The headlamp motor control module is not seeing a "stop/not turning" condition of the motors and is running until the timeout (~6 seconds). At least two things can cause that. One possibility is that the mechanical stops on both lamp motor actuators are missing/broken. You can verify that by operating each motor manually and seeing if the headlamp door stops when up, or continues to cycle down. The second possibility is a defective headlamp control module relay. That requires replacement of the module, since the relay is soldered in and is not a common type. A third, less likely, possibility is that the signal voltage to the module is too low. That signal comes from the headlamp switch and the power comes from the fuse block. If the headlamps are dim, that could be the reason.
