TPMS

[Ironinventor]

So I have a 2022 vw polo life and seem to have a recurrent issue with the TPMS. I have had the light come on twice. Both times when checking the tyre pressure the rear left tyre seems to have a lower pressure by about 2 psi compared to the rest. Initially i thought it might be a slow puncture but i didnt appear to be losing any pressure in the tyres even after some 400-500 odd miles of driving at various speeds. Recently (yesterday) have had all the tyres changed including that one and the sensor lit up again today. Sure enough that tyre was about 2psi below what it should have been (granted I forgot to do my due diligence checking the pressures after i collected my car) - discovered the garage had under inflated all the tyres so it might have been in a fluke except that rear left tyre was about 2psi below the other 3 when i pulled into a car park to check and add pressure to the tyres. I reset the TPMS once setting the correct pressures in all the tyres and have been on my way now home after a 160 mile round trip the systems not activated itself again but I am a bit new to all of this car diagnostic stuff so was wondering if anyone could give me any pointers as to what i might be expecting. Planning on taking the car in to a reputable local garage to check it out in a couple weeks - just going to have to use my partners car for a bit. Should I contact the main dealer as well - in a way want to avoid them given how useless they seem to be at responding to simple enquiries even hanging up on me mid call.

[lancslad1985]

Just be aware temperature changes can have an impact on tpms. Every year when we get to autumn and suddenly have a cold night, my tpms will go off saying the pressure is low and it’ll be barely noticeable. Had this happen on every car I’ve had with Tpms.

As a result with this car I check the pressures every 2-3 weeks and adjust as necessary. Touchwood it hasn’t gone off yet.

[SRGTD]

As @lancslad1985 has said, temperature changes can trigger a warning; I had this happen in my previous car when there was a sudden drop in the overnight temperature one winter.

Have you or anyone else who may have driven your car had the misfortune of hitting a pothole or raised drain cover or clipped a kerb while driving at any point in the past? (with the general poor state of the roads, it can happen). If the wheel or tyre on the rear left of your car has suffered damage, it could be that it’s not possible to create an effective seal between the tyre and the wheel, allowing air to slowly escape. If so, and if any damage is on the inside of the wheel/tyre then it won’t be visible unless the steel is removed from the car. Also worth checking first that the tyre valve isn’t leaking as it’s easier to do than getting the wheel removed; remove the valve cap and smear or spray a mixture of water and soap solution (washing up liquid) over the end of the valve; if bubbles appear, then the valve is leaking.