What is this and what does it do?

Thanks

 

Kick down by deffinition is the car down shifting to a lower gear to give you more acceration when you step on the gas.

Basically, your driveing along with the car in "D" (drive) or "S" (sport mod), {it dosent kick down when your in tiptroinc mode}. so your driveing along like I said in D or S, and you want to pass some one or for what ever reason you want to accelerate faster than the car will in the gear its in so it "Kicks down" a.k.a "down shifts" to a lower gear giveing you more acceleration.

The car "Kicks down" because when your cruiseing along to save gas and keep RPM's down, the audi will automatically put its self in its top gear weather you have a five speed or six speed. So to accelerate fast it has to kick down.

 

Kick down is the car shifting down more than one gear to provide an increase in acceleration commeasurate with the amount you have pressed the gas pedal. There is a kick down switch under your gas pedal which tells the ECU to do this.