Some Volkswagen error codes are 16599-P0215 (engine overspeed condition), 17704-P1296 (cooling system malfunction), 18274-P1866 (data bus powertrain missing messages), 16486-P0102 (mass or volume air flow/low input) and 17988-P1580 (throttle actuator B1 malfunction). A full list of diagnostic trouble codes, or DTCs, can be found in the Volkswagen owner's manual or at www.bentlypublishers.com.
DTCs are assigned two-part numerical codes followed by a P-code. The first code is assigned by the factory. The P-code follows a structure defined by the Society of Automotive Engineers that is required by law.
A letter designates the system, and the four numbers that follow further detail the malfunction. The first digit structure is "Pxxxx" for powertrain, "Cxxxx" for chassis, "Bxxxx" for body and "Uxxxx" for future systems. The second digit structure is "P0xxx" for Government required codes and "P1xxx" for manufacturer codes for additional emission system function that are not required but reported to the government.
The third digit structure is: "Px1xx" for measurement of air and fuel, "Px2xx" for measurement of air and fuel, "Px3xx" representing the ignition system, "Px4xx" for additional emission control, "Px5xx" for speed and idle regulation and "Px6xx computer and output signals."
Furthermore, "Px7xx" signifies transmission, "Px8xx" is also for transmission and "Px9xx" represents control modules, input and output signals. The fourth and fifth digits classify the individual components and systems. Volkswagen DTCs can be retrieved with VW/Audi factory scan tools and diagnostic computers through a data link connector.