2012 xjl. The system doesn't show the tire pressure for each tire. My question is that I've read about all the problems with TPMS on the xf and xk . I think my tires are just a few psi low and need to inflate them back to 34-35. Do I need to inflate while the car is running? Or with the car off? I've seen a lot of posts about having to deflate tires all the way down to about 16 psi and then inflate. I just want to add a few psi but I don't want to incur all the problems with the system rolling and scrolling and not working properly. Any suggestions?

 

Hey mate, I have 2011 XJL and haven't had any issues with the TPMS system...it warns me correctly when the tire pressure gets low. As for inflating them back to the recommended pressure, I haven't had to do anything of the sort mentioned in your post except to just fill up the air to the pressure which I want. I do usually fill up the air when the car is running since I use a kit which is attached to the cigarette lighter socket, so maybe that is the safer thing to do...keep the engine running when you fill it up.