2003 GMC Yukon Owner's Manual - Page 300

_ (4 Wheel Steer tow mode): When towing a trailer the 4 wheel steer tow mode provides enhanced stability allowing the trailer to follow the path of the tow vehicle more closely, especially during lane changes. In this mode the system operates much like the 4 mode, but is enhanced for trailer towing. It is recommended for all types and weights of trailers. To engage the 4 Wheel Steer tow mode, press the button until the 4 and tow mode indicators light up on the instrument panel. If the tow indicator is flashing you will have to center the steering wheel by turning it to the left or right. While in the 4 wheel steer tow mode, it is possible the steering wheel may be slightly off center. For more information, see Towing a Trailer on page 4-61. Higher Speeds (40 m.p.h./64 km/h, and above) At higher speeds the front and rear wheels will turn in the same direction. This improves stability of the vehicle during lane changes and sweeping turns. 4-18