Gear shift not displaying on instrument panel?

Hello, The instrument cluster receives this information over the vehicles LAN (think intranet for the vehicle). The transmission control module (TCM) sends this information based on the transmission position sensor or the transmission range selector (shifter) position. If this information is failing to make it to the transmission control module, you would likely not be able to select any drive range, so it is most likely a fault of the instrument cluster or wiring harness. Unfortunately, you will need diagnostic testing to find the issue.