Mercedes-Benz Black Series Operator's Manual page 138

Driving systems
136
Switching on Blind Spot Assist
Make sure that Blind Spot Assist
X
( page 145) is activated in the on-board
Y
computer.
Ensure that key position 2 has been
X
selected with the Start/Stop button.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.