My power tilt on driver seat of my GMC Terrain wasn't working. The fix is to test the switches on the side of the seat. That can be accomplished by prying off the side cover and checking continuity on the switch bar. That bar of switches is very cheap, under $20.00 so it might be the first to replace. The power tilt is in the back of the seat. You have to remove the hard plastic cover on the back of the seat. That will give you access to the motor for the power tilt. If you can find or rig up a 12Volt battery you can connect it to the positive and negative leads on the motor. This way you can test the motor independently of any wiring or switches. In fact you can use this technique to check all the motors (forward/backward/tilt). It turned out in my case it was the switch. The motor tested fine. Search driver side GMC Terrain switch and you can find it for cheap on the web. Hopefully this info helps someone else.
