As you will note my car is a 2015. I have had two interactions with the dealer related to Blind Spot Assist Inoperative. At the first instance, about a year and a half ago. they had to remove the rear bumper and install new 'Cans', because they said the old ones were corroded. Whatever they did solved the problem until this past winter. It seems that I got the message when it was very cold out. I reported it at my February B service and they investigated. This was their report: "Connected battery charger and performed quick test. Found codes for sensor 8 not configured and message missing. Performed visual inspection of sensors and harness. Did not find any corrosion or defects. Followed guided test and performed control unit initialization and coding. Cleared codes and performed second quick test. Performed test drive. No codes returned and all is functioning properly at this time." In fact, the system has been functioning normally since then. It also got warmer.
2015 GLA250 Polar Silver Black MB Tex FWD
H19 Poplar Trim 234 Blind Spot Assist
413 Panorama Sunroof 508 Becker Map Pilot
889 Keyless Go 00A Illuminated Star
068 Wheel locking bolts P01 Premium Package (Sirius, Media Interface, Heated front seats, HK Logic 7, Garage, Compass, Auto dim, 2 zone Climate