See also:

Tire identification marks
Tire size 255/50 R 19 103 Y 255: nominal width in mm 50: aspect ratio in % R: radial tire code 19: rim diameter in inches 103: load rating, not for ZR tires Y: speed rating, before the R on ZR ...

Activating HDC
Press the button; the LED above the button lights up. ...

Switching off automatically
The system switches off and the LED goes out: ▷ After approx. 165 ft/50 m when driving forward. ▷ After approx. 22 mph/35 km/h when driving forward. Switch on the system again if nece ...