More tyre pressure monitor problems

[emagstar]

Back in 2020 I bought a 2018 polo and had all sorts of problems with the tyre pressure warning light coming on all the time despite all the pressure being fine.

I posted about it here: viewtopic.php?t=75252

I took it into VW several times and they blamed it on the difference in tread depth between the two front tires and swapped in the spare which had a similar tread depth to the other tyre. This also didn't seem to solve the problem. What did eventually solve the problem was reducing the two front tyre pressures to the "comfort" pressure of 32 psi rather than 36 psi. After I did this, the warning never happened again (over 2 years).

The other day one of my front tyres was worn enough that it needed replacing, so I got a new tyre. Ever since then the warning has been coming back everyday. Each time I check the pressures and they are fine and reset the TMPS. Today I have reduced the pressure to the "comfort" pressure of 32psi again and the warning has not happened today as it normally would.

Why on earth would having a lower pressure on the front two tyres cause the system to behave?

[iichel]

That's something I can only answer when VW shows me the algorithm that controls the system.
My guess is, with the higher pressure, the tolerances are more easy to exceed. Tread depth should not play a role since you can reset your TPMS system and it will adapt for small diferences.

Perhaps it could have to do with the hot weather we're having, that leads to higher temperatures and perhaps differences in temperature, and that together with a higher pressure is an easy trigger for the TPMS system.

[emagstar]

Yeah that was my guess too, that it might be a combination of difference in tread depth, high pressure and hot temperatures that is causing it. Still the system shouldn't be triggering if the tyres are at the correct pressure even if it is a bit hot.

Frustrating you can't adjust the sensitivity off the system, I am guessing VW wouldn't be able to adjust the sensitivity either?

[SRGTD]

I had one false TPMS warning with my previous generation 6c Polo GTI which I put down to the outside air temperature - in my case, it was a near-zero temperature during the winter months.

I checked the tyre pressures and they were all OK, reset the TPMS I never had any other false warnings during the ownership period of that car, and I’ve not had any in my current AW model Polo GTI+.

[emagstar]

Spoke too soon, it just triggered again.... going to try get it booked in tomorrow

[lancslad1985]

I’ve usually had tpms triggers when the weather has changed. So if I set the tyre pressure in warmer weather in late summer and then it’s gone cold for example. The tpms must think the tyre has not got up to expected pressure for the temperature and triggers. Every time I’ve got out to check, the tyre has been fine. Was the same on my Volvo as well as my VWs.