What is this noise from the driver front wheel area? (Electronic screeching)




I couldn't find anything on this so I took a quick video and am posting this to see if anyone can help me?
I checked STAR and zero issues/faults. Nothing is coming back as an error.
2009 W211 with AMG package. I don't have SBC brakes nor do I have air suspension.
Retro fits done over the last couple years (though I don't think any of this has any bearing on it): Bi-xenon (non active curve) headlights, e55 caliper/rotor upgrade, rear illuminated overhead console, power opening/closing trunk.
You can hear the noise in the below video:
Thanks much,
-Nigel




I'll update if something else happens.
Install was easy. Remove the rear front fender lining and it's right there. Undo two metal bolts, pull the bracket down and then disconnect the harness and one single bolt to the siren. Do the opposite for installation and you're done. Maybe a 30 minute install.
-Nigel


