Mercedes-Benz E-Class Saloon Owner's Manual page 241

Driving systems
238
Towing a trailer
! Fold in the ball coupling if the trailer tow
hitch is not required. PARKTRONIC meas-
ures the minimum detection range to an
obstacle from the bumper, not the ball cou-
pling.
PARKTRONIC is deactivated for the rear area
when you establish an electrical connection
between your vehicle and a trailer.