Diesel Data: Automotive Repair

P1556

P1556

Note! Volkwagen does not refer to P1556 for the ALH engine in the Beetle, however on vehicle experience has shown that it is in fact a valid trouble code for this engine.

17964 P1556
Boost pressure regulation control limit exceeded

- Check wastegate bypass regulator valve per "Output Diagnostic Test Mode (DTM)" [1][2]Output Diagnostic Test Mode (DTM)