I had one years ago. Someone had turned the switch to off so it wouldn't shift so I got it cheap. Turned it back on and it worked.
I've had other "automatic" bikes (Autobikes, Landriders, Huffy Savanah) and this one does work better than any other. Shifting is pretty quick. Just suffers from the same problem as all other automatics, it shifts when it wants, not when you want. The all mechanical automatics grind between gears so on those you learn to ride at certain speeds. Up hills are a problem. Works best if you slow down at the bottom of the hill and ride a steady pace so it doesn't shift under load with out warning. Rapid stops can leave the automatics in a higher gear so it tries to down shift while you are starting up again.

IMO, Trek spent far too much on designing this line of Lime bikes. Overpriced for what you got new. The color accent kits were pointless. It was all about style. I found the ergonomics of the bike were a bad fit for me. Too upright and a short cockpit. Technically interesting but not a good rider for me so I sold it.

There is a small hole in the servo box where you can access the mode switch. Off, early shifting, normal, delayed, etc.