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08 with red master triangle, brake, and vsc warning lights

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Tecarrows11, Jul 26, 2016.

  1. Tecarrows11

    Tecarrows11 New Member

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    Looking for some help here. I was driving down the highway today and the brakes light (!), vsc, and master red triangle warning lights came on, along with a car with an ! in it on the main display screen. There is no noticeable difference in noise, mpg, or breaking performance. From reading through previous forums a bad 12v battery seems to be a common problem. Mine was replaced ~8 months ago. About 2 weeks ago the serpentine belt snapped and the car was drove ~2 miles to my home where I replaced it along with the bad water pump and also the thermostat. Could that have caused my current problem. 130k miles on the car
     

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  2. Tecarrows11

    Tecarrows11 New Member

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    Edit:
    The check engine light is from a bad oxygen sensor. I have the part ordered, but am waiting on shipping. Also when the car was let sit for 2 hours the brake and vsc light were off when restarted, but the red master warning light stayed on. After about 15 min of driving the brakes and vsc lights came back on.
     
  3. JC91006

    JC91006 Senior Member

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    Probably bad inverter pump or brake actuator. You need to read the codes
     
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  4. andrewclaus

    andrewclaus Active Member

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    I'm guessing the CEL has been on for a while then, and it could have been "masking" another DTC. We're guessing without the full list codes, as read by a Toyota scanner.

    The inverter pump is a good guess, though. Did you change inverter coolant when you did the engine coolant? How confident are you that you completely bled the engine coolant loop?

    How many miles?
     
  5. Tecarrows11

    Tecarrows11 New Member

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    I did not replace the inverter coolant when I replaced the engine coolant. I'm 95% sure the coolant loop was bled completely. The car has 130k miles on it. Around 400 -500 miles since the water pump replacement.
     
  6. Tecarrows11

    Tecarrows11 New Member

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    UPDATE:
    I bought a mini-vci and the codes that came up are below. Does anything need replaced other than the oxygen sensor and inverter pump?
     

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  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That would be a good start.

    In addition, the engine coolant temperature sensor may need to be replaced - it may have been damaged when the engine overheated previously. Start with the first two items, clear the DTC, and then see if DTC P0117 returns. If it does, you can use Mini VCI to see what engine coolant temp is being read by the sensor. The engine coolant temp reading is probably substantially higher than the temp that the engine actually is at (you can use a handheld infrared instant thermometer to determine the cylinder head temperature.)

    You can also test the wiring by disconnecting the sensor connector to see if the engine temp as reported by Mini VCI drops down to -40 degrees C. If it does, the wiring is good.