Bike interface OBD

Hey guys, I'm working on acquiring RPM, TPS and ECT from my Yamaha 2019 bike (MT09/Tracer):
on the bike there is a DLC connector where I'm get connected on the CAN bus with MCP2515 module... I can read lot of CAN messages but since it support also the OBDII protocol I'm asking for the OBD PIDs and now I can succesfully get RPM and ECT (the value match the dashboard!) but I'm not sure about the TPS:
my bike has the ride by wire and I'd like to read the real TPS not the throttle/handle position because if I open full throttle the ride by wire may not open fully the "real throttle"... hope make sense for you.
In short: I'm asking the ODB PID 0x11 for Throttle position as described also in Wikipedia but I'm getting 14% value with throttle fully closed and aroound 28% at fully open (engine off). If I start the engine I'm getting 14% at idle and if I lightly open the throttle it get incresed but can't test at full gas...
The formula I use is simply : float tps = (100.0 / 255.0) * rxBuf[3];

Can you help me understand? I was expected 0% at least at fully closed