TPMS Light Blinking then Solid

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Sean-C, Jul 29, 2022.

  1. Sean-C

    Sean-C Junior Member

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    Hi Everyone,

    I have a 2012 Prius that's a little over 145,000 miles and it's been always gotten consistent maintenance. About a week ago my TPMS light started doing this thing where it blinks for a while and then it stays on solid.

    I checked the tire pressure and each tire is all good, and none of the tires are even close to bald.

    Also, I tried using my Obdlink LX Obd2 reader and the Tire Assistant App and it isn't getting any readings for anything for any of the 4 tires. I thought that was really odd.

    Could it be that all of the sensors died all at the same time? Or is there a main sensor that all of them work off of that could have malfunctioned or died? Is replacing the sensors or main sensor, a repair that is difficult for someone without experience to do?

    Is there a chance that the Obd2 reader that I always have connected in order to run Hybrid Assistant and cool off my HV Battery, could've triggered the light to come on? I know it's a long shot but I've seen a few people mention Obd2 readers triggering dash lights.

    Does the TPMS system participate in the Blink Codes? And if so, will that be able to tell me which sensor or sensors need to be replaced? And if not, how would I diagnose which sensors need to be replaced?

    Also, is this an issue that needs to immediately be fixed? Or is monitoring my tire pressure daily until I can afford to fix it going to be okay? (my wife and I are going to Hawaii for her sister's wedding so I'm broke as a joke right now lol. Everything I make goes towards bills and that trip for the wedding! Lolol)

    Any help is appreciated
     
    #1 Sean-C, Jul 29, 2022
    Last edited: Jul 30, 2022
  2. Tombukt2

    Tombukt2 Senior Member

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    Nope but you know the tires full The heck with it mine's been flashing for 2 years too lazy to replace the TPMS sensors haven't had the wheels off long enough with the sensors in hand The batteries are dead and one or more usually they're made by Pacific corporation you can buy them on Amazon and eBay
     
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  3. Sean-C

    Sean-C Junior Member

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    That's a big relief to hear! Especially coming from a Senior Member here on PC

    There's also this clicking sound that I started hearing today, and it sounds like it's coming from my front right wheel. It's only there under 20 mph and it's a light clicking.

    A week or two ago I drove through a road where they were doing construction and they were laying the gravel for the road. The guy told me it was okay to drive on but when I drove through the road, it sounded like stuff was shooting up under my car the whole time lol. I even had to scrape some fresh hot blacktop stuff off my wheels and. It was a huge pain! Could that have anything to do with what's going on with my TPMS?
     
  4. Sean-C

    Sean-C Junior Member

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    Sorry everyone! I was having some reception issues and my last post double posted and I'm not able to delete the duplicate post. My apologies guys.
     
    #4 Sean-C, Jul 29, 2022
    Last edited: Jul 29, 2022
  5. ChapmanF

    ChapmanF Senior Member

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  6. Grit

    Grit Senior Member

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    :ROFLMAO:
     
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  7. Sean-C

    Sean-C Junior Member

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    Thanks. I checked out the owners manual already before posting and have identified the issue as a TPMS issue. I should have stated that in my initial post, but I figured checking out the owners manual was a given before posting on Prius Chat. Similar to how going through the available threads that are already on Prius Chat is the standard before posting.

    My question was more about if the TPMS sensors work off of a main sensor or how that all works, in hopes I can diagnose the issue and identify what parts need to be replaced. But it's always nice to go through the basics just in case!

    If I had the money to just bring it in somewhere and throw cash at it until it's fixed, bringing to a local Toyota dealer might be the solution. But like most people, I'm not in the position to do that unfortunatey. I'm hoping to self diagnose the issue and identify what needs to be replaced, and ideally i'd like to be able to replace it myself if possible. I don't mind getting my hands dirty if i'm able to do the job and it saves a considerable amount of money. Or if it's an issue that won't affect the cars operation then I might just live with it and get the sensors replaced as I get the tires replaced.
     
    #7 Sean-C, Jul 30, 2022
    Last edited: Jul 30, 2022
  8. Sean-C

    Sean-C Junior Member

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    Lol I hope it isn't offensive to call someone a "Senior Member" on here. I don't mean to use it in a way that means "old" or anything like that haha. In the info below users' username there is a thing that says either "Junior" or "Senior" member. I'd like to think the "Senior" long time users on this forum have a lot of experience helping out other members on here with diagnosing and resolving issues with their Prius'
     
    #8 Sean-C, Jul 30, 2022
    Last edited: Jul 30, 2022
  9. ChapmanF

    ChapmanF Senior Member

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    You can get trouble codes from the TPMS for more detail on what it's telling you about. If you don't have a scan tool that's able to do that, you can use a short wire between the Tc and CG terminals of the car's diagnostic port, and count the blinks of the TPMS light. You can search for threads with more details of how that works.
     
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  10. PriusII&C

    PriusII&C Active Member

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    My 2012 Prius had the same issue (TPMS light blinking then solid) last Oct. I didn't do anything for a few months until I got the batteries. A couple of days after I replaced the batteries, the light went off and everything has been fine since.
     
  11. mr_guy_mann

    mr_guy_mann Senior Member

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    "Senior member" means that someone has made a certain number of posts. How helpful those posts are --- can be open to debate. Some might be considered to be more senior than others? (I certainly seem to have plenty of senior moments- so I guess I must be pretty well qualified )

    Now on to your car. As mentioned, a TPMS light that flashes then stays on indicates a fault with the system. The most common system fault is that a pressure sensor at one of the wheels has failed. Average life span for the sensor battery is about 10 years. You want to confirm this by reading codes from the TPMS ecu.

    If yours are original and one is bad then expect the others to follow. Repair would be to have a tire shop install new sensor(s) - and program/clone the ID numbers correctly.

    That said, check your tire inflation every couple weeks and you should be fine until you get things repaired. It wasn't until Ford got stupid with the Explorer tire specs (along with stupid drivers never checking their inflation) that the government HAD to step in to "protect us from ourselves".

    Posted via the PriusChat mobile app.
     
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  12. Sean-C

    Sean-C Junior Member

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    Would I need to get batteries for each sensor? Or is it one thing that gets the batteries replaced?
    What is the process of replacing the batteries? Is it something that someone can do at home?
     
  13. Sean-C

    Sean-C Junior Member

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    Luckily, I am a little bit familiar with getting the blink codes, and I now keep a wire in my glove box for this exact situation. I originally had an ABS issue and If I remember correctly, I think you walked me through getting the blink codes and helped me work out what the blink codes meant (which I appreciated greatly!! :D

    Would the blink codes be able to tell me which sensors are the issue, and/or if the receiver is the issue? Or would it just confirm whether or not the issue is sensor related and help determine what the issue is within the TPMS?

    Also, is replacing the sensors something that someone can do at home with normal household tools? Or does it require special equipment that would require taking it to a mechanic?

    I'm hoping to be able to diagnose the issue, buy the parts at a good price, and hopefully do the repair or replacement myself if possible. And if not i'm trying to do it in the most affordable way possible and I have a feeling that requires doing as much of it as I can on my own :D so your help is really appreciated, my friend!
     
    #13 Sean-C, Aug 1, 2022
    Last edited: Aug 1, 2022
  14. ChapmanF

    ChapmanF Senior Member

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    So, it works like this:

    Each transmitter has an ID number. The number is printed on the transmitter (inside the tire, where you can't see it).

    The TPMS ECU has four slots called ID1, ID2, ID3, ID4, and back in the day, somebody programmed the ID numbers of your four transmitters into those slots.

    The blink codes can tell you which slot has the problem: ID1, ID2, ID3, or ID4.

    You don't directly know which slot is the tire at which corner of the car (and that changes every time your tires are rotated). There are ways you can figure that out, say by letting air out one tire at a time, and seeing which "low pressure at IDn" blink code you get. And making a list, and changing the LF, RF, LR, RR notes on your list at every tire rotation. That way, you can look at a blink code for any slot, look it up in your list, and know which tire it is.

    These days, most tire shops have wands they can wave over the tire and learn the ID number of the transmitter inside it. It can probably tell you which one is dead, just by waving.

    But that can be a little tricky: somebody recently tried that and got good readings at all four wheels, because when the wand was near the one that wasn't transmitting, it picked up the signal from one of the others. That was only caught by noticing that the wand gizmo showed the same transmitter ID for two of the tires.

    Because the transmitter is inside the tire, a shop with tire dismount/mount equipment is needed to replace it.

    Discount Tire (where I've been buying my tires) didn't charge me anything to do that last time, when I came in with a new transmitter I had already bought and registered in the ECU, and said "please change the one in this tire here".

    On the other hand, even after I said they didn't need to, they waved their wand gizmo over all four of my tires and then plugged it into my car, where it re-registered all four to the TPMS ECU. That just ended up being the same four transmitter IDs already programmed in there, but randomly reshuffled across the four slots, so it messed up my list.
     
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  15. ASRDogman

    ASRDogman Senior Member

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    Replacing the batteries is not really easy to do. Taking the sensor apart. Scraping all the
    nasty permatex stuff, like they use on the computer boxes to weather seal them, getting the
    battery out, new one in, they re-sealing it. I watched a few video of people doing it.
    It did not look like fun! And a lot of time, to save a few dollars...