Glk350 eco mode

Here are some possible reasons: "There are multiple factors the on board computer looks at to decide if the Eco mode functions or not. Off the top of my head I remember engine temp, inside temp (ie if you are running the heater or air conditioner) and number of times it has activated ( so it does not turn on off over and over in rapid sequence like in a drive thru) are a couple of the things factored in. " and... ":The ECO engine stop only works when the battery is fully charged and the cabin temp is within a certain range of the set temp, both of which only occur after the car has been running a while." Personally, I can't stand it and shut it off with every start. ;-)