2010 Mercedes ML-Class Owner's Manual - Page 257

Driving instructions The lowest value listed must be selected when determining how the vehicle and trailer are loaded. RThe tongue weight at the hitch ball must be 255 Observe maximum permitted trailer dimensions (width and length). Most states and all Canadian provinces require Rsafety added to the rear axle weight to prevent exceeding the rear Gross Axle Weight Rating (GAWR). The GAWR is indicated on the certification label located on the driver's door B-pillar (Y page 227). i The weight of other accessories, passengers and cargo will reduce the maximum trailer weight and tongue weight your vehicle can tow. Checking weights of vehicle and trailer RTo assure that the towing vehicle and trailer are in compliance with the maximum permissible weight limits, have the loaded rig (towing vehicle including driver, passengers and cargo, trailer fully loaded) weighed on a commercial scale. RCheck Ra Ra separate brake system at various trailer weights break-away switch on trailers with a separate brake system. Check with your local state laws for specific requirements. The switch activates the trailer brakes in the possible event that the trailer might separate from the tow vehicle. the vehicle's front and rear gross axle weight, the Gross Trailer Weight (GTW) and tongue weight. The values as measured must not exceed the weight limits listed under "Vehicle and trailer weights and ratings" (Y page 254). ! Do not connect a trailer brake system (if trailer is so equipped) directly to the vehicle's hydraulic brake system, as your vehicle is equipped with antilock brakes. If you do, neither the vehicle's brakes nor the trailer's brakes will function properly. i The provided vehicle electrical wiring harness for trailer towing has a brake signal wire for hook-up to a brake controller. X Coupling a trailer G Warning! Vehicles with air suspension program: While you are coupling or decoupling a trailer, make sure nobody locks or unlocks the vehicle and/ or opens or closes doors or the tailgate. The vehicle's level could change and you could endanger yourself and/or others as a result. Make sure that you do not operate the ADS switch or the vehicle level control system when coupling/decoupling the trailer. Make sure the automatic transmission is in park position P (Y page 110). X Engage the parking brake for the vehicle (Y page 107). X Start the engine (Y page 103). X Vehicles with vehicle level control: Select the highway level (Y page 156). X Vehicles with Adaptive Damping System (ADS): Set the ADS to AUTO or COMF (Y page 156). X Turn off the engine (Y page 108). Z Operation i Mercedes-Benz recommends loading the trailer in such a manner that it has a tongue weight between 8 % and 15 % of the GTW. chains between the towing vehicle and the trailer The chains should be criss-crossed under the trailer tongue. They must be attached to the hitch receiver, and not to the vehicle's bumper or axle. Make sure to leave enough slack in the chains to permit turning corners.