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Tire pressure sensor question

Discussion in 'Prius c Main Forum' started by thefyn, Nov 5, 2024 at 10:15 AM.

  1. thefyn

    thefyn Junior Member

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    My prius C 3 (15" wheels if that matters re replacment) tire pressure light is orange constantly despite pressure being OK.

    Is there a replacment I can buy for each wheel for my local garage to install as I'm hours away from a Toyota dealership? I read that the batteries fail around this time and you can't replace them. (Is that true btw?)
     
  2. BiomedO1

    BiomedO1 Senior Member

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    just go to Rockauto and look them up. pretty generic and won't last as long as the OEM's, IMHO.

    Batteries may be replace, but you'll have to destroy part of the housing - then refill, silicon glue-in the new batteries. It's time consuming, but it can be diy. Most will just replace and reprogram new one and be back on the road within an hour.

    Hope this helps...
     
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  3. ChapmanF

    ChapmanF Senior Member

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    Is the light just solid orange all the time, or does it blink for a minute when you first start the car, then go solid?

    Blink-then-solid is the usual indication for a system problem, like a pooped-out battery. Plain solid is the usual indication for actual low pressure.

    The batteries may poop out "around" this time, but the variation can be pretty wide. On my car, the first of the four to poop out was a couple years ago. I had another one stop working this summer, but I think that was damage by Walmart mounting a tire, not natural death. The other two are still going strong.

    So there might be no great advantage to changing all four, compared to just the one that's probably out right now. It's not the kind of job where you save much labor time by doing them together ... to do one, you have to remove, dismount, remount, and reinstall one tire, and to do four you have to do all that four times. Raising the car is about the only labor you save by combining the jobs.

    Your friendly tire shop probably has a handy wand that can show which one has pooped out.
     
  4. JohnnyPR

    JohnnyPR Member

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    Replacing and reprogramming is a better option indeed. A neighbor took his new 2018 F150 Ranger for a road trip and had a similar TPMS warning. The previous owner installed new nittos, method wheels, and brake pads, and at least one of the sensors was damaged by the shop. Less than two hours job at a local shop and he's back on the trail.
     
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  5. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I’m a broken record on this, but feel obligated to note: if money is tight, you can just ignore them. At least until the next time you’re getting new tires. Check your pressures regularly too.
     
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  6. BiomedO1

    BiomedO1 Senior Member

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    Or you can just go old school analog.:love: You'll still need to walk around the car.....:whistle: Pre-flight check for the non-mechanically inclined family members. Got them on all my non-TPMS cars.
    upload_2024-11-6_8-39-51.jpeg
     
    #6 BiomedO1, Nov 6, 2024 at 11:40 AM
    Last edited: Nov 6, 2024 at 11:49 AM
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  7. Danno5060

    Danno5060 Active Member

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    I have a 2011 Gen 2. It's probably a similar sensor. About a year ago, the light on the dash would flash for a bit every time I turned the car on, then it would go to on steady. This is an indication of a problem with one of the sensors.

    If your light goes to on steady, without flashing, it's triggered the pressure alarm and not the sensor alarm. Since mine was a sensor alarm, I went to a tire shop when the alarm was active (it only failed on cold days) and they couldn't scan the right front tire. That's when I knew what sensor was malfunctioning.

    A friend of mine has an OBD2 scanner that can talk to the tire monitor ECU, and I was able to read the tire pressures. I forget what else was I could read, the sensor battery voltages, temperatures too. I think I was also able to see that one of the sensors wasn't reading at this point. The car doesn't specify which tire is malfunctioning, just what sensor ID.

    I looked, and I suppose it's theoretically possible to replace the batteries. There's a clear bulge in the sensor where the battery lives, but mine were encased in some sort of epoxy and weren't really made to be changed.

    I got a set of 4 OEM sensors from eBay for around $60 (yeah, I know but they're working. New from Toyota were more than what I paid, for only one sensor).

    I had my new sensors installed when I did the yearly summer-to-winter tire swap, so I look at the installation as free since the shop didn't charge for replacing them when changing out the tires. Before going to the tire shop I used my friend's OBD2 tool to change the sensor ID numbers that the car was looking for, and verified the new sensors were talking (I was able to put the sensors next to the wheels, and when I changed the IDs, I got somewhere next to 0 PSI (the sensors were in a box next to the tires, not in the tires at that point) and somewhere near the same temperature as well (which also made sense with what the temperature outside the car was at the time).

    I could probably have gotten some aftermarket sensors, which are programmed using the shop's sensor tool to match the IDs the car is looking for. I read that people weren't having the best of luck with the aftermarket sensors holding up, so I opted for the OEMs.

    There's also a TPMS reset button under the dash. It's not altogether straightforward what it resets, since the system works differently than the original that monitored the relative tire rotations, but maybe it's worth a try. Make sure your tire pressures are all within spec first (check the spare pressure too. It probably doesn't have a sensor in it, but it can't hurt to check the pressure). You may have to hold the button till the alarm light starts flashing.
     
    #7 Danno5060, Nov 6, 2024 at 3:57 PM
    Last edited: Nov 6, 2024 at 4:13 PM
  8. bat4255

    bat4255 2017 Prius v #2 and 2008 Gen II #2

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    We have learned to ignore the TPS on our 08. We went old school and just do a "pre-flight" (check the tries) weekly. The cost to replace the sensors is just stupid.
     
  9. rjparker

    rjparker Tu Humilde Sirviente

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    Sensors can be replaced for $100 total if you buy them yourself and shop small tire repair places for installation. No balancing is needed and you could get a rotation in the deal.

    Pressures can drop overnight when the first cold front comes through. All four of mine went from 35/33 psi to about 26 psi. They looked fine because they were all the same.

    The TPMS light came on and ten minutes later I adjusted all four to the door sticker 35/33.

    Otherwise you are wearing them fast and losing mpg at best and could lose a tire at worse. Which is a safety issue.

    A nail in a tire can happen anytime. I have had at least four of these turn on the TPMS light on the v.

    It amazes me some will tear their egr systems down over a two day period but opt to fly blind on their tire pressures.

    ps: Tire pressure sensors are usually an one time repair in your ownership while other maintenance is preformed over and over again.
     
    #9 rjparker, Nov 6, 2024 at 4:42 PM
    Last edited: Nov 6, 2024 at 4:57 PM
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  10. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    We ignore the TPMS light for about 5 months each year, with our snows on separate rims. Check pressures regularly.

    Appreciate it's off-topic; just food for thought.
     
  11. rjparker

    rjparker Tu Humilde Sirviente

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    Little known tidbit: The TPMS ecu has registers for two sets of different sensor ids.

    The second snow tire strategy uses a set of Autel Mx sensors which can clone your summer tire sensors. No ecu write needed. About $120 for four but requires an Autel TS508wf to clone existing and read existing.

    IMG_6647.jpeg

    Autel tool and 4 cloneable sensors $275 ($220 at Autozone with discount code TIME4AUTUMN)
     
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