There are many reasons for this P0234 fault code to appear. However, the most common causes are:
The turbocharger or supercharger wastegate is sticking or damaged
Sticking wastegate control valve solenoid
The wastegate control hose is clogged
Defective or corroded connections or wiring to the boost pressure sensor
Faulty connections or wiring to the knock sensor
Bent rod from the discharge gate actuator to the discharge gate in the turbo
Faulty turbocharger boost sensor or actuator
