Volvo All Engines (2017 Emissions) Fault Code: P004591 PID: EMS Turbocharger/Supercharger Boost Control “A” Circuit / Open

The (VGT) Variable Geometry Turbocharger Actuator is a self-contained component with motors, sensors and a control unit.
The (VGT) Variable Geometry Turbocharger uses a movable nozzle to adjust the intake manifold pressure for various operating conditions. Nozzle movement is controlled by an actuator mounted on the tubocharger. When the Engine Control Module (ECM) Relay is energized, a fuse supplies battery voltage to the (VGT) Variable Geometry Turbocharger and the unit is grounded by means of the engine block.

Conditions for diagnostic trouble code (DTC):
1) Initiation phase detected for more than 15 s

Observable symptoms
1) None

Probable cause
1) Internal or external blockage
2) Y54: Variable Geometry Turbo
3) Turbo nozzle binding due to soot or damaged turbo