17964/P1556/005462
From Ross-Tech Wiki
17964/P1556 - Charge Pressure Control: Negative Deviation
Possible Symptoms
- Reduced power output
- Limp mode
Possible Causes
- Boost Pressure too Low
- Hoses/Pipes incorrect connected, disconnected or leaking
- Charger Pressure Control defective
- VNT (variable nozzle turbo): nozzles stuck
- Solenoid Valve for Boost Pressure Control (N75) defective
Possible Solutions
- Check Hoses/Pipes to/between Components
- Check Solenoid Valve for Boost Pressure Control (N75)
- Check / Clean / Replace Charge Pressure Control
- Check / Clean mechanism for variable nozzles