Below is a list of the Function keys and their assignments applicable to this model. F0. Lights on/off F1. Sound on/off F2. Horn 1 F3. Horn 2 F4. Horn 3 F5. Buffer up F6. Coupling up F7. Flange squeal F8. Sander F9. Shunting mode. Press once and the loco moves slowly, press it again and you are back to normal control F10. Acceleration/Decel timing override. F11. Aux 1 F12. Aux 2