I recently put my summer tires on the car.  I started going through the relearn sensor process.  It picked up the first 3 sensors but it is not getting the information from the 4th sensor.   If I go to the sensor information option it picks up that it is an OE sensor. I bought the senors and rims just short of 2 years ago.  Is the battery already shot in the one sensor?  Any other suggestions?  I also updated the firmware a few days ago in the TS508.