Welcome to the forum.
VAG Error Code: 17055
EOBD II Error Code: P0671
Fault Location:
Glow Plug Cylinder 1 (Q10) Circuit - Circuit malfunction
Possible Cause:
No Pre-Glow Period.
Poor Cold Starting.
Glow Plug Wiring faulty.
Poor connection.
Relay.
Glow plug control module.
Glow Plug faulty.
Engine control module (ECM).
Possible Solutions:
Check Glow Plug Wiring.
Check Glow Plug.
Special Notes:
See
TDIClub Glow Plug 101
VAG Error Code: 16786
EOBD II Error Code: P0402
Fault Location:
Exhaust gas recirculation (EGR) system - Excessive flow detected
Possible Cause:
Malfunction Indicator Light (MIL) ON.
Reduced Exhaust Gas Recirculation (EGR).
Reduced Power Output/Engine running rough.
Increased Emissions.
Hose leak/blockage.
Basic setting not carried out.
Exhaust Gas Recirculation (EGR) Flow restricted/clogged.
Exhaust Gas Recirculation (EGR) Valve stuck closed/leaking/faulty.
Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve faulty.
Exhaust Gas Recirculation (EGR) System faulty.
Possible Solutions:
Check/Clean Exhaust Gas Recirculation (EGR) System.
Check/Replace Exhaust Gas Recirculation (EGR) Valve.
Check Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve.
VAG Error Code: 16512
EOBD II Error Code: P0128
Fault Location:
Coolant thermostat - Coolant temperature below thermostat regulating temperature
Possible Cause:
Mechanical fault.
VAG Error Code: 17964
EOBD II Error Code: P1556
Fault Location:
Charge Pressure Control - Negative deviation
Possible Cause:
Reduced power output.
Limp mode.
Boost Pressure too Low.
Hoses/Pipes incorrect connected, disconnected or leaking.
Charger Pressure Control defective.
Variable Nozzle Turbo (VNT) 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.
As taken from my
Free EOBD II Error Codes software