Tyre pressure monitoring system

[Daz68]

Hi All,

Had my Cupra for 3 months. It came with P-Zero's. A week and a half ago one them (rear right) was punctured with a 2" screw and had to be replaced, so you can imagine I wasn't too pleased when my TPMS light came on today for the other rear.

I stopped and had a look at the tyre (rear left). It didn't look flat and I couldn't see anything sticking in the tyre, although it was dark by this time. Took it to the local petrol station. My back pressures are supposed to be 35psi. The machine said 33 so I topped it up to 35. Checked the other side, it was 33 as well. So even taking into account that the pump meter wouldn't be 100% accurate I didn't think that difference was too bad.

The only thing I did notice when I checked the tyres was they had a fine coating of chippings on them from the car park I use during the day. You can actually hear them falling off as you drive away.

So my questions are:

Is a few psi difference enough to trigger the warning?
Could the coating of chippings affect the calculations of the TPMS and fool it into thinking the diameter of the tyre had changed?
Or is there something else I should be worried about?

Sorry for the long post, but I would be interested in what everyone thinks?

Thanks.

 

[Dt-spd]

A few psi is enough I have found.
Dont think chippings from the car park would make any difference

After the puncture a week ago did you reset the TPMS system ?
Once you reset them to 35 today did you reset the TPMS system ?

 

[chrisRibiza]

My TPMS has only ever went off once, I went straight to a petrol station and couldn't find anything wrong with the tyres but just made sure that all of the air pressures were equal and then reset the system.

It has never went off since.

Not sure if something on the tyre would confuse it but i'd say just keep an eye on it over the next few days and if it goes off again then it may be a trip to the local tyre depot to get the tyre checked properly.

 

[CupraUK]

get them to check abs sensors if it keeps doing it, they control the tpms

 

[Redline]

How does the tyre pressure sensor work?

 

[Daz68]

A few psi is enough I have found.
Dont think chippings from the car park would make any difference

After the puncture a week ago did you reset the TPMS system ?
Once you reset them to 35 today did you reset the TPMS system ?

Thanks for the quick replies.

Yeah I reset after the puncture. I was running on the pram wheel for a couple of days so that was setting it off. Funnily enough the puncture didn't but I guess the screw was plugging the hole.

And yeah reset it again tonight.

I'll keep an eye on it as suggested. Hopefully it's just over sensitive.

 

[trebor]

How does the tyre pressure sensor work?

As I understand it on the Leon it is a passive system.
There are no pressure monitors like on an active system, instead the system monitors the difference in wheel rotation speeds across each axle via the abs sensors. Theory is if you get a flat the tyre deflates so it turns faster than the other and triggers the warning.

 

[Redline]

As I understand it on the Leon it is a passive system.
There are no pressure monitors like on an active system, instead the system monitors the difference in wheel rotation speeds across each axle via the abs sensors. Theory is if you get a flat the tyre deflates so it turns faster than the other and triggers the warning.

Thanks.

 

[matthab]

Had mine come on saying check tyre pressure but didnt mention a tyre. Checked the pressure with my gauge and all were fine. I put it down to the front tyres getting to the point where they need replacing in a couple of months.

 

[eoink]

I've had mine go off a few times when one side drives on water and not the other side.
I always do a reset when I get to stop and see if it goes off again.

If not, I'm happy that it was just that rotation speed difference.

If it does, I have always found some source of air leak (nails, screws, daggers).