A “Busy” message during programming means that the system is temporarily busy. Simply try the task again. When the system is no longer busy, you will get a “Good” response. A “Fail” message during programming means that there is a problem with the locomotive on the programming track. Check to be sure the loco's wheels are making good contact with the programming track. Make sure that the decoder is properly installed in the locomotive. Make sure the connections to the programming track are secure. Make sure the programming track is powered.