Not sure if it has a decoder installed. Quite frankly I'm not even sure what a decoder is. From doing a little research on it I see that analog engines are set to function 10 on the ez command 

Hi everybody,
     Pretty new to model railroading. I have a basic setup using the ez command controller. I recently purchased the Acela train set to add to out collection. I bought it used. It can with a large black analog controller. It says it is dcc equipped. When I hook up the analog controller it works like it should. When I hook up the ez command controller the engine is set to program button 10. From what I have read all Bachman trains are set to program button 3. It moves very slow and the sounds are very quiet. I don't think the lights operate properly. When you turn the speed up the lights dim. I have read and watched all the videos on how to program the controller but I can't seem to get the engine programmed to another number. That was my first idea in trouble shooting the problem. Any help would be appreciated. My 6 year old is devastated it doesn't work right.