A locking mechanism of a door leaf of a motor vehicle includes a latch, an electric actuator, and a transmission arrangement. The latch includes a pawl and a bolt configured to cooperate in such a manner to allow the locking or unlocking of the door leaf. The transmission arrangement is configured to transmit a movement of the electric actuator to the bolt in order to displace the bolt of the latch between an unlocking position in which the bolt is released from the pawl and a locking position in which the bolt is blocked by the pawl. The transmission arrangement includes a downstream transmission member configured to transmit a movement to the bolt, an upstream transmission member configured to transmit a movement of the actuator to the downstream transmission member; and a blocking member movable relative to the downstream transmission member and/or the upstream transmission member.