A correct tire dimension must be programmed to get the vehicle speed signal correct. The programming is performed in Engine control module (ECM) and Main instrument unit (MIU). Check if there is any fault codes in ECM and MIU if it is impossible to perform the programming.
Procedure
Press the OK button. Programmed tire size is displayed.
To perform programming press OK and choose tire size, choose cancel to abort the programming.
After succeded programming is the new tire size displayed.