Fireline seems to take pleasure in being given messages to give and objects to retrieve or find. Give him a job and he'll happily do it... most the time.
His history is mostly unknown, except that a Desepticon had found his form along the dead and dying within the scrap fields upon a cybertronain occupied planet. Instead of offlineing him, the mech deciding to take him upon the ship to repair and restore him to a functioning order. Since then, he will quiet often wonder the ship and surrounding places for things to do, sometimes even appearing in the most unusual spots.
It is unknown whether he is fully Decepticon aligned though.