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Pros and Cons of Stand-Alone TPMS System

Discussion in 'Gen 3 Prius Main Forum' started by PriusII&C, Feb 2, 2022.

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  1. PriusII&C

    PriusII&C Active Member

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    A few days ago the TPMS light of my 2012 Prius started turning on and staying on. At this point I have a few options: A: replacing all TPMS sensors, B: replacing all batteries DIY, C: installing a stand-alone system with external sensors, D: disabling the warning light and installing a stand-alone system with internal sensors.

    I am inclined towards option D. Many stand-alone systems provide real time tire pressure and temperature values, and are very inexpensive, especially installed DIY.

    But I have never done this before. So I'd like to get your opinion.
     
  2. xliderider

    xliderider Senior Member

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    In the same boat with my 2010 Camry.

    Amazon sells Denso TPMS sensors that are quite reasonable if you can find someone who can install them and successfully program them.

    Posted via the PriusChat mobile app.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    I was under the impression that the programmable type sensors are pretty much a push button affair and pretty easy to do maybe in tech stream. In text stream I was just trying to turn mine off and couldn't do it with a dealer text stream computer maybe I'm not doing it right. I'm tired of light tyres never low I check very often just because I'm used to motorcycles etc.
     
  4. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    E: do nothing?
     
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  5. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Be aware that disabling the built-in will definitely be a DIY; by law auto repair shops are not permitted to perform this service.

    A touch-up on @Mendel Leisk's E: I'd suggest F, do nothing to the car but get yourself a pressure gauge and set a periodic reminder to use it in your phone.
     
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  6. Tombukt2

    Tombukt2 Senior Member

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    Disabling the TPMS sensors is against the law seriously I never heard of such a thing but that's interesting I always heard it was available to do in the dealer computer I have the dealer computer that's updated with all computer updates and everything on the machine through 2021 I have no login for Toyota personally my buddy does so I can't do live updates that's why all the computer updates are downloaded and put on the machine so one generally doesn't have to get on line with Toyota but anyway I couldn't see how to just turn the TPMS system off I see the Ford TPMS sensors I guess there's not a fifth one available if you have a real spare so I have a few wheels that are from 04s or 5s that don't have TPMS they have rubber valves stems and none of the wheels communicate or put out a signal flopping those back and forth to the 09 of course has the sensor flashing and I'm sure in the original 09 wheels all the sensors are dead batteries or the light I'm going to try some universal programmables just to see what they do they're cheap enough
     
  7. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    One other thing about E:, some US States "might" fail you at inspection.
     
  8. Salamander_King

    Salamander_King Senior Member

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    One question with this option is that Can you really DIY replace internal sensors? I have seen videos of people breaking the beads of the tire and rims and replacing the TPMS sensor/valve without removing the tire from the rims. But... this can be tricky especially if you have never done it before. If the valve is not installed correctly, it can leak. If your new TPMS sensor/valve is substantially different weight than OEM sensors, then the balance will be off.

    Also, I have not used any stand-alone system with internal sensors, but I have used a stand-alone system with external sensors. If the quality of the system is similar, then don't expect them to last very long. My experience with external sensors was about 2 years max, sometimes as short as 1 winter. I would think the internal sensors are less likely damaged by the external conditions, but still don't expect them to last very long as the OEM sensors. And when one internal sensor breaks, then you will have to replace the entire system including good sensors. At least that's the way a "cheap" stand-alone TPMS works. All four sensors are hard-coded to the main display unit. You can not program individual sensors or replace just one bad sensor.

    If you really want to see the real-time tire pressure, then going with external TPMS sensors would be the easiest and least expensive. If you are going with internal sensors, either with stand-alone or ECU linked, then I would suggest waiting until the time you need to replace all four tires. At that time, you have to have the tire installed with a new valve anyway. The cost of TPMS sensor installation will be included in the tire installation.

    I don't know if it works on Gen3, but ScanGauge II can display the TPMS data in real-time reading off from the ECU. There are other apps (Carista and Tire Assistant for example), and Tech Stream which can read TPMS data via OBDII but for safety reasons, they would not allow you to read the data while the car is in motion.
     
    #8 Salamander_King, Feb 2, 2022
    Last edited: Feb 2, 2022
  9. Tombukt2

    Tombukt2 Senior Member

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    I would think if the lights out you're not going to fail and that's why I was asking if I can turn it off without ripping out the display and disabling the LED literally it's an option that I can literally live without I check my tires just as well as the TPMS setup and I'm real picky about my tire settings
     
  10. Salamander_King

    Salamander_King Senior Member

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    Not many states in the US require working TPMS as a part of the state-mandated vehicle safety inspection program. Here is the list. Only Hawaii, Rhode Island, and West Virginia require the working TPMS. IIRC, Vermont changed the law that allows non-functional TPMS (i.e. TPMS warning light is lit on the dash). The OP's state CA does not even have a safety inspection. Emission inspection yes, but not safety inspection that covers TPMS. https://en.wikipedia.org/wiki/Vehicle_inspection_in_the_United_States


    upload_2022-2-2_11-5-21.png
    Source: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=214
     
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  11. PriusII&C

    PriusII&C Active Member

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    Thank you all for your valuable opinions and information. There are quite a few choices of stand-alone TPMS system on Aliexpress website. Does anybody know if you can set different pressure warning values to different tires? Gen 3 spare tire needs 60 PSI while front and rear tires only need 35/33 PSI respectively.
     
  12. Salamander_King

    Salamander_King Senior Member

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    I have not seen any "cheap" stand-alone TPMS that has more than 4 sensors. So your question about using an extra sensor on a spare is a moot point. There are some more expensive stand-alone TPMS for RV that has more than 4 sensors, (6 are popular for RV and trailer, but I think I have seen 8 somewhere). If you want to pay extra for that RV TPMS, then yes you can set the warning pressure individually for each sensor.

    upload_2022-2-2_12-21-16.png
     
  13. PriusII&C

    PriusII&C Active Member

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    A few systems on AliExpress have the options of 4 or 5 sensors. Typically the 5 sensor systems have a screen display change between the first 4 sensors and the 5th one. The 5 sensor system is a few dollars more expensive, but still around $30. Here is an example.
     
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  14. Salamander_King

    Salamander_King Senior Member

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    Yep, this is the first time I saw 5 sensor configurations on those "cheap" external TPMS. In that case, I would expect they will have the ability to set different trigger psi for each sensor. But, as I commented above, don't expect those units to last long. I have gone through at least 5 sets of external TPMS in less than 4 years on two cars. They just do not last very long. If one sensor dies, then you basically have to buy a new entire kit.
     
  15. PriusII&C

    PriusII&C Active Member

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    How do they usually break? Display, sensor, battery?
     
  16. Salamander_King

    Salamander_King Senior Member

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    I have never used internal sensors for the stand-alone unit, so I don't know their durability. But I suspect that the quality of those internal sensors is no better than the external ones.

    For the stand-alone TPMS with external sensors, the battery does die much quicker than regular internal sensors (OEM or aftermarket) that usually last 5-7 years. It uses a lithium CR1632 button battery, and it is easy to replace. In my experience, the battery dies within a year or two. If you read the small print on the Amazon description, many states battery lasts only up to 1 year anyway. For the external sensor, if it is just a dead battery, then the replacement is easy. For internal sensors, this can be a major headache if you have to separate the tire from the rim to replace the battery annually.

    But I have found many dead external sensors do not come back to life with a change of new battery. For my climate, road salt does havoc on the wheel and protruding external sensors. I had one time the sensor was seized to the valve stem by galvanic corrosion, such that the only way to remove the sensor was to destroy it in the process of removing it. You can prevent this from happening by applying a coating of anti-corrosion spray on the valve thread before installing the sensor. In general, those cheap (~$30) units are not built to last IMHO.

    The display unit will keep working even with one sensor dead. You just get only three displayed, and the unit will constantly warn you that one sensor is not functioning. I have not had any display unit quit working on me, but as I said, when you have one dead sensor, then you have to change the entire kit. There are some TPMS that can be programmed with a replacement sensor, but most cheap ones I have seen do not let you replace just one sensor.
     
    #16 Salamander_King, Feb 2, 2022
    Last edited: Feb 2, 2022
  17. PriusCamper

    PriusCamper Senior Member

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    I don't see anyone yet mentioning the fact that the decision you make is primarily a decision about your tires and when to replace them... It's not worth the cost to have all your tires unmounted and remounted unless you're changing them out. If you lived in a colder climate you'd have this option when you switch to snow tires every year, but you don't.

    So if I were you, I'd start dreaming up new wheels and tire plans and when to best do that and in the meantime put some tape over your TPMS light and be obsessed with checking tires before each drive and pulling over right away if there's any sense you might have a flat.
     
  18. PriusII&C

    PriusII&C Active Member

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    Yeah, I agree with you that it is not worth to pay a tire shop specifically to change TPMS sensors. Since we are on this topic, I wonder how hard/easy it is to do this DIY. Like @Salamander_King, I also watched a few Youtube videos in which the DIYers break the tire bead with a scissor jack and replace the TPMS sensor. I just have never done this myself, and don't know how likely things will be messed up.
     
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  19. Salamander_King

    Salamander_King Senior Member

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    Changing the internal TPMS sensors DIY is one thing I have not done. Yeah, on the video, it looked easy enough, and I was thinking of doing it on my winter rims and tires which did not have TPMS sensors. I was using the external TPMS on those tires, but after three external TPMS kits, I wanted to switch back to internal sensors.

    In the end, I did not DIY it, because the winter tires and rims had regular rubber valves, but the TPMS sensors I bought were aftermarket programmable metal valve Autel MX sensors. The weight difference was large enough that I would need to rebalance the tires which I could not do DIY. So, at that point, I just took the winter tires on the rim to a shop to install the sensors (and valves) and had them rebalanced. I wanted to wait for the next set of tire purchases, but I am not driving much nowadays, my winter tires are going to last many years before requiring replacement.

    One thing you have to keep in your mind is that even if you can DIY replace the internal TPMS sensors, for option 1, you will need to re-program the new sensors to the ECU. That is going to cost you if you have a shop to do it. In my case, I purchased the Autel TS508 TPMS tool and programmable TPMS sensors. The new sensors I had the shop install on the winter wheels had IDs cloned from the summer wheels using the TPMS tool. I can use the tool to re-learn the ID each time I swap the tires, twice a year, but now I have two sets of tires with identical TPMS IDs, so that I can swap and go without ever re-learn the sensor IDs on ECU.

    upload_2022-2-2_16-12-19.png
     
  20. PriusII&C

    PriusII&C Active Member

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    You are right. If I choose option A, I will need a Toyota dealer to do it (OEM), or a tire shop to do it. Based on people's posts on internet, it seems that it is not unusual for a tire shop to have difficulty in reprograming the new sensors. My local Toyota dealer, on the other hand, charges $800 - $1000 for this job. Either way, option A looks like the last option for me.

    If I decide to install internal sensors, I probably will go to option D. The potential issue is the display will lose track of the sensor locations after tire rotation. Like @PriusCamper suggested, I probably will wait until new tire installation. Meanwhile I will probably relay on option C while waiting.
     
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