I know there are other threads on this subject, and I did go thru several. Here's what I'm wondering about, car is a 2007 XK: When I start the car, I get the single TPMS yellow light, goes out immediately. I have another set of wheels/tires that I'm going to put on the car, wheels are from an XJ, probably 2007-2011. I mounted one to see if the sensor would be recognized. Started the car, display was normal. Took a short drive, maybe 1/4 of a mile, all seems normal. I dropped the pressure down to about 20PSI, and no TPMS warning light. So, if the batteries are shot, would I still get a steady light or no light at startup? Since the TPMS light comes on at startup, does that indicate the batteries are good? TIA

 

The different in-wheel sensors take "under" 20 miles to reset, so if you didn't go far enough nothing registered yet. The system only works while the wheels rotate, so nothing would register while still.
Go take a bit of a ride and report back.

 

Thanks, I'll check this out. On a related topic, what is the behavior of the dash icon if the sensor batteries are bad?

 

I can't remember the exact terms right off hand, but something like No Signal or Fault on any bad locations. It'll tell you where the problem is if it is ONLY bad batteries. Or low pressure.
A TPMS SYSTEM FAULT displayed means that something else is wrong.

 

Joe,

You're in Philadelphia. Take your XK to any national chain tire retailer and ask them to scan all 4 of your tires for the remaining life of your TPMS batteries. Note the MaxiTPMS battery testing tool used by the technician at 1:51 of this YouTube video.


If any TPMS sensor has a low battery, you should replace all 4. Use only the OEM VDO/Continental 315 Mhz sensor, which needs no programming. Check prices on Rock Auto and your local auto parts stores.

Stuart