Mercedes-Benz S 450 4MATIC Operator's Manual page 479

Controls in detail
Driving systems
Park Assist is automatically activated
when the engine is running and the trans-
mission is in drive position D, reverse
gear R or neutral position N.
The Park Assist system deactivates at
speeds over approximately 10 mph
(16 km/h). At lower speeds the Parktronic
system turns on again.
Park Assist is also switched off when you
set the automatic transmission to P or
switch off the engine.
While the transmission is in neutral
position N, Park Assist is switched off if
you secure the vehicle in place with the
electronic parking brake.
The Park Assist system monitors the sur-
roundings of your vehicle with four sensors
in the front bumper and two sensors in the
rear bumper.
478
Range of the sensors
The sensors of the Park Assist system are
integrated in the front and rear bumpers.
Make sure that the bumpers are clear of
dirt, ice and slush in the area of the sen-
sors, as otherwise, Park Assist may not
function properly, see "Cleaning the driv-
ing systems sensors" ( page 620).