Hi Nino,
The error codes No 206 and 208 => The speed sensor of the traction/drive motor is faulty.
=> Please check the wirings from the speed sensor to the power module. it normally has 4 wires : 2 for power supply & 2 for signal feedback.
=> Remove the speed sensor then clean it as well as check the gap between the sensor to the motor shaft.
=> Replace the new sensor.
Cheers