[Tatsfield]

Are you using a VIDA/DiCE? Trying to second guess modern electronic controlled cars by symptoms alone is like trying to swat flies with a banana! VIDA should tell you what faults the ECU is logging for itself. Technical assistance on this forum should be limited to how to fix a known fault that has been diagnosed by VIDA, not us all having guesses from a long list of possibles that may be similar to something that once happened to our cars. Sorry to sound harsh but the times are changing and electronics have both hindered and helped DIY car repair and maintenance. Today DIY Volvo owners buy themselves a VIDA/DiCE and help others to help them.