It took two NUC5i5RYK Intel boards getting smoked while I tried to test the pinouts for my project but I figured it out. Looking at the image above, the pins are #1,2,3,4 from left to right (right being closest to the black screw). The pinouts are below.
Pin signal name descriptive name
1 +5VSB 5V
2 PCH_GPIO24 Power draw sensor
3 GND Ground
4 +VIN 12volt to 19v DC input
You do not need to use pins one and two if you are building an aux power connector like we are. In my case, i am building on onboard UPS system for an IFE system remote operation.