First, it's TPMS sensor. The TPMS control unit, which is built into the BCM, recognizes the sensor by where it was registered. Meaning, if you registered you sensors, which go in the order of left front, right front, right rear and left rear, that is where the TPMS controller assumes is the position of the sensor. If you were to have a slow leak at the left front tire that caused the TPMS warning light to go on, it would, at that point, trigger the code for the left front tire. However, let's say you rotated the tires front to rear and did not re-register the TPMS sensors. That same tire still has a slow leak and still triggers the code for the left front wheel, even though the actual position of that wheel is now in the left rear position. The same would be if you rotated that tire to the right rear position; if it were to go low, it still would trigger the left front position because that's where the tire was originally when it was last registered. So, the bottom line, if you want the TPMS controller to be accurate when it triggers a code, you need to re-register the TPMS sensors whenever you rotate the tires. Now, in order to find your problem sensor, you'll need to re-register the sensors and then erase the codes and see what code pops up. If a sensor doesn't register during the process, it's likely a dead sensor and needs to be replaced.