Retrieving the 4 or 5-digit Secret Key Code (SKC) required for programming new keys or matching replacement instrument clusters.
The "120" is not a professional-level tool (like an Abrites or ODIS), but it is the industry standard for locksmiths and independent garages performing low-to-medium volume VAG work.
Disclaimer: This article is for educational purposes. Modifying your vehicle's immobilizer or odometer may violate local regulations. Always consult a professional locksmith for critical repairs.
The immobilizer (Immo) is a common failure point. When the ECU loses sync with the cluster, the car cranks but does not start. Using the Programmer 120: