Yellow triangle and p lock issue on 2012 Prius III

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by marvingloria2011, Jan 10, 2019.

  1. marvingloria2011

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    Hello,

    So I washed my car with the temperature at around -26 C. Wiped it down at the wash, drove it home and parked it in the car port with no issues. My wife goes to pick up my son and POW! Yellow triangle with p lock issue. Car’s not going anywhere. It happened once before at work and I just kept turning it on and off will pressing on the brake and depressing the parking brake and releasing it. Somehow it fixed itself and I was able to get home. A little background. Stored the car for a bit with an intelligent battery charger hooked up directly to the battery before it happened the first time. Never happened before this. My scanguage stated the battery was roughly at around 14 volts while driving give or take last I noticed it. Took the battery out and had it tested at PistonRing and they said the battery was good. 320 CCA with 12.6 volts. Gonna put it back in today. Any advice at what to look at next? Would be greatly appreciated. Thanks
     
  2. Robertto09

    Robertto09 Junior Member

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    When the yellow triangle appear, check the codes with a scanner. You will find the answer. Good luck!!

    Posted via the PriusChat mobile app.
     
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  3. bisco

    bisco cookie crumbler

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    it just needs to dry out
     
  4. marvingloria2011

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    Good answer, bisco! Lol
     
  5. marvingloria2011

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    I did check the codes on the scan gauge and I got an old one. U0293 “no communication” from something or other.
     
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  6. bisco

    bisco cookie crumbler

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    i had the same thing happen after washing the car. i almost think getting water on the door handle sensor does it.
     
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  7. marvingloria2011

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    So, I had the battery put all night because it was too cold and too late to go back out and put it back in. I just put it back in a few minutes ago and BAM! Car is fine. No codes, no message, car goes into gear and goes back and forth. Not sure what happened. Maybe the battery was starting to freeze? But it tested fine at PistonRing. Thoughts anyone?
     
  8. marvingloria2011

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    Oh ok. I thought you were just joking. Sorry. Maybe. Since it’s fine now
     
  9. marvingloria2011

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    You know. After thinking about when it happened the first time. I washed my car when it was really cold too, right after I put it back on the road. You really think it’s the door sensor?
     
  10. bisco

    bisco cookie crumbler

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    just a guess. maybe i got some water under the hood somehow. i was washing it with the fob in my pocket, and the doors kept locking and unlocking whenever i was near them.
    definitely seemed like something was confused.
    when i went for a drive, i got the warning. after a few miles, i shut it down and restarted. it either went away then, or after a few more miles, i can't remember exactly
     
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  11. marvingloria2011

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    Yeah. Mine was doing the same thing whenever I sprayed the handles but you’re right. I do kind of remember the doors locking and unlocking by themselves now that you mentioned that
     
  12. ChapmanF

    ChapmanF Senior Member

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    I don't think there's going to be a connection found between the P lock actuator and the door handles. (The P lock actuator is a flat little motor on the transmission, that shifts it in and out of P.)

    The motor can require a fair bit of juice (it has to be built to handle even situations where you're parked on a hill and the car's weight is on the parking pawl), so one of the frequent causes for a P lock error is insufficient juice reaching that motor when it tries to unpark. And very cold temps can cut back the juice available from a battery, so maybe that is what was going on, and why it was happy when you brought your warmer battery out from indoors.
     
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  13. bisco

    bisco cookie crumbler

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    interesting. my scenario was the middle of summer with a strong 12v. hasn't happened since that carwash
     
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  14. marvingloria2011

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    I'm not sure. I pulled the battery out and started walking the 3 blocks from my house to the PistonRing. I had the battery load tested and they said the battery was good (I watched them do it as well). Tested at 12.8 volts with 320 CCA (supposed to be 325 CCA). So I'm not so sure of the warm battery theory. If the battery was weak from the cold, it should still have been weak when they load tested it, correct?
     
  15. marvingloria2011

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    In the summer? Hmm, I read some posts about a door sensor on the other posts about a P Lock issue, but I was more worried about the white relays in the engine compartment and the transmission relay behind the front glove box. I just thought about it and realized that I had washed the car both times it happened in very cold weather (below -20 C). I was really hoping it was the battery so it would be an easy fix. But maybe there's something to what ChapmanF said about a warm battery, I don't know. I'll try to start it again when I get home. The only difference now is that the car block heater is plugged in and it wasn't when it happened last time. Just glad it was nothing serious. I'm not very good at trouble shooting wiring and electronics. I don't have the patience, I'm better at swapping alternators, struts, etc.
     
  16. ChapmanF

    ChapmanF Senior Member

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    If curiosity gets the better of you, Techstream can query the transmission control ECU and read back a bunch of measurements (voltages, motor phase currents, pawl position, etc.) saved as of the most recent instant when it complained of any problem.
     
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  17. marvingloria2011

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    Thanks. I read about the techstream on one of the other post about p lock issue
     
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