Under the microscope: fully power-adjustable trailer coupling: Hitch up a trailer easier than ever before

Sep 13, 2016

The E-Class features a fully power-adjustable trailer coupling for the first time. A push of a button is all it takes to extend or retract the otherwise concealed coupling. Another new feature is the enhanced ball coupling for secure mounting of a cycle rack.

Previously the E-Class Estate has featured a trailer coupling that remained concealed when not in use, which was unlocked using a hand lever in the load compartment but still had to be engaged by hand and then folded back in after use. The process is now much easier: pressing a button in the tailgate or driver's door extends the ball coupling part of the trailer coupling electrically and secures it in the operating position automatically. After use it retracts back into its idle position behind the bumper equally effortlessly. Vehicles with trailer coupling are equipped with ESP® trailer stabilisation as standard.

When the trailer coupling is being moved out, the indicator lamp in the pull button flashes, and this is indicated in the instrument cluster until the locking process is complete. If the ball coupling is not locked, a warning signal sounds, and a warning message appears on the instrument cluster display. The socket for establishing a power connection between the towing vehicle and the trailer is located on the side in the ball coupling part of the trailer coupling to make it easily accessible. To ensure a long service life, the ball coupling has a zinc/nickel coating to protect against corrosion.

To prevent any misuse by children, the button in the tailgate is inaccessible when the tailgate is closed and is out of reach from children when the tailgate is open. For additional safety, the trailer coupling has an obstruction sensor similar to the one for the power windows. To prevent incorrect operation due to snagged items of luggage, a pull switch is used instead of a pushbutton.

If the reversing camera is specified (standard with Parking package and Parking Pilot, optional in conjunction with Audio 20 USB), additional guide lines and an additional zoom mode are displayed to make it easier to control and hitch up the trailer. In zoom mode, the trailer is shown from a bird's-eye view. It is therefore even easier for the driver to control the trailer drawbar.

World first: new holding device for cycle racks

Exceptionally secure and easy to fit, the holding device for cycle racks is a world first. The trailer coupling has two extra bolts on the ball coupling to support a suitable cycle rack safely. This design allowed the load-carrying capacity to be increased to 100 kg and four cycles - particularly useful in the case of e-bikes, which could previously only be carried to a limited extent. Previous racks can still be used, although these remain limited to carrying three cycles and 75 kg.