i40 Radio Antenna Error

That sounds frustrating! I have an i40 as well, and I experienced something similar a while back. The error messages were constant, and the FM signal would drop out, especially in areas where it should have been strong. Did you check the antenna base for any corrosion or damage? In my case, the poor reception was due to water ingress into the antenna base. You may want to check whether the antenna cable is properly connected to the receiver unit behind the head unit.

I'll check the antenna base for corrosion. Where exactly is the receiver unit located? And if it's water ingress, is there a way to fix it or is it just replacing the whole thing?

The receiver unit is generally integrated into the infotainment system behind the dash. Accessing it might require removing parts of the dashboard, which can be a bit tricky if you're not familiar with car electronics. As for the water ingress, it depends on the extent of the damage. Sometimes, cleaning and drying the contacts can help, but if corrosion is significant, replacement will be necessary. I highly recommend taking it to a trusted workshop; they are way more experienced and equipped to diagnose it properly and ensure no further damage occurs during disassembly and repair.

Thanks for the advice! Sounds like I'm better off letting professionals handle it. I'm going to take it to the shop tomorrow. They quoted me around 255€, which seems reasonable. At least I know what to expect. Fingers crossed it's just a simple antenna replacement!