Auto Turn On And Off For Garmin Nuvi 255w?

I received the Garmin Nuvi 255 fr Christmas and when I first used it, it would automatically turn on when I turned my car on (as the power cord was turned on) and then when the car was shut off, it would display “turn off or stay on, and would automatically turn off in 30 secs. Its just all the sudden stopped doing that. Is there a way to set it back up to turn on and off automatically????