Not sure of your question.....on the Impala SS the small bulb behind the amber reflector comes on with parking/driving lights. One larger clear bulb in front of it lights up when your turn signal is activated.
There are only 2 bulbs on the corner of the Impala, you are having an issue with the bigger one of the 2. Pull it, get a number off it or take it to parts shop for cross reference and replace. See if it works.