2006 dts performance tire monitor sys.

If you've never replaced the tire sensors and had the car since new then they are long overdue and I'm surprised they have lasted this long. If you weren't the original owner then perhaps over time prior owners have replaced them as they went dead. They are little sealed radio transmitter units mounted inside and are part of the valve stem. They have internal batteries that simply go dead over time and the batteries aren't replaceable as the units are totally sealed. Any good tire shop can replace them for you at about $70-$100 each including the labor - maybe cheaper if you shop around but they have to take each tire off the car and unmount it from the rim to replace each sensor. If the others are still good then just get them to replace the one that is dying. You can actually buy them on eBay and then have a shop replace them. The lowering and then increasing tire pressure while the car's display is in "Relearn Tire Sensor" mode - accessed through the dash buttons - is how you get the system to recognize the sensors. Most tire shops also have a tool they can use to bypass the air pressure changing procedure when they replace them.