This is getting extremely annoying now. The TPMS system just got its firmware updated at dealership and now 2 days later i get a tire pressure low warning. I am getting fed up with this but my tires were just inflated last week.
Is this because my wheels are 22" and the car cant tell if its right ?
Pic of car below

 

No, in that case it'd say "TPMS Fault" or something to that effect.

If it says your tire pressure is low, it's detecting that one (or more) of your tires is over or under inflated relative to the other tires on the car.

Just because they were recently inflated, doesn't mean that the person doing it bothered to accurately sync the tire pressures and also doesn't mean that you don't have a slow leak. If they had to remove the TPMS to update the firmware, my guess is you have a bead leak from when they re-mounted your tires.

Solution: Buy yourself a decent tire gauge (not the cheap pencil type). Everyone should check their tire pressures weekly - it's the most important part of your car.

 

How is tire pressure synced?

 

By inflating each to the same PSI, as measured by an accurate gauge.

 

Might be the thin tires are not able to absorb the impacts of the road & the sensors are being damaged? I like the looks of the rims, but I would imagine the ride would be rough. I have 19" rims and I don't care for the ride. I think the XJs aluminum body is designed VERY stiff.