Had the car about a month and got front right tyre pressure warning so checked and it was 40psi+ all round which surprised me as pillar label suggests 34. Reset them all to 34 and now get tyre warning for all 4. The warning clears then comes back. Tried increasing all to 38 but persists Any ideas ? 

If you only got the car a month ago, I would be straight back to the dealer with the problem. If it was a private sale, its probably worth asking if the problem is legacy and also looking the the actual sensors. very odd for all 4 to go though. Do you have a code reader?

Took it to a local Jag specialist and they kindly had a look. They are confident its the TPMS sensor. Apparantly the have a limited shelf life (internal battery?) . I'll live with it till the MOT as I suspect its a faliure.. 

The tyre pressure label should give you the recommended pressures for 'standard' or 'fully laden', the standard tyre pressure is significantly lower than the one for a fully loaded car.

Due to these two options, I think you can set the TPMS sensor warning for 'standard' or 'fully loaded'  in the cars menu system ?

Ie. If set to 'normal' load, it is looking for pressure readings dropping below (for example) 34 PSI before triggering the warning.

If set to the the 'fully loaded' option, it is looking for pressures dropping below (for example) 40 PSI.

This would be a possible explanation for the warning coming on for all four tyres once you dropped the pressure to 34 PSI all round ?

 

I could be barking up the wrong tree but might be worth checking the handbook ?

 

I can`t help....but I can sympathise. I have a similar problem with my XKR. The pressure warning light comes on at random, showing all 4 wheels in turn, then clears itself for a while. Actual pressures are fine. I`ll keep watch here for any advice!

Im glad im not alone....