P1556
P1556Note! 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)