tpms sensor reading low
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Joined: Apr 2012
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tpms sensor reading low
out of the blue my tire light came on for drivers front. system showed 30psi but my guage showed 40 psi. so i reset the system topped all the tires back off at 40psi, and it still reads low on that tire. the rest are within 1psi of my guage.. bad sensor?
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Joined: Mar 2021
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Tpm variance over time and temperature is very interesting in that there is no real base line pressure to be sure of.
Only time a near standard pressure base is at night after the truck has set and all is cooled down.
On my 18, the TPM system is 1 psi in resolution.
One out of the 4 is one psi different.
Using a digital gauge that reads to 1/2 psi, set all wheels to the same pressure no matter the actual accuracy of the gauge, all are the same base pressure at that time and the TPM dash 35 setting except the one tire now known to be inaccurate..
The wheel that was off by 1 psi is still off by the same amount on the dash readout. No problem as long as we know the Monitor is off.
By rotating the wheels every 5k miles the same wheel was off by the same amount in any other position.
While driving, the pressures are all over the place so driving is not the time to try having tires at all the same pressure.
Only time that might happen is a on a long straight run at night when the tires should have the least variances at near constant speeds.
Also a low tire will heat >faster< than a higher pressure tire and fool you in the monitor as well as a faulty tire can do the same.
A lot of dynamics in play we could never see until TPM came along if one takes the effort to track it over time.
What with electric assist power steering now, tire pressure changes in the front can add to a different feeling at times, in the steering.
I had a bit more caster set in my truck to make the steering more stable and run the tire pressure at 35 cold to make ma happy due to the firm riding suspension. The pressures rise to about 38 at the most during hot weather and the tires have 45k miles and still not ready the be replaced.
Only time a near standard pressure base is at night after the truck has set and all is cooled down.
On my 18, the TPM system is 1 psi in resolution.
One out of the 4 is one psi different.
Using a digital gauge that reads to 1/2 psi, set all wheels to the same pressure no matter the actual accuracy of the gauge, all are the same base pressure at that time and the TPM dash 35 setting except the one tire now known to be inaccurate..
The wheel that was off by 1 psi is still off by the same amount on the dash readout. No problem as long as we know the Monitor is off.
By rotating the wheels every 5k miles the same wheel was off by the same amount in any other position.
While driving, the pressures are all over the place so driving is not the time to try having tires at all the same pressure.
Only time that might happen is a on a long straight run at night when the tires should have the least variances at near constant speeds.
Also a low tire will heat >faster< than a higher pressure tire and fool you in the monitor as well as a faulty tire can do the same.
A lot of dynamics in play we could never see until TPM came along if one takes the effort to track it over time.
What with electric assist power steering now, tire pressure changes in the front can add to a different feeling at times, in the steering.
I had a bit more caster set in my truck to make the steering more stable and run the tire pressure at 35 cold to make ma happy due to the firm riding suspension. The pressures rise to about 38 at the most during hot weather and the tires have 45k miles and still not ready the be replaced.