I have a 2005 Chevy Tahoe. The driver side forward/back functions has stopped working. The same button controls the tilt of the bottom part of the seat and is working fine. The button that control the tilt of the back of the seat is also fine. I have looked to see if something might be jammed in the track but didn't see anything. The seat heater works and the passenger side seat is also fine. Any ideas?

Try spraying the button with WD-40. If that doesn't work, you'll need to tear into it and see where the problem is.

The fore/aft motor is different than the tilt/recline motor. And the portion of the control switch is different, too.
Have you worked with electrical schematics before?