Mercedes C Klasse Bumper Antenna Issue

I had something similar on my C Klasse, but not the exact same symptoms. The keyless entry was acting up, and the radio reception was terrible. It turned out to be a corroded connection on the antenna amplifier, which was near the rear bumper. Think of it like a kinked garden hose, the signal can't flow. Check the connections and wiring around the antenna. It might just be a loose or damaged wire. Also, be sure there is no damage at the antenna mount. It might save you a trip to the shop.

Thank you for your response. Could you give me more specific information about where that antenna amplifier is located? Are there any tools or procedures you'd recommend for checking the connections and wiring? I'm reasonably handy, but I don't want to cause more damage. Is there any chance the fm antenna itself is broken?

I don't remember the exact location, but it was close to the bumper. I wouldn't go too deep without the right tools or diagrams. Given the symptoms, and that you could make things worse, I'd suggest a qualified technician. It sounds like the cable or plug connection of the component is defective as the initial diagnostic suggests. Paying 95€ is probably worth it to avoid bigger problems.

I appreciate the cautious advice. I took the car to a trusted shop. The issue was a faulty connection in the bumper antenna wiring, as suspected. The antenna repair was done for the estimated cost. Thanks again for your help.