Red Triangle, no codes again

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Nance459, Jan 24, 2023.

  1. Nance459

    Nance459 Junior Member

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    Hi all. I was driving 2006 Prius this weekend and hit the brakes hard when I saw tree in my lane, the Red Triangle came on along with the low pressure tire light. I pulled over and made sure the high voltage traction battery interlock switch was engaged (I had an issue in August and moving it cleared the RTOD then, there weren't any codes then either, but it wouldn't start for a long time) after doing this and this and the low pressure tire light cleared and RTOD stayed on. I was afraid to turn the car off the off to see it it cleared the RTOD because we were in no-where land and no cell service etc. I didn't have my obdII with me to see if any codes and the display seemed to show the battery was working ok and decided to continue home. I didn't have any codes, and the RTOD cleared after turning car back on, so, can the high voltage traction battery interlock switch go bad and jiggle out of place? BTW The traction battery was replaced 2 years ago.
     
  2. BiomedO1

    BiomedO1 Active Member

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    Sounds like something in the traction battery pack is definitely loose. Whomever rebuilt that battery, may have missed a lock washer or didn't torque down a connector properly - and it worked it's way loose. Fun fact is that those cables carry a lot of current and heat up. If something isn't torqued down correctly or a lock washer isn't put back into place - the constant heating and cooling will push stuff apart.
    I haven't been reading about any interlock switches failing. I would take the car back to whomever replaced that traction battery pack and get it reinspected for loose connections.

    Good Luck...
     
  3. Nance459

    Nance459 Junior Member

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    Thanks so much for answering! I will have it checked out further! Nance
     
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  4. Tombukt2

    Tombukt2 Senior Member

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    One of the first things to do when something like this happens slamming on the brakes is pull over and check your oil I've noticed in my '09 when I'm getting low on oil it is burning some or using some not a lot but when it's down and I step on the brakes or get the car suspension on the settled the red triangle will flash. And that's the first thing I do is I'll pull over at a gas station or whatever is convenient let it sit a minute while I talk on the phone or do whatever I do get out check the oil if it's low top it off that will kind of stop that. Could it be in the hybrid battery possibly but I would think taking power away from something or a wire moving and causing the red triangle to come on The car would be seeing something and would try to set a communication code or something?. But I have noticed three or four times I've let it happen to see and in about 4 weeks maybe five my '09 will start to get down to the tip of the oil stick and if I slam on the brakes or go around to turn with too much spirit the triangle will come on and I'll barely catch it sometimes I'll barely see it out of a corner of my eye because it won't be on but for a second maybe a few at best and then if the next convenient time I pull over and check my oil properly and it'll be down at the tip of the stick I fill it up and I don't see that triangle for 5 weeks or close to it technically it's not worth trying to fix the engine using a little oil at close to 400,000 mi is not an issue we're not running any oil that's very costly
     
  5. mr_guy_mann

    mr_guy_mann Senior Member

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    Check the oil level.

    Then I would scan the car for codes. Even if the master warning light is off, whatever ecu involved should keep any codes as "history" for some time. What are you using as a scantool?

    Posted via the PriusChat mobile app.
     
  6. Nance459

    Nance459 Junior Member

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    Thanks, my oil is full, checked, also it has been changed every 3-4k miles since we bought it in '06, no leaks doesn't burn oil.
     
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  7. Nance459

    Nance459 Junior Member

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    oil full, recently changed. I tested with both veepeak obdII and Dr Prius and with Elm 327 with Torque app. I know there are better at dealership, etc, but with my husband working so much OT he doesn't want me driving it without him able to pick me up if anything goes wrong. Nance
     
  8. Tombukt2

    Tombukt2 Senior Member

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    Then like the other say it's probably some corrosion on a connection somewhere in the HV battery's a good place to be looking because pretty much there aren't a lot of connections in too many other places and that'll cause this Don't know the battery history but the car sounds like it's in good shape it's not burning any oil not doing anything out of the ordinary there should be some stored codes because that light came on You have to have a reasonable tool to get them.
     
  9. pasadena_commut

    pasadena_commut Active Member

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    Your car is not yet having any relevant symptoms, but it might be a good idea to inspect the brake master cylinder. When cars get old the plastic reservoir on the master cylinder can become fragile, and it may crack on a really hard stop. I had that happen on a Mazda 323 once. It not only cracked, it immediately leaked so badly that the brakes were completely gone a block later.
     
  10. Nance459

    Nance459 Junior Member

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    Battery installed 2 years ago, getting ready to access traction battery area today. Not comfortable with place that installed it as they returned vehicle with 12v battery not connected tightly causing it to not start years ago, i fixed connections properly and never had an issue after the forum told me where to look. crossing fingers i can solve this.
     
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  11. Nance459

    Nance459 Junior Member

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    No leaks at all, thanks for the suggestion.
     
  12. Nance459

    Nance459 Junior Member

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    I jusst cleaned the fan and reinstalled it and ran Dr. Prius again, this time got error P0A0D, I reset the traction battery interlock switch, cleared the code, disconnected the 12v battery for 5 min and it cleared it. I still think it feels too loose though. I'm going to youtube installing the traction battery and hope I can figure it out. Thanks for all the help, wish me luck.
     
    #12 Nance459, Jan 25, 2023
    Last edited: Jan 25, 2023
  13. ChapmanF

    ChapmanF Senior Member

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    P0A0D's a pretty straightforward code. There's a safety interlock circuit that runs from the HV control ECU through some contacts in the inverter (to detect if you've taken the inverter cover off), then along to the back of the car, to two contacts beside where the orange battery service plug goes in, and the plug bridges them when it is in place and fully seated.

    So if you have a P0A0D code, the cause could be up front, if you were ever poking under the inverter cover, and otherwise, more likely than anything else, it's the orange service plug not fully seated so that it connects those two small contacts (which are visible, if you take a close look with the plug out, so you see what it has to do).

    Way less likely could be a problem with the wiring of that circuit, which would take roughly no time to sort out with an ohmmeter; there's nothing about that circuit that's complicated.
     
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  14. Nance459

    Nance459 Junior Member

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    I just cleaned the fan and reinstalled it and ran Dr. Prius again, when time got error P0A0D, I reset the traction battery interlock switch, cleared the code, disconnected the 12v battery for 5 min and it cleared it. I still think it feels too loose though, I think something not installed properly since this is the 2nd time this year, both times I re attached the interlock and it cleared it. I'm going to youtube installing the traction battery and hope I can figure it out. Thanks for all the help, wish me luck.
     
  15. bisco

    bisco cookie crumbler

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    maybe it's damaged?

    watch
     
  16. Nance459

    Nance459 Junior Member

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    That's what I was wondering when I posted this thread, don't know how, we don't even open the area where they are located, no water damage or corrosion in there? The only one that has accessed it was the place that installed the replacement batteries two years ago.
     
  17. Tombukt2

    Tombukt2 Senior Member

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    There are a bunch of videos online on the traction battery You can take the carpet and the flat plastic piece right off the top of the battery tray flip it up gain access to the traction battery If you're really slick you could take a quarter inch drive 10 mm socket with a flex and get the top of the cover off the battery pretty much while it's sitting in place and then you can have a look at bus bars nuts temperature senders wiring running to the front end control of the battery You can look at the I think it's a brown plug that plugs into the traction battery computer all this is right up in the front cover next to the relays any corrosion and nastiness needs to be cleaned up and/or replaced. I don't know where you live but I have a bunch of this stuff laying up here underneath my shed in the dry You can generally pick up this stuff from junk yards in your area that are not franchises like that have been there a long time and get it very inexpensively too You may have to look at a couple cars to find it in good condition that is possible but it's worth your trouble as you well know once the car is running and not giving any general problems it's a wonderful car to own and drive You almost can't beat it
     
  18. ChapmanF

    ChapmanF Senior Member

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    P0A0D code hasn't even got a thing to do with any of that stuff. It's about the two small contacts next to the orange service plug, and one skinny wire from there up to the inverter in front (and one to body ground), and two more contacts under the inverter cover, and a wire from there back to the HV control ECU.

    Even if there's something wrong with it (besides the orange service plug being not completely seated, which is the usual story), it's the kind of circuit that takes about as long to completely check with an ohmmeter as this took to type.

    ok, I'm a slow typist.
     
  19. Nance459

    Nance459 Junior Member

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    Thanks, so I will pull it and check it. Thanks again, Nance
     
  20. Tombukt2

    Tombukt2 Senior Member

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    This Is the plug I'm always telling people to slam into place If you haven't hurt the side of your finger sliding the plug on the last stroke downward is a good chance it's not seated at least in the three I've had this was a thing haven't I've even used to bent piece of metal with a 90 on the end of it and use that to pull it down hard I've not seen any bent pins yet or destroyed pins on the orange plug that have to made up to not get this code or whatever.
     
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