Seat altea, does not turn on

Hello I have a Seat Altea 2.0, which has been giving problems since it works wonderfully except for some occasion that without more or more stops on. In which case the mechanic arrives put the scanner and fly to turn on, but now I was driving and simply turned off, the mechanic that perhaps is the camshaft sensor is told since when trying another on, but suddenly it marks
and that the indicated scanner fails in the VGR valve. So I would like to know if someone has an idea that it is happening or could send me the Seat Altea 2.0 service manual, thank you !!!!