The software operates by processing "dump files" — raw data extracted from an ECU using external hardware programmers like UPA-USB or the Wellon series. IMMO Universal Decoding v3.2 Overview | PDF - Scribd

: When the ignition is engaged, the ECU verifies a unique security code from the key. If the code is missing or incorrect, the ECU disables critical functions like the fuel injection and ignition circuits, preventing the car from starting.

The standard immobilizer relies on three core components: a transponder chip in the key, an antenna coil near the ignition, and the ECU.