Mercedes-Benz W203 C-Class ABS Sensor Replacement

The ABS wheel speed sensor on the Mercedes C320 monitors road wheel movement and sends an electronic signal to the ABS module. This signal is used to calculate road wheel speed to help with ABS braking and stability control features. When an ABS wheel speed sensor fails, the ABS module loses road wheel speed for the corresponding wheel and sets a fault code for ABS wheel speed signal. When a fault code is set, the ABS warning light will illuminate. You will have to scan the module and read the fault codes to determine which speed sensor is the problem. Keep in mind, other problems can illuminate the ABS warning light, be sure to scan and read fault codes before you start replacing expensive parts. In this article, I will go over how to replace the front and rear ABS wheel speed sensors on your Mercedes W203. Begin by jacking up and supporting the car, please see our article on jacking up your Mercedes. Remove the front and rear wheels. With the front wheels off you will see two cables running from the upper fender to the steering knuckle. One will go to the caliper; that is the brake wear sensor. The other cable is the ABS wheel speed sensor and attaches to the steering knuckle. Use a 10mm wrench and remove the bolt holding it to the knuckle. You will need to release the harness from the retaining clips as you go. The bolt securing the sensor is micro encapsulated, so if you are reusing it, you should clean it up and use a little blue Loctite when reinstalling it. Use a...