Starting procedure with the SmartKey
To start the engine using the SmartKey instead of KEYLESS-GO, pull the Start/ Stop button out of the ignition lock.
•► To start a gasoline engine: turn the SmartKey to position 3 in the ignition lock and release it as soon as the engine is running.
•► To start a diesel engine: turn the SmartKey to position 2 in the ignition lock.
http://strategic-human-resource.com/The 
preglow indicator lamp in the
instrument cluster lights up.
•► When the 
preglow indicator lamp
goes out, turn the SmartKey to position 3 and release it as soon as the
engine is running.
You can start the engine without preglow if the engine is warm.
See also:
Important safety notes
Have the batteries changed at a qualified
specialist workshop.
WARNING
Batteries contain toxic substances.
Swallowing batteries can lead to serious
health issues or death.
Keep batteries ...
Important safety notes
DSR assists you when driving downhill. It
keeps the speed of travel at the speed set on
the on-board computer. The steeper the
downhill gradient, the greater the DSR
braking effect on the vehi ...
PRE-SAFE® Brake
PRE-SAFE® Brake is only available in vehicles
with DISTRONIC PLUS.
Observe the "Important safety notes"
section.
PRE-SAFE® Brake can help you to minimize
the risk of a frontal colli ...