Mercedes-Benz 2011 R-Class Operator's Manual page 52

Occupant safety
50
System self-test
The 42 indicator lamp
illuminates when you:
turn the SmartKey to position 1 or 2 in the
R
ignition lock
on vehicles with KEYLESS-GO, press the
R
Start-Stop button once or twice
The 42 indicator lamp goes out
again after approximately six seconds.
If the 42 indicator lamp does not
illuminate or is lit continuously, the system is
malfunctioning. Before transporting a child
on the front-passenger seat, have the
BabySmart™ system checked at an
authorized Mercedes-Benz Center.
For more information, see "Problems with the
air bag deactivation system" section
( Y page 51)
G
Warning
Do not place powered-on laptops, mobile
phones, electronic tags such as those used in
ski passes 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 42
indicator lamp not to come on during self-test.
The + SRS indicator lamp and/or the
42 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.