With the Heljan model please ensure the directional lights are functioning correctly prior to decoder installation. We have found some models where bulbs are creating a `short` which can cause damage to the decoder.
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, two tone
F3. Horn 2, two tone
F4. Horn 3, single tone
F5. Buffer up
F6. Wheels on rail joint ‘clicks’
F7. Flange squeal
F8. Air tick
F9. Shunting mode, Press once the loco goes half speed, press it again and you are back to normal control.
F10. Acceleration/Deceleration speed over ride.