ABS light on, VDC light off, slip, four-wheel drive does not engage?

The most common item that causes this is a bad ABS controller and it can lock out the rest of those items because the VDC and four-wheel drive use the same sensors and signals for traction control. The first step would be to get the truck scanned to see what codes are set and to turn the light on. It is possible it is something like a wheel speed sensor or bad connection but having the codes gives a road map to start with. Some of the chain parts stores will scan for engine/ABS codes for free.