I have a 2005 volvo S40 - diesel. Using a general diagnostic scanner the fault code P 0234. - ref boost pressure - the car won't rev over 3000 rpm.

The turbo pipes are all connected with no signs of cracks etc. no sign of oil leaks and I can open and close the waste gate by levering the rod.

Can anybody forward the electronic component checks and perhap the actual value/ measured value blocks targets for air mass, air temperature etc. etc. etc. as I can read them on the scanner but I have no reference values.

many thanks,

Cowenstaff.