F10 BMW CAS4 (CAR ACCESS SYSTEM 4) IMMOBILIZER / THEFT-LOCKING CONTROL MODULE

** NOTE: a replacement used module must be put on a specialized locksmith/programming bench tool (such as Hexprog, VVDI Auto, or Autohex). The internal EEPROM data must be read from the original damaged unit and custom-flashed into the replacement unit to sync the secret security keys, matching VIN, and mileage thresholds. Failure to do so will throw immediate rolling code authentication errors, lock the ignition, and display anti-theft warnings.