Fault code P0243 – a step-by-step guide to diagnosing and fixing it

Error code P0243 is displayed and the check engine light is on - what does this mean?

The DTC P0243 is stored by the OBD system when a problem with the turbocharger wastegate solenoid valve circuit A is detected. This trouble code indicates that the control unit has detected a malfunction in the wastegate control circuit of the turbocharger. For various manufacturers, this fault code may also be referred to as "turbocharger bypass valve circuit A".

What causes can this fault code have?

• Defective wastegate solenoid valve
• Damaged wiring to the wastegate valve
• Corroded or loose plug connections
• Defective vacuum hoses to the turbocharger
• Mechanical defect on the wastegate servomotor
• Clogged or damaged wastegate actuator
• Faulty ground connection in the control circuit
• Defective engine control unit (ECU)

What symptoms occur in parallel with fault code P0243?

• Loss of power: Significantly reduced engine power, especially at higher engine speeds
• Excessive boost pressure: Unusually high boost pressure due to defective wastegate
• Starting problems: Difficulty starting the engine or rough idling
• Black smoke: Dark exhaust fumes due to excessively rich fuel/air mixture
• Whistling noises: Unusual noises from the turbocharger area
• Emergency running program: Vehicle switches to safety mode with limited power

How can the problem with error code P0243 be rectified?

• Repairing EOBD code P0243 requires a systematic approach to identify the source of the fault.
• Complete inspection and replacement of the wastegate solenoid valve including wiring and plug connections
• Replacement of all damaged vacuum hoses and inspection of the vacuum supply to the turbocharger system
• Cleaning or replacing the wastegate actuator and checking its mechanical mobility
• Repair of the wiring in the entire wastegate control circuit and replacement of corroded plug connections
• Checking and repairing the ground connections in the turbocharger control system
• For electronic defects: Replacement or reprogramming of the engine control unit