2007 GMC Acadia Owner's Manual - Page 339

The traction control system may activate on dry or rough roads or under conditions such as heavy acceleration while turning or abrupt upshifts/downshifts of the transmission. When this happens, you may notice a reduction in acceleration, or may hear a noise or vibration. This is normal. If your vehicle is in cruise control when the system activates, the StabiliTrak® light will flash and the cruise control will automatically disengage. When road conditions allow you to use cruise again, you may re-engage the cruise control. See Cruise Control on page 180. StabiliTrak® may also turn off automatically if it determines that a problem exists with the system. If the problem does not clear itself after restarting the vehicle, you should see your dealer/retailer for service. All-Wheel Drive (AWD) System If your vehicle has this feature, engine power is sent to all four wheels when extra traction is needed. This is like four-wheel drive, but there is no separate lever or switch to engage or disengage the front axle. It is fully automatic, and adjusts itself as needed for road conditions. When using a compact spare tire on your AWD equipped vehicle, the AWD system automatically detects the presence of the compact spare and the AWD is disabled. To restore the AWD operation and prevent excessive wear on the clutch in your AWD system, replace the compact spare with a full-size tire as soon as possible. See Compact Spare Tire on page 477 for more information. 339