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 ...

DEF
Important notes on use To function properly, BlueTEC exhaust gas aftertreatment must be operated with the reducing agent DEF. Adding DEF is one of the tasks performed during maintenance. Under no ...

Important safety notes
WARNING When leaving the vehicle, always remove the SmartKey from the ignition lock. Always take the SmartKey with you and lock the vehicle. Do not leave children unsupervised in the vehic ...