I did mine yesterday, after goosing around in the dashboard where I shouldn't have been.
The trick is to ride 18 km/h +/- 2 km/h for a while so the system has recalibrated. This is not easy to do, maintaining that tolerance of speed is tricky (to me). Finding a road without holding up other vehicles locally is not easy either.
I never seem to observe that the calibration has completed. I just switch the motor off for 30 seconds, turn the ignition back on, and select one of the traction control modes. If it has calibrated correctly, it will be available, otherwise try again.