Tyre pressure warning lights up, tyres are fine

zee34

Hey all, 

I have a 23' Seat Ibiza FR with 9k miles on it.  The low tyre pressure warning for all 4 tyres started to light up every now and then. Mainly after I drive fast , 70-75mph for extended period of time. I check my tyres , they are all fine , I reset the warning on the screen and its fine for a while then after few days it might be back again. 
It is due for its first service so I will take it in but any Idea what could it be when the car is less than a year old still. Luckily the warranty should cover it but it is annoying having to pull over, check tyres and/or feeling anxious about my tyres while driving on motorway. 
Do the sensors overheat?? But all of them? Are they dirty maybe? I did drive in Wales on some dirty single track roads. Anyone who experienced this issue before? I cant find information about it online. 

badmemory

Mine regularly do this but you have to check them just in case, don't you.    Mine usually come on when the car has been sat in the garage & it is quite cold.  If I drive several miles to the motorway in one direction then no problem.  If I go the opposite way & the motorway is much closer & less congested so faster then tyre problem is more possible.  I've had this VW for 9 years now since new & the first time this happened I called the AA & they couldn't find a problem.  The interesting thing is that mine should if anything be recording too high rather than low pressure

Goudy

zee34 said:

Hey all, 

Do the sensors overheat??. 

No but the air in your tyres will heat up and expand when driven fast which effects the system it uses to detect the tyre's rotational speed.

I seem to think there are no pressure sensors within the tyres on these but it utilises the ABS sensors.
If a tyre is low it effects the rotational speed compared to all the others and the system detects it.

It's also prone to work the other way around, it can think three may be under rotating (so therefore under inflated) if one tyre is markedly over rotating because if it's over inflated (or heated up).

Some systems are overly sensitive (others not so) which mean you usually need to set all the pressures within a pretty narrow range to stop them setting the system off and it can take a bit of practice finding the sweet spot.

Also once adjusted the system usually needs telling, there should be a menu setting that lets you reset or reinitialise the system after you have adjusted the pressures.

It's also worth remembering, there'll be a few mill more worn off fronts than the rears on a FWD car after 9k.
This can also effect the rotational speed compared to the rears as the rears don't do much except keep it's !!!!!! off the ground.
The fronts will heat up at a faster rate as they suffer heat from the brakes soaking through, they are the driven wheels so under power and they have more weight on them.

Mr.Generous

Make sure you set them with an acurate pressure guage, not one attached to a pump - even at a garage, these are hopeless.

JosephK

Had similar on mine (Ford Fiesta) a couple of times near end of last year. It was during period of exceptionally wet weather and I'd had to drive through standing water a few times. Checked pressures and they were OK, warning lights went off later when, presumably, sensors had dried out properly.

Could it be a similar problem with yours?

zee34

JosephK said:

Had similar on mine (Ford Fiesta) a couple of times near end of last year. It was during period of exceptionally wet weather and I'd had to drive through standing water a few times. Checked pressures and they were OK, warning lights went off later when, presumably, sensors had dried out properly.

Could it be a similar problem with yours?

Maybe, i did drive through a flood as well in Wales...it was bit deep, half covered the wheels. Hasnt come on since saturday now. So maybe they were wet

zee34

Mr.Generous said:

Make sure you set them with an acurate pressure guage, not one attached to a pump - even at a garage, these are hopeless.

Its having its service on Friday i will get them to check. 

Goudy

zee34 said:

JosephK said:

Had similar on mine (Ford Fiesta) a couple of times near end of last year. It was during period of exceptionally wet weather and I'd had to drive through standing water a few times. Checked pressures and they were OK, warning lights went off later when, presumably, sensors had dried out properly.

Could it be a similar problem with yours?

Maybe, i did drive through a flood as well in Wales...it was bit deep, half covered the wheels. Hasnt come on since saturday now. So maybe they were wet

Maybe the drag of the standing water suddenly slowed the wheel rotation down so the system thought there was a problem with the pressures.