See also:

High outside temperatures
If DEF heats up to over 122 °F (50 °C) for extended periods, e.g. as a result of direct sunlight on the DEF reservoir, DEF can decompose. Ammonia vapors develop as a result. WARNING When o ...

Problems with your vehicle
If you should experience a problem with your vehicle, particularly one that you believe may affect its safe operation, we urge you to contact an authorized Mercedes-Benz Center immediately to h ...

Tire tread
WARNING Although the applicable federal motor vehicle safety laws consider a tire to be worn when the tread wear indicators (TWI) become visible at approximately 1/16 in (1.6 mm), we recomm ...