Driving around Northumberland on Friday and the Tyre Pressure warning flashed up on my Fabia SE L. Everything felt/sounded normal so carried on until I found a reasonable place to pull off and had a look all 'round. Couldn't spot any obvious deflation in any of the tyres. Then found a little local garage and the owner very kindly checked all pressures. O/S/F tyre was showing "about 1.5 psi down vs the others". Nice man added a squirt of air, declined any payment and, after ressetting the TPMS system, off we went. Drove home some 200 miles to-day without any signs of a repeat warning...hopefully this is not tempting providence...and no deflation that I can tell.

Is the TPMS prone to these little glitches and what pressure differential normally triggers a warning?

Edited 17 April, 201610 yr by alltorque

Its not a glitch, it was doing it's job.

Maybe you have a slow puncture in that tyre?

Its not a glitch, it was doing it's job.

Maybe you have a slow puncture in that tyre?

You could be right and I will be keeping an eye on it. If it goes off again I'll get it into to my local tyre place.

Must trawl the handbook and see if it mentions what loss parameters it works to. 1.5psi seems pretty tight.

Get a pressure gauge - and use it?

Could also be a leaking valve.

My Fab has one tire very slowly leaking, and I have to check it once in a while - not often, mayby every 6th week or so - and Im thankful for the warning.

Know I should do something to that leak, but being a bit lazy, well you know... At least Im convinced that the ABS is working properly.

Get a pressure gauge - and use it?

Ah, that will be the one that normally sits alongside the little electric tyre compressor in the boot...but had been unloaded at the holiday cottage by mistake. It was the subject of some discussion between SWMBO and myself.

alltorque,

you never mentioned when you had last set your tyre pressures yourself and reset the TPMS before having got an alert and needing to check them.

alltorque,

you never mentioned when you had last set your tyre pressures yourself and reset the TPMS before having got an alert and needing to check them.

They were last checked last week of February folowing N/S/F tyre being replaced after sidewall was damaged by driving over a water-filled pothole.

I think I know where you're going with this.

I was asking if you had checked all 4 pressures and set them and then reset the TPMS, 

as many do not do it their self, or know about the Ambient Temps when checking say in a building and outside, 

and then might set fronts and rears to different pressures for loads carried and not reset the TPMS.

 

What pressure were you running on the one that then showed i little drop.

Sometimes a single PSI difference can be enough for the System (ABS) to pick up on the change of tyre circumference.

I was asking if you had checked all 4 pressures and set them and then reset the TPMS, 

as many do not do it their self, or know about the Ambient Temps when checking say in a building and outside, 

and then might set fronts and rears to different pressures for loads carried and not reset the TPMS.

 

What pressure were you running on the one that then showed i little drop.

Sometimes a single PSI difference can be enough for the System (ABS) to pick up on the change of tyre circumference.

Interesting comment re the 1psi. If the car were stood with, say, offside tyres in direct hot sunlight for some time, and nearside in shadow, would that not raise pressures in the offside tyres by more than 1psi? This obviously was not the case in a wet Northumberland, of course.

Hypothetically....

On a very wet road, dual carriageway for example, with patches of standing water and cruising at NSL on a trailing/light throttle...what if one driven wheel momentarily lost traction...would that trigger an ABS "event" to affect TPMS monitoring? What if same conditions but on a "positive" throttle? Just trying to understand likely effect of one system monitoring another system on which to base it's alarm parameters.

People get false alerts, you got an actual.   It is good, because it had you checking and the weather might have changed, 

altitude.  Barometric Pressure etc.

(But then it was the North of England and not the Alps.)

 

The system can not even alert sometimes when tyres have lost an even amount all round.

People might fit the spare wheel temporarily and no alert as they cover a short distance even though the tyre is a different size slightly.

 

Mine warns within a few hundred yards.

The System is designed to be Checked if operating as well as for Resetting, all covered in the Owners Manual.

People get false alerts, you got an actual.   It is good, because it had you checking and the weather might have changed, 

altitude.  Barometric Pressure etc.

(But then it was the North of England and not the Alps.)

 

The system can not even alert sometimes when tyres have lost an even amount all round.

People might fit the spare wheel temporarily and no alert as they cover a short distance even though the tyre is a different size slightly.

 

Mine warns within a few hundred yards.

The System is designed to be Checked if operating as well as for Resetting, all covered in the Owners Manual.

More to this than, at first, meets the eye. In the morning, whilst still "cold" I will reset all four tyre pressures to 2.3Bar with the mini compressor, check to see what my gauge reads and then monitor on a 48hr basis for a week or so. Thanks for the discussion.

With what purpose in mind, you have not had a warning since the last have you?

 

Maybe check your pressures when cold and then after a run up a motorway or the likes,

you might get a surprise how 1 tyres pressure car vary if the car is loaded a bit, or just the difference between the Driver side and passenger side if no passenger carried.

Get a pressure gauge - and use it?

How reliable are tyre pressure gauges?

I would like to get a new one to replace an ancient one I use but wonder whether any of them are actually any good.

How reliable are tyre pressure gauges?

I would like to get a new one to replace an ancient one I use but wonder whether any of them are actually any good.

More than being 100% precise it will help you having an even tire pressure which is most important for driving characteristics and safety.

Edited 28 April, 201610 yr by pfaff