I got a 2003 g35 coupe auto and it has a flashing at check light (no check engine light or codes) it flashes 16 times indicating the tcm isn’t receiving a engine speed signal the car also feels like it’s stuck in a higher gear not sure where to start checking if anyone knows where I should start.

The "high gear" means the tranny is stuck in limp mode, and if you don't have a lit MIL along with it, the TCM may have a CAN communication issue. That situation usually happens when the ECM goes limp and stops transmitting a tach signal, which lights the MIL and usually the slip/ABS lamps as well. Since you don't see those, you need to get it scanned and see if the TCM shows up, if it's absent then most likely it has a blown CAN driver or there's a problem with the CAN wiring.

Where is the can driver and wiring located? Thanks for the help

Inside the TCM, it isn't a separate part. The CAN wiring is in your Main Harness, wherever the wiring and harness diagrams say they are. No offense, but if you need to ask questions like those, have a shop look at it.

I’m getting voltage from the connector that connects to the tcm and it’s the two can wires that are providing a voltage, would that mean it’s a bad tcm? Or is there another test I should try