Tyre pressure monitor

[cmc]

After a couple of months of driving and being generally lazy I decided to check my tyre pressure and noticed my tyres were down at about 29 psi which is a reasonable amount down on the recommended pressure.

Now I would have thought the tyre pressure monitor feature would have picked this up but it didn't. Does anyone know why or how this works in practice (i.e. is it only on a severe deflation like a blow out - in which case I think you would be acutely aware anyway ).

Cheers

cmc

 

[P0LKR]

i too was a bit confused about this....im told by the dealer that the pressure must be significantly changed ie 15psi over a short space of time

 

[DanGB]

As far as im aware it measures the rolling differences through the ABS sensors between each wheel, so will only pick up a difference if the tyres are different pressures. ie; havent all deflated gradulaly.

 

[dchbrown]

from what i know it does work on the ABS sensors but i can say that it works when you do actually have something wrong!!

it went off the other night for me and id lost about 5psi in one tyre. when it was light i couldnt see anything wrong with the tyre so just thought nothing was wrong. about 4-5 days later it went off again - turned out i had a slow puncture from a tack in the tyre.

i can vouch for the fact that it does actually work when you need it but not as a replacement for checking the pressures every week/month etc.

 

[johnfbr]

Nice feature

I can also vouch for this. Lost 4/5 psi in rear offside tyre and warning light came on. On inspection, nail in centre of tyre. Down to kwikfit, £10 repair luckily.

 

[Cupra R]

As far as im aware it measures the rolling differences through the ABS sensors between each wheel, so will only pick up a difference if the tyres are different pressures. ie; havent all deflated gradulaly.

This is how I was told it worked too. Via the rolling radius.

 

[Carnivor]

yes its the circular movement that is timed, when a tyre deflates the timespan will change and the alarm sound, so gradulal degredation of air pressure over months is well out of its scope, but if the same happened in say 100 revolutions of the wheels off goes the alarm.