The invention relates to a computer-implemented method for protecting at least one on-board plug-in module (1a, 1b, 1c, 1d, 1e, 1f) from theft, wherein the non-radio module (1a-1f) functions in a wired manner when it is plugged into a connector socket (2a, 2b, 2c) of a vehicle (3).The procedure comprises the following steps: a) Detection (S1, S1') of the module (1a-1f) by a vehicle computer (3b) of the vehicle (3) when the module (1a-1f) is inserted into the connector (2a-2c), b)
Authentication (S2, S2') of the module (1a-1f) by the vehicle computer (3b) and establishment of a
data connection to the module, c) Sending (S3, S3') by the vehicle computer (3b) a unique module identifier (1a', 1b', 1c') assigned to the module (1a-1f) and a
unique user identifier (4a') assigned to a user (4) of the module (1a-1f) to a
server (7) connected to the vehicle computer (3b), d) Requesting (S3) by the vehicle computer a
pairing status of the unique module identifier (1a'-1c') and the
unique user identifier (4a') from the
server (7) which has a module mapping
list (8) with at least one entry (8c', 8c'', 8c''', 8c. IV) includes, which assigns a listed unique module identifier (1a'-1c') to a listed
unique user identifier (4a') that is paired with the listed unique module identifier (1a'-1c'), and e) if the
pairing status is determined by the
server (7) to be unpaired (S3b), so that the unique module identifier (1a'-1c') and the unique
user identifier (4b) sent to the server (7) in step c) are not listed as paired, blocking (S5) the use by the vehicle computer (3b) of the module (1a-1f) plugged into the vehicle's connector (2a-2c) of the vehicle (3). Other aspects of the invention are a
computer program product that causes a computer to execute the method, and a
system for protecting the at least one on-board plug-in module (1a, 1b, 1c, 1e, 1f) from theft.