I am an ase certified repair tech. I replaced the front pads on a 97 c 230 Mercedes with Wagner thermo quiet pads. The sensors appeared to be good, jbut after the repairs the brake light comes on every time you hit the brakes. The brakes function properly and stop exceptionally well. I also replaced an o2 sensor which fixed the performance issue, but my scanner will not clear codes, even after it tells me codes were cleared successfully.
Try unhooking the front brake wear sensor to see if the light goes out, if it does replace worn sensor. Also check rear pads, they are equipped with wear sensors also, check the same way. You might just try another scanner or access the onboard system, with high mileage cars they can be kind of finicky when trying to reset codes. If all else fails remove neg cable from battery post, turn key to on position and let sit for 10 minutes, shut key off and reconnect neg. Cable. If it still has the code you will have to start the diag. Procedure as you still have a problem. Thank you for using 2CarPros