I am trying to retro fit an auto dimming mirror from a Lexus LS400. It has 4 wires; Red, Black, yellow, White

I assume the red is 12v+, black is ground, what is the yellow and white for? Its a basic mirror no compass or lights or garage opener. In the pictures the red is at one end of plug and black at the other end. Yellow and white are next to the black wire.

Circuit board
12+ Red
IL. NA
GND NA
AI white
+0 yellow
-0 Black

when I connect the red and black, it works as on off with the button. What makes the auto dim function?