Coupling up a trailer

Do not connect the trailer's brake system (if featured) to the hydraulic brake system of the towing vehicle, as the latter is equipped with an anti-lock brake system.

Doing so will result in a loss of function of the brake systems of both the vehicle and the trailer.

■ Make sure that the automatic transmission is set to position P.

■ Apply the vehicle's electric parking brake.

■ Start the engine.

■ Vehicles with the AIRMATIC package: select highway level.

■ Vehicles with ADS: set ADS to AUTO or COMF.

■ Switch off the engine.

■ Close all doors and the tailgate.

■ Couple up the trailer.

■ Establish all electrical connections.

■ Check that the trailer lighting system is working.

Vehicles with the AIRMATIC package: with a trailer attached, the vehicle will always remain at highway level. When coupling up a trailer, please observe the following:
• Unless highway level has been set manually, the vehicle is automatically lowered to highway level. This is the case if a speed of 5 mph (8 km/h) is reached.

• High-speed level is not available.

These restrictions apply to all accessories powered through a connection to the trailer power socket of your vehicle, e.g. a bicycle carrier.

Observe the maximum permissible trailer dimensions (width and length).

Most U.S. states and all Canadian provinces require by law:
• Safety chains between the towing vehicle and the trailer. The chains should be crosswound under the trailer drawbar. They must be fastened to the vehicle's trailer coupling, not to the bumper or the axle.

Leave enough play in the chains to make tight cornering possible.

• A separate brake system for certain types of trailer.

• A safety switch for braked trailers. Check the specific legal requirements applicable to your state.

If the trailer detaches from the towing vehicle, the safety switch applies the trailer's brakes.