On Alientech KESSv2 - VAG 1.6 TDI Siemens PCR2.1 ECU - ECU Removal or OBD2 selection

At the end of the ID command launched by the Protocols 352 (VAG SIMOS PCR2.1 CAN) and 391 (VAG SIMOS 8.4 CAN) the "ECU status" is displayed:

• UNLOCKED -> You do not need to unlock - OBD2 Read and Write OK
• LOCKED -> You have to unlock - ECU Removal

So you can perform the correct procedure for programming the ECU.