Immobilizer control module, replacing procedure

WARNING: This page does not describe the selected car, but rather 27 other vehicles, including the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, 2000 Volkswagen Cabrio, 1999 Volkswagen Jetta, and 1999 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

To avoid mix-up and false entry, determine 14-digit identification number for control module for immobilizer only by checking control module version using the VAG1551 Scan Tool (ST). Then use identification number to ask the appropriate distributor or importer for the 4-digit secret number required for adaptation!
Every control module for immobilizer has its own secret number!

Once the secret number is known, keys must be adapted first. See IGNITION KEYS, MATCHING (ADAPTATION) .
After adapting all keys, adapt Engine Control Module (ECM). See ENGINE CONTROL MODULE (ECM), PROCEDURE AFTER REPLACING .