It’s been a while since I hooked my AEM up but the white wire is the power logger input and I think I grounded the brown wire at the ground on the I/O board.
Maybe I’m not understanding the instructions but since the gauge has a separate ground wire I read this as the analog output should be connected this way.
Red is switched power, black chassis ground, brown sensor ground and white is the 5v signal that goes to the wb input of the i/o board for the pl. Other 3 wires not used. According to the instructions they want the bung 18" away from the turbo too.