Type in the part number into the internet and look for a exploded view of the pedal area. The switch should make contact the the brake pedal arm so dig around a bit.

ESP , BAS , ABS are all interrelated and share electronics, ( Stability program , Brake assist , Antilock brakes ) You will need a scan tool that reads the ABS system to go farther. Once you get a list of codes, clear the computer then drive again until a light comes on they scan and see what you have.

You are in the proper place to post.