Driving home on a hot - for Western Canada - 90F day, and the TPMS light came on. Drove 20 miles home, put vehicle in garage overnight. Check tire pressures in morning, three are 34psi, one is 32 psi. Let the tires down a bit and then aired them up to 34 psi. Checked twice. All 34. Pressed the "TPMS reset" switch for 3 seconds, TPMS light went out then went for a ten-mile drive. TPMS light has stayed off for about 25 miles now.
This is the TPMS system that uses the ABS/Traction control wheel speed sensors to detect the "differential" between wheel speeds. When you press the "TPMS Reset" button, the TPMS computer presumes you have correctly adjusted tire pressures, and the system spends the next several miles "learning" the difference - if any - between the four wheels. Difference would exist if the tires are not perfectly evenly worn; the tiny difference in rolling circumference is compensated for by the TPMS computer during the Reset / initialize process.
Question to the rest of the forum... has anyone else noticed over-sensitivity of the TPMS system on hot days? Any other conditions where TPMS light comes on, and tire pressure found to be normal?
The whole "TPMS" discussion about the lack of usefulness of a system that only reports an "abnormality". Ideally, when I'm driving at 70mph on the highway, and something goes "wrong" with the car, I want/need to know "how wrong is it?" In the case of tire pressure, that means what was the pressure a minute ago, what is it now, and what is it in another few seconds. If its dropping fast, that means get off the freeway NOW. If its dropped 1 psi in the last week, and drops no more psi's in the next hour, that means I can easily make it to the next town or even the next province. Yes, TPMS of this flavour is as close to useless as useless can get.
Thankfully subsequent TPMS systems are more "useful" in that they report actual pressure - albeit 15 seconds ~ a minute or two delayed. More useful than an idiot light, but still not "real-time".
Anyways enough ranting.... I'd be interested to hear of others' experience with over-sensitivity of the differential wheel speed type TPMS.
Thanks.
This is the TPMS system that uses the ABS/Traction control wheel speed sensors to detect the "differential" between wheel speeds. When you press the "TPMS Reset" button, the TPMS computer presumes you have correctly adjusted tire pressures, and the system spends the next several miles "learning" the difference - if any - between the four wheels. Difference would exist if the tires are not perfectly evenly worn; the tiny difference in rolling circumference is compensated for by the TPMS computer during the Reset / initialize process.
Question to the rest of the forum... has anyone else noticed over-sensitivity of the TPMS system on hot days? Any other conditions where TPMS light comes on, and tire pressure found to be normal?
The whole "TPMS" discussion about the lack of usefulness of a system that only reports an "abnormality". Ideally, when I'm driving at 70mph on the highway, and something goes "wrong" with the car, I want/need to know "how wrong is it?" In the case of tire pressure, that means what was the pressure a minute ago, what is it now, and what is it in another few seconds. If its dropping fast, that means get off the freeway NOW. If its dropped 1 psi in the last week, and drops no more psi's in the next hour, that means I can easily make it to the next town or even the next province. Yes, TPMS of this flavour is as close to useless as useless can get.
Thankfully subsequent TPMS systems are more "useful" in that they report actual pressure - albeit 15 seconds ~ a minute or two delayed. More useful than an idiot light, but still not "real-time".
Anyways enough ranting.... I'd be interested to hear of others' experience with over-sensitivity of the differential wheel speed type TPMS.
Thanks.