Checking the turbocharger (TC) function with the control system disengaged

Fig 1: Locating Wastegate To Control Valve Hose

Courtesy of VOLVO CARS OF NORTH AMERICA.

Disconnect the hose between the wastegate and the control valve.

Manual transmission  : Accelerate in 3rd gear at wide open throttle (WOT). Read off the boost pressure value.

Automatic transmission  : Accelerate in 2nd gear. Do not engage kickdown  . Read off the boost pressure value when it has stabilized.

If the wastegate has stuck in the open position, the boost pressure will be less than 0.5 bar, 60-65 kPa.

If the wastegate has stuck in the closed position, the boost pressure will be higher than 0.5 bar, 60-65 kPa.