System self-test
The 42 indicator lamp illuminates when you:
• turn the SmartKey to position 1 or 2 in the
ignition lock
• on vehicles with KEYLESS-GO, press the
Start/Stop button once or twice
The 
indicator lamp goes out
again after approximately six seconds.
If the indicator lamp does not
illuminate or is lit continuously, the system is
malfunctioning. Have the BabySmart™
system checked at an authorized Mercedes-
Benz Center before transporting a child on
the front-passenger seat.
For further information, see "Problems with air bag deactivation system".
WARNING 
Do not place powered-on laptops, mobile
phones, electronic tags such as those used in
skipasses or similar electronic devices on the
front passenger seat. Signals from such
devices may interfere with the BabySmart™
air bag deactivation system. Such signal
interference may cause the
indicator lamp not to come on during self-test.
The + SRS indicator lamp and/or the
indicator lamp could be
continuously lit, indicating that the system is
not functioning. The front-passenger front air
bag could deploy inadvertently or fail to
deploy in an accident.
See also:
Checking the oil level using the oildipstick
When checking the oil level:
• park the vehicle on a level surface.
• the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
Example: ...
EASY-ENTRY/EXIT feature (third rowof seats)
Important safety notes
WARNING
To help avoid personal injury, the second-row
seat backrests must be properly locked either
in the upright position or, when using the
expanded cargo vo ...
Important safety notes
If you fail to adapt your driving style, the
driving safety systems can neither reduce the
risk of accident nor override the laws of
physics. Driving safety systems are merely
aids designed to ...