2009 Mercury Mariner Owner's Manual - Page 212

Driving If your vehicle gets stuck in mud or snow If your vehicle gets stuck in mud or snow, it may be rocked out by shifting between forward and reverse gears, stopping between shifts in a steady pattern. Press lightly on the accelerator in each gear. Do not rock the vehicle if the engine is not at normal operating temperature or damage to the transmission may occur. Do not rock the vehicle for more than a minute or damage to the transmission and tires may occur, or the engine may overheat. REVERSE SENSING SYSTEM (IF EQUIPPED) The Reverse Sensing System (RSS) sounds a tone to warn the driver of obstacles near the rear bumper when R (Reverse) is selected and the vehicle is moving at speeds less than 3 mph (5 km/h). The system is not effective at speeds above 3 mph (5 km/h) and may not detect certain angular or moving objects. WARNING: To help avoid personal injury, please read and understand the limitations of the reverse sensing system as contained in this section. Reverse sensing is only an aid for some (generally large and fixed) objects when moving in reverse on a flat surface at "parking speeds". Inclement weather may also affect the function of the RSS; this may include reduced performance or a false activation. WARNING: To help avoid personal injury, always use caution when in reverse and when using the RSS. WARNING: This system is not designed to prevent contact with small or moving objects. The system is designed to provide a warning to assist the driver in detecting large stationary objects to avoid damaging the vehicle. The system may not detect smaller objects, particularly those close to the ground. WARNING: Certain add-on devices such as large trailer hitches, bike or surfboard racks and any device that may block the normal detection zone of the RSS system may create false beeps. 212 2009 Mariner (mrn) Owners Guide, 2nd Printing USA (fus)