A method and tail light for controlling optical modules of the tail light, comprising the steps of activating one or more optical modules to generate a first signaling function, if the vehicle has reverse gear engaged, activating, according to a first mode of operation, one or more other optical modules to generate a second signaling function, if the vehicle does not have reverse gear engaged, activating the or at least one of the other optical modules to generate a complementary beam of light distinct from the beam of light that it emits in the first mode of operation and that supplements the first signaling function. The invention also relates to a tail light, notably for implementing this method.