2010 Ford Expedition EL Owner Guide 3rd Printing - Page 319

Driving • If the vehicle goes from one type of surface to another (i.e., from concrete to gravel) there will be a change in the way the vehicle responds to a maneuver (steering, acceleration or braking). Again, avoid these abrupt inputs. Control Trac four-wheel drive system (if equipped) When a four-wheel drive mode is selected, the Control Trac system uses all four wheels to power the vehicle. This increases traction, enabling you to drive over terrain and road conditions that a conventional two-wheel drive vehicle cannot. Power is supplied to all four wheels through a transfer case. On four-wheel drive vehicles, the transfer case allows you to select four-wheel drive when necessary. Information on transfer case operation and shifting procedures can be found in this chapter. Information on transfer case maintenance can be found in the Maintenance and Specifications chapter. You should become thoroughly familiar with this information before you operate your vehicle. 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. 319 2010 Expedition (exd) Owners Guide, 3rd Printing USA (fus)