Hyundai Repair: CODE P0715, hyundai elantra, turbine speed

Question
What and where is the Input/Turbine Speed Circuit A  I have a 2001 Hyundai Elantra and this code comes up.  While driving it slips into 2nd or 3rd gear and stays there and the check engine light comes on.  Is this an after market item and is it easy to replace ourselves?  Can you give me the part number?

Answer
Hi, Vickie.  In nearly every instance I've seen this code, it has been due to a failure in the input sensor itself.  

I've no idea whether you can purchase it anywhere other than the dealer.  If you'd like to purchase it from your local Hyundai or Kia dealer, the part number will be 42620-39051.

The replacement is relatively simple.  Remove the lid from the air box, remove the filter, and remove the three screws holding the bottom of the box in place.  Then, remove the air box.  Next, unbolt the two 12mm bolts holding the shift cable bracket in place.  This will allow you to then move the bracket to the side and remove the sensor underneath it, held in by one 10mm bolt.  Do your best to clean around the sensor so nothing drops in the transmission.  Then twist and remove the sensor after removing the 10mm bolt.  Once you've got it pulled up where it's easy to work with, unplug it from the wiring.  Then simply install the new sensor, bolt it down, and plug it in.  And last, reinstall/reattach everything you've taken apart.