Low tire pressure warning (pressures are not low)

Discussion in 'Clarity' started by ozy, Feb 11, 2019.

  1. ozy

    ozy Active Member

    Today I received a low tire pressure warning on my dashboard. What was unusual is that I recently let out air from my tires because the dealer had sold me the car with pressures of 50. After a month of driving around that way I realized the pressures were too high and released air to a pressure of 39 in each tire (about 5 days ago). I checked the pressures today with a professional longacre pressure gage and they are all identical (39). Anyone have any idea of why this warning message came through?
     
  2. Tahuna

    Tahuna Member

    Sounds to me like they're too high if anything. Check the door jamb, but I think they're supposed to be at 36. If they're all correct you can reset the warning through the settings menu.
     
  3. KentuckyKen

    KentuckyKen Well-Known Member

    The warning in the Clarity does not arise from low tire pressure, just from one or more tires at different pressures. It’s an indirect measurement made from comparing the rotational speed of each tire which is affected by the size (circumference being important in this case). Just about anytime you air up or down a tire, you need to recalibrate.
    The bad news is that it’s not very accurate and the good news is that there are no sensors in the tires to go bad or need battery replacement.
    I would not count on it to tell me when to check tire pressure if I wanted to get the maximum tread life possible. It is however good for warning you on a trip that you’ve got a tire going flat so you can keep those very expensive wheels off the pavement.
    Just adjust all 4 tires to 36 psi cold and then recalibrate.
     
    insightman likes this.
  4. 4sallypat

    4sallypat Active Member

    Recalibrate means to reset the TPMS sensors after adjusting pressures ?
     
  5. Mark W

    Mark W Active Member

    The problem here is that the Clarity requires you to go through a process using the LCD display menus to reset the warning. Sorry, I don't recall how to get to it, I'm sure someone will chime in with instructions. How is a driver expected to know this? Do other cars behave this way?
     
  6. KentuckyKen

    KentuckyKen Well-Known Member

    Here you are.
    From the manual p 425ff.

    Tire Pressure Monitoring System (TPMS)Instead of directly measuring the pressure in each tire, the TPMS on this vehicle monitors and compares the rolling radius and rotational characteristics of each wheel and tire while you are driving to determine if one or more tires are significantly under-inflated. This will cause the low tire pressure/TPMS indicator to come on and a message to appear on the driver information interface.

    You must start TPMS calibration every time you:
    •Adjust the pressure in one or more tires.
    •Rotate the tires.
    •Replace one or more tires.

    Before calibrating the TPMS:
    •Set the cold tire pressure in all four tires. Checking Tires P.499
    Make sure:
    •The vehicle is at a complete stop.
    •The gear position is in (P).
    •The power mode is in ON.

    ■TPMS Calibration
    Tire Pressure Monitoring System (TPMS)The system does not monitor the tires when driving at low speed. Conditions such as low ambient temperature and altitude change directly affect tire pressure and can trigger the low tire pressure/TPMS indicator to come on.

    Tire pressure checked and inflated in:
    •Warm weather can become under-inflated in colder weather.
    •Cold weather can become over-inflated in warmer weather.The low tire pressure/TPMS indicator will not come on as a result of over inflation.
    The TPMS may not function properly if tire type and size are mixed. Make sure to use the same size and type of tire.
    2Checking and Maintaining Tires P.499

    The low tire pressure/TPMS indicator may come on with a delay or may not come on at all when:
    •You rapidly accelerate, decelerate, or turn the steering wheel.
    •You drive on snowy or slippery roads.
    •Snow chains are used.The low tire pressure/TPMS indicator may come on under the following conditions:
    •There is a heavier and uneven load on the tires, such as when towing a trailer, than the condition at calibration.
    •Snow chains are used.

    You can calibrate the system from the customized feature on the audio/information screen.
    1.Set the power mode to ON.
    2.Select.
    3.Select Settings.
    4.Select Vehicle.
    5.Select TPMS Calibration.
    6.Select Cancel or Calibrate.
    When the calibration is complete, the display returns to the customization menu screen.
    •If the Calibration Failed To Start. message appears, repeat steps 4-6.
    •The calibration process finishes automatically.1TPMS Calibration
    •The calibration process requires approximately 30 minutes of cumulative driving at speeds between 30-65 mph (48-105 km/h).
    •During this period, if the power system is turned on and the vehicle is not moved within 45 seconds, you may notice the low tire pressure/TPMS indicator comes on briefly. This is normal and indicates that the calibration process is not yet complete.

    If snow chains are installed, remove them before calibrating the TPMS.If the low tire pressure/TPMS indicator comes on even when the properly inflated specified regular tires are installed, have your vehicle checked by an authorized Honda Clarity Plug-In Hybrid dealer.
    We recommend that the tires be replaced with the same brand, model, and size as the originals. Ask an authorized Honda Clarity Plug-In Hybrid dealer for details.

    The indicators for the Vehicle Stability Assist (VSA®) System, Vehicle Stability Assist (VSA®) OFF, low tire Pressure/TPMS and Collision Mitigation Braking SystemTM (CMBSTM) may come on along with a message in the driver information interface after reconnecting the 12-volt battery. Drive a short distance at more than 12 mph (20 km/h). The indicator should go off. If it does not, have your vehicle checked by an authorized Honda Clarity Plug-In Hybrid dealer.
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    Last edited: Feb 12, 2019
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  7. leehinde

    leehinde Active Member Subscriber

    KentuckyKen is full-service.
     
    MrFixit, insightman, MPower and 2 others like this.
  8. Fast Eddie B

    Fast Eddie B Well-Known Member

    To be clear, there are no TPMS “sensors””, per sé.

    The only sensors are those that measure the rotational speed of each wheel and the system alerts if they get sufficiently out of synch.
     

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