P1550 OBD Code Definition:
P1550 Idle Speed Control valve Closing Solenoid Control Circuit Electrical
P1550 OBD Code Description:

Possible Symptoms

• Malfunction Indicator Light (MIL) ON
• Engine misfiring/juddering/running rough
• Power Loss / Limp Mode

Possible Causes

• Hoses/Pipes incorrectly connected, disconnected, blocked or leaking
• Charger Pressure Control faulty
  • Solenoid Valve for Boost Pressure Control faulty
  • Turbocharger faulty
  • Vacuum Unit for Turbocharger faulty

Possible Solutions

• Check Hoses/Pipes to/between Components
• Check Charge Pressure Control
  • Check Solenoid Valve for Boost Pressure Control
  • Check Turbocharger
  • Check Vacuum Unit for Turbocharger