Musk said the "attachment strength of the mounting bracket for the left hand latch of the second row seat could be weaker than intended. This reduces our confidence that the left hand seat back will be properly retained in the event of a crash." The recall includes Model S vehicles manufactured between May 10, and June 8, 2013.
According to the blog post, the Model S backseat attachment is both bonded and welded, but the company discovered that after body side alignment adjustments had been made, the bond was "compromised" and the welding was "weakened in some cars."
Musk went on to say that the weld has not detached on any car, there have been no customer complaints, and Tesla is not aware of any injuries or "near injuries" as a result. Tesla discovered the problem on its own and said no regulatory agency had brought the issue to its attention. A post on a National Highway Traffic Safety Administration site says 1,228 vehicles are affected.
Tesla said it's contacting affected Model S owners in the next few days to arrange for the cars to be picked up. Tesla will reinforce the bracket and then return the cars to their owners. The company made a specific note that customers don't need to take their cars to a Tesla service center.
"Tesla will pick up the car at a location of the owner's convenience, provide a Model S loaner if needed, perform the work and bring the car back to the owner a few hours later," Musk wrote, signing the blog post "Apologies for the inconvenience."