General Tyre pressure warning light

[Derbyfella]

Just had this come on in the wifes 16 plate pop. None of the tyres look soft _ and yes i will check, but all i've got currently is a pump with a gauge...

My question is, how likely is this to be an issue with the sensor?

 

[John202020]

The actual tyre pressure is not monitored, unlike the first generation systems, the monitoring is "assessed " by using the abs sensors the theory being a low pressure condition would give a different rolling radius hence it suggest a possibility of low pressure then indicating you need to check?
However a badly worn tyre say and 3 new can also trip the system up, as can a failing abs sensor so check all tyres for pressure condition type etc?
Also two new tyres at the rear and two old at the front could confuse things

 

[Derbyfella]

The actual tyre pressure is not monitored, unlike the first generation systems, the monitoring is "assessed " by using the abs sensors the theory being a low pressure condition would give a different rolling radius hence it suggest a possibility of low pressure then indicating you need to check?
However a badly worn tyre say and 3 new can also trip the system up, as can a failing abs sensor so check all tyres for pressure condition type etc?
Also two new tyres at the rear and two old at the front could confuse things

surely then changing wheel size would also do this?

 

[John202020]

surely then changing wheel size would also do this?

As long as they're all the same then no
It's the constant different rolling rate with respect to the other 3 fully inflated ones that it looks for

 

[lindyhart]

Just had this come on in the wifes 16 plate pop. None of the tyres look soft _ and yes i will check, but all i've got currently is a pump with a gauge...

My question is, how likely is this to be an issue with the sensor?

I have a 2012 Fiat 500 Lounge. Same problem started about five years ago. I had the sensor replaced for $114. It did not solve the problem. I have had new tires put on and it was better, but still shows up for my left front tire. I check the pressure always and I'm OK. I don't worry about it anymore, just a fluke. (a friend who owns a Caddy, said she had the same problem) Guess it happens as the vehicle gets older!