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. Coupling up F6. Guards whistle F7. Flange squeal F8. Spin engine with decompression 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