2009 Volvo XC90 Owner's Manual - Page 145

06 Starting and driving Stability system Dynamic Stability Traction Control (DSTC) The stability system consists of a number of functions designed help reduce wheel spin, counteract skidding, and to generally help improve directional stability. NOTE • The message DSTC SPIN CONTROL OFF indicates that the stability system's spin control function has temporarily been switched off. The stability control indicator light will illuminate and remain on until spin control has been reactivated. The spin control function is automatically enabled each time the engine is started. functions are active. • • NOTE G028511 A pulsating sound will be audible when the system is actively operating and is normal. Traction control (TC) This function is designed to help reduce wheel spin by transferring power from a drive wheel that begins to lose traction to the wheel on the opposite side of the vehicle (on the same axle). TC is most active at low speeds. This is one of DSTC's permanent functions and cannot be switched off. Controls on the left-side steering wheel lever • DSTC ON indicates that all system Active Yaw Control (AYC) This function helps maintain directional stability, for example when cornering, by braking one or more of the wheels if the vehicle shows a tendency to skid or slide laterally. This is one of DSTC's permanent functions and cannot be switched off. Temporarily switching off Spin control 1. Turn the thumbwheel (1) on the left-side steering wheel lever until the DSTC menu is displayed. 2. Hold down the RESET button (2) to toggle between DSTC SPIN CONTROL ON or OFF. 06 Spin control (SC) The spin control function is designed to help prevent the drive wheels from spinning while the vehicle is accelerating. Under certain circumstances, such as when driving with snow chains, or driving in deep snow or loose sand, it may be advisable to temporarily switch off this function for maximum tractive force. WARNING The car's handling and stability characteristics will be altered if the DSTC system functions have been disabled. 145