This invention relates to the cylinder lock with a coded key for blocking the steering wheel shaft and the protection of motor vehicle from theft. The lock consists of the housing (1), which is fastened on the bush (2) placed on the shaft (3) of the steering system, inside of which there is a sliding cylinder (4) with a coded key (5). In the cylinder (4) there is a keyway (14) in which there is peak of the pin (13) fastened in the housing (1). On the core (8) by the linchpin (16) a bush (15) is fastened, on which there is a ring eccentre (17) with the area (18). On the bush (15) there is placed a spiral spring (20). In the housing (1) along the eccentre (17) the pin (19) and the inductive switch (27) are placed. Inside the bush (15) the spiral spring (24) and the piston (25) are placed, while the peak of the piston (25) is fastened by the linchpin inside the piston (26) for locking. The free end of the piston (26) is placed in the keyway (28) of the bush (29) fastened in the shaft (3). In order to unlock, the core (8) is rotated and the cylinder (4) is axially moved. In the unlocked position the ring eccentre (17) is secured by pin (19) and activates switch (27).