P1557 OBD Code Definition:
P1557 Charge Pressure Contr. Positive Deviation
P1557 OBD Code Description:

Possible Symptoms

• Reduced power output
• Limp mode

Possible Causes

• Boost Pressure too High
• Hoses/Pipes incorrect connected, disconnected, blocked or leaking
• Charger Pressure Control defective
  • VNT (variable nozzle turbo): nozzles stuck
• Solenoid Valve for Boost Pressure Control  defective

Possible Solutions

• Check Hoses/Pipes to/between Components
• Check Solenoid Valve for Boost Pressure Control
• Check / Clean / Replace Charge Pressure Control
  • Check / Clean mechanism for variable nozzles