I would suggest that if you had perfect function before you replaced your tailight bulb then the bulb is possibly in backwards in the socket and not grounding through the base. Instead, they are grounding through the other bulbs. I am just guessing but several of my Benz cars have done the same thing.

The light on your dash senses that the current flow to your brake lights is incorrect, bulb burnt or loose.
Try resetting the bulb and be sure it is the right one. A wrong bulb with the same base may fit but won't have the right resistance and that will also turn on your warning light.

Again just guessing...


roadster with a stick