Here is a YouTube video describing the problem. If you throw this code, or your tranny goes into limp mode after a clunking shift at 2nd gear, and you basically stay in 3rd gear with no supercharger anymore, THIS is more than likely the issue. With a P0715 input shaft speed sensor code (mine was intermittent), either the speed sensor is cracked (the round cylinder on the right hand side), or contact is being lost (either permanently or intermittently) with the speed sensor contacts. See video that describes the problem.