Just a warning to all of you that checked or adjusted your pressures the other week when it was really cold to re check them again, I did mine and set them to 2.35 bars all the way round and found today that my pressure in every tyre had actually gone up to 2.46:eek:

I always check mine hot, and add 3psi to compensate.

Stupid question but does anyone know what pressing the button actually does?

I would assume that it tells the system to check whatever value it uses and monitors for a reduction. BUT more often than not I press this while the car is Parked and don't use for a few hours.....so how does it get its "Value". Does it wait until next time the car is driven?

A lot of people have mentioned that it hasn't gone off, so what about for example inflating tyres to 35psi, press TPM, then let 2-3psi out and DON'T press monitor, will that mean it will go alarm earlier if you do loose pressure seeing as technically it's already lost 2psi.

Also one other thing would it make a difference to the Value taken when Tyres are Hot/Cold, I'd normally check mine when Cold, and set TPM then, but if you did the same when tyres warm, hit TPM, leave car for a while then if "Valve" is calculated during that journey then the tyres will be Colder so less pressure (kinda same as above).

Sorry for probably confusing the hell out of you, but everytime I see it mentioned the above thoughts keep coming back, so hence the stupid unasked question

ive had mine go off but the tyre had lost 6 psi. it did it a few times as i had a faulty valve and had a slow puncture in effect. Everytime i reinflated to 34psi the TPM alarmed at 28psi.

Pressing and holding the TPM button resets the value from which the TPM monitors. i.e in my case 34 psi

HTH

Carl:thumbup:

The button resets the stored value.

Thinking about a blow out, I assume the system sees the sudden dramtic loss as a possible error hence no warning. Where as a punture would be gradual loss.

As said, it's for the latter not the former

The button resets the stored value.

But what Valuve is that? It can't be an actual pressure reading as it has no direct way of measuring. IIRC its done by wheel rotation, but surely it can't calculate that value until the car moves. So hence the questions above.

Btw I'm not doubting anyones comments....just thinking out load