Driving my 2003 S60 R with 120k on clock couple of days ago and engine stutter on motorway I have no power, boost or a message to indicate anything wrong, but my car drives as a normally aspirated car without turbo. On checking various forums I decided to replace the Boost Control Valve which is located on right side of airbox under the plastic square cover it costs under £40
and is a straight over swap - (firstly I disconnected the battery so as to reset ICU do not reconnect for 30 mins. - JOB SORTED ALL OK AGAIN.
Attachment 99699
Attachment 99700
Attachment 99701
Attachment 99702