4-Wheel Drive - 4WD LOW
WARNING: This page is about a different car, the 2002 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
4WD LOW allows for maximum pulling capacity. Shifting into 4WD LOW causes the range sleeve to move rearward and engage the planetary gear to achieve gear reduction. The result is that the output shaft now turns more slowly than the input shaft. This action increases the pulling capacity available to the wheels.