That A symbol is for the eco idle, idling stop, pure drive or whatever you call it. It is set to 'On' by default and it basically cuts off your engine when your car comes to a stop. Releasing your brake pedal, moving your steering or the transmision stick would restart the engine automatically.remb, it wont work without your seatbelt in position.
Jerking could be due to bad fuel or a clogged filter and i dnt think that the language can be changed.