2008 Ford Expedition Owner Guide 1st Printing - Page 278

Driving If the steering wanders or pulls, check for: Underinflated tire(s) on any wheel(s) Uneven vehicle loading High crown in center of road High crosswinds Wheels out of alignment Loose or worn suspension components Variable assist steering Your vehicle is equipped with variable assist power steering. At low engine RPM, steering assist will adjust to reduce efforts and improve low speed maneuverability. At high engine RPM, the assist will adjust to improve steering feel at high speeds. If the amount of effort required to steer your vehicle changes while driving at a constant engine RPM, have the power steering system checked by your authorized dealer. AIR SUSPENSION SYSTEM (IF EQUIPPED) The air suspension system is designed to improve ride, handling and general vehicle performance during: • Certain road conditions • Steering maneuvers • Braking • Acceleration This system keeps the rear of your vehicle at a constant level by automatically adding air or releasing air from the springs. If you exceed the load limit, the rear air suspension may not operate. The air suspension system will stay active for 40 minutes after the ignition is turned off to accommodate any load changes. (The air compressor may run when the vehicle is off; this is normal.) The air suspension system can be enabled or disabled through the message center. Refer to Message center in the Driver Controls chapter. If the system is off, the rear air suspension will not operate and will not raise (pump) or lower (vent) while the vehicle is not moving. However, if the system determines that the vehicle is low or high and needs to make a height adjustment while driving at speeds above 15 mph (24 km/h), the system will pump or vent as required. Normal vehicle operation does not require any action by the driver. 278 2008 Expedition (exd) Owners Guide (post-2002-fmt) USA (fus)