2009 Ford Expedition Owner Guide 2nd Printing (Spanish) - Page 778

Driving Normal characteristics On some four-wheel drive models, the initial shift from two-wheel drive to four-wheel drive while the vehicle is moving can cause some momentary clunk and ratcheting sounds. This is the front drivetrain coming up to speed and engaging the front wheels, and is not cause for concern. Sand When driving over sand, try to keep all four wheels on the most solid area of the trail. Avoid reducing the tire pressures but shift to a lower gear and drive steadily through the terrain. Apply the accelerator slowly and avoid spinning the wheels. Note: If air is released from your tires, the Tire Pressure Monitoring System (TPMS) indicator light may illuminate. Avoid excessive speed because vehicle momentum can work against you and cause the vehicle to become stuck to the point that assistance may be required from another vehicle. Remember, you may be able to back out the way you came if you proceed with caution. If your vehicle is equipped with AdvanceTrac௡ with RSC, press the AdvanceTrac௡ with RSC button (refer to AdvanceTrac௡ with Roll Stability Control (RSC) Stability Enhancement System in this chapter) while driving in deep sand if you experience excessive engine power reduction. Mud and water If you must drive through high water, drive slowly. Traction or brake capability may be limited. When driving through water, determine the depth; avoid water higher than the bottom of the hubs (if possible) and proceed slowly. If the ignition system gets wet, the vehicle may stall. Once through water, always try the brakes. Wet brakes do not stop the vehicle as effectively as dry brakes. Drying can be improved by moving your vehicle slowly while applying light pressure on the brake pedal. Be cautious of sudden changes in vehicle speed or direction when you are driving in mud. Even four-wheel drive vehicles can lose traction in slick mud. As when you are driving over sand, apply the accelerator slowly and avoid spinning your wheels. If the vehicle does slide, steer in the direction of the slide until you regain control of the vehicle. 315 2009 Expedition (exd) Owners Guide, 2nd Printing USA (fus)