occurs when your car is in ready mode and your car door is opened and shut.
     
    #16 JC91006, Apr 18, 2015
  17. ChapmanF

    ChapmanF Senior Member

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    I hadn't noticed this until now, so now I'm curious. Does a 2005 have a coolant level sensor? Does any Prius have a coolant level sensor? I just looked at the warning displays sections of a 2005 owner's manual on techinfo (and for grins, a 2015 too) and did not see any reference to a coolant level warning. There is, of course, a coolant temperature warning.

    OP, are you sure of what light you're seeing, or does it blink too briefly to recognize? Does it happen often enough that maybe you could catch it happening while your passenger records video on a phone, and then you could grab a frame from the video showing the light?

    -Chap

    ps: It looks like the techinfo crew is getting the message that it's annoying to download manuals one corn flake at a time. The 2005 owner's manual is still in the old form of one dinky PDF per section, but the 2015 one popped up in one 644 page PDF, no muss, no fuss. Progress....
     
    #17 ChapmanF, Apr 18, 2015
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