TPMS Light?

[Sal-XK]

Well the max rated pressure on tires is for max load the max setting are usually more in the 60 to 80 PSI range Matt can speak more to that issue. I don't think the TPMS detects differences in pressure from tire to tire to cause it to go off I believe it has a max and min settings for each tire I just don't remember what the setting are.

[Matt]

The max on your sidewall does not denote what the tires should be run at. Especially if they're stock, look at what the door placard says. Those pressures were calculated for your vehicle running the stock tires.

Granted if you want to run higher, that's your choice. But its really not needed especially if you're not running around fully loaded.

I'm not sure what the upper limit for the TPMS is on these vehicles, but its also possible your light is going off for an "over inflation" condition.

[Sal-XK]

Ya I'm pretty sure there is a MAX PSI number that will trip the sensor. I just can't remember what is. I think someone needs to bust out there new books and take a look

[Matt]

Stock tires a P-rated which usually have a max inflation pressure of 44psi. The LT rated tires have max pressures of 60 and 80 for D and E load ranges respectively. Regardless of which tire we're running, you shouldn't ever have a D or E load range tire run at max pressure on these vehicles.

I put a write up in the How To section to help people determine pressures for non-stock tires. Its actually dangerous to run over inflated tires..... its not just a harsher ride.

[Matt]

Ya I'm pretty sure there is a MAX PSI number that will trip the sensor. I just can't remember what is. I think someone needs to bust out there new books and take a look

Lol maybe I will when I get home. For my GMC the over inflation trigger was around 47 psi. But that was a full-size pickup that had a considerably higher GVWR than our XKs.

[sean112280]

Whats a good pressure to have then?

[Sal-XK]

I would go by whats on the sticker inside the door if you're running stock tires. Over and under inflation will cause uneven wear and crappy MPG.

[Matt]

Yeah, for stock tires run the pressure stated on the door placard (I believe its 35).

If you're towing or fully loaded then bump up the pressure for some sway control. (Not necessary, but not a bad idea either)

[sean112280]

Thanks guys! Ill fix that then

[LWM]

The tires are stock with a max of 44 psi.35 psi is to low for me. Sal the spare is off right now due to me finding it to be flat and it needing to be plugged. I dont know if that will have anything to do with it.

On the limited, the spare is monitored by the system. My spare is not there and my light is constantly on. You might want to get your spare back in there and see if the light goes off.