The Steptronic function makes it possible to shift all gears of the automatic transmission manually. The gear required by the driver is transmitted via three switches (to ground) in the manual gate to the AGS control unit: The "manual gate" switch is closed if the selector lever is moved out of the automatic gate into the manual gate. By pressing the selector lever forward or back, the "strike-up" or "strike-down" contact is additionally closed.
Note
After installing a new AGS control unit, the selector lever must be moved once into the "downshift" or "upshift" position with terminal 15 switched on in order for the control unit to detect that the Steptronic facility is installed.