The rolling code between the key and the ECU gets out of sync, preventing the engine from firing.

If you are facing issues with your Opel immobilizer or transponder programming, Understanding the "Opel Crypto 33" System

The "Crypto 33" refers to the , a rolling code chip that communicates with the car’s Immobilizer 1 (Immo1) system. Unlike modern "plug-and-play" systems, these older chips require specific EEPROM data from the immobilizer box to be written onto a blank transponder so the car will start. Common Problems (Why You Need a "Fix")

Use the "Programming" menu within OP-COM to "Erase Transponder Keys" and then "Program Transponder Key."

Many older "fixed-code" or "crypto" software tools do not run correctly on modern Windows 10 or 11 operating systems. How to Fix Opel Crypto 33 Issues 1. Software Compatibility Fix