My 2010 TL AWD started showing a message of Check Emission Systrm filled by Check Transmission system with the blinking D. The only code in the care was for the transmission range switch. After changing that, the code did not clear and I figured I had a defective part. I took that one back and purchased a more expensive one from another store. Put it in and the codes still didn't clear. Then I noticed with the car not running but push start on so that lights and everything is on, I could here a small tapping/knocking noise near the range switch. I can't decipher what it is or what to check. PLEASE HELP!!! Anyone ever have this issue?? Could it be some of the solenoids going bad, wiring harness, etc.