Auto-dimming Mirror Wiring Question

I recently picked up a Gentex-209 Auto-dimming rearview mirror from an Audi A6. I've been able to figure out the wiring from searching the forum except for Pin 6 (Green wire on the mirror side). What is this wire used for?

Did you see MOGolf's how-to thread?

Yes, MOGolf's was one of several I viewed and printed out for reference. On MOGolf's (the diagram on page 10) it shows a T6a connector w/no pin 6 and a T4a connector for the rain sensor which the A6 did not have, but the T6a confirms with others that pins 1-3 are the power and ground. The Gentex/Mito website wasn't much help

All you need is power and ground for the A6 mirror to function, other wires are for driver/passenger door auto dimming and reverse lockout.


Bajan