My gpf light came on at 900 miles and it took me three tries over a week or so to get rid . I eventually got rid if it by doing a 30 mile run on the M60 in sport mode ,doing 70 but keeping the gear in 5th using the paddles. This was done 2 days on the trot , then the relief of no more light. Now I drive in normal ,not eco also I turn the isg off when I start the car and 500 miles later the cars running fine and mpg is starting to creep up again. Good luck sorting yours out .