Does the Tyre pressure Monitor actually work ?

[jk88]

Had the misfortune to pick up a rather large screw in one of the front tyres the other day, resulting in a puncture. As the screw was firmly embedded, there was no sudden deflation and I expect it might even have taken a couple of days to deflate to the point where it was visibly obvious. My wife mainly drives the car and she hadn't noticed anything wrong, but more concerning was the absence of any complaint from the TPM. I had recently adjusted the tyre pressures over Xmas and reset the TPM so it should have worked or am I missing something?

[Avidfanofstuff]

Possible that It wasnt letting any air out at all...

mine works perfectly (on audi) and is quite sensitive. Easy way to check is let some air out when your next at the petrol station and see if it triggers?

[jk88]

It let all the air out allright, albeit over a couple of days. The one on my Audi also works fine, just seems the one on our Golf doesn't.

[mattlittle]

Possible that It wasnt letting any air out at all...

mine works perfectly (on audi) and is quite sensitive. Easy way to check is let some air out when your next at the petrol station and see if it triggers?

The tyre pressure monitor works on the ABS sensor picking up changes to the momentum of the wheel rotating caused by deflation of the tyre. If you let air out of the tyre when the car is static, the TPM will definitely not trigger a warning.

[Avidfanofstuff]

The tyre pressure monitor works on the ABS sensor picking up changes to the momentum of the wheel rotating caused by deflation of the tyre. If you let air out of the tyre when the car is static, the TPM will definitely not trigger a warning.

Cheers for that. Nothing is simple these days is it!

[ziggycol]

It won't trigger while stationary but should when you start moving. As I understand it the TPM uses the ABS sensors to compare relative rotation of the different wheels. A wheel/tyre with lower pressure will have a smaller rotating circumference and hence greater rotation for a given speed than the other wheels. This is what the TPM detects.

[mattlittle]

It won't trigger while stationary but should when you start moving. As I understand it the TPM uses the ABS sensors to compare relative rotation of the different wheels. A wheel/tyre with lower pressure will have a smaller rotating circumference and hence greater rotation for a given speed than the other wheels. This is what the TPM detects.

Good point - I mentioned it as I assume that the suggestion of letting air out at a garage was that it was easy to refill from a garage's air supply before going back on the road.

[dickt]

Mine has worked twice. Early on in the car's life the tyres were massively over inflated by the garage. One tyre lost some of that, and the pressure warning came on. I reset it and changed the pressures on all four. It came on some months later as one had lost a smallish amount. Pumped up and re-set.

[aldfort]

Given how the ABS sensors work then the TPM is never going to be fool proof. It's a guide and may help you if you get a puncture at high speed but it's no substitute for regular checks IMHO.

[cdgthreesalmons]

Mine certainly worked.

Tyre Pressure monitoring is something I have never had on a car before – but wow was it useful the other day. Backing out of the garage the TPMS light/warning came on. A screw had punctured the tyre tread leading to a gradual (not complete) loss of pressure. I was able to put the car back into the garage, take the wheel to my local tyre dealer for a fix.

Without TPMS I would have set off on my long journey on a wet, manky day and would have ended up being stranded on the roadside changing a wheel.