The sensors are connected to the center console via a wiring harness. If you damage or fail to connect all of your sensors, you'll get a fault warning. Either make the bumper you have that is incorrect work, or save your money and get the right bumper. Or look for the right bumper as a used part. ALL 1997/1998/1999 CL's had the sensors, it was not an option like on the sedan, so you have the wrong bumper on the car to begin with.