The National Highway Traffic Safety Association (NHTSA) said it has opened an investigation into Mercedes-Benz USA's compliance with federal laws and execution lapses over 1.4 million safety recalls in the past 18 months.
A review showed that the company may have missed deadlines in notifying letters to the owners as well as timely submission of representative copies of communications to NHTSA, the auto safety agency said in a letter dated Oct. 22.
In addition, the recall reports omitted important details such as estimated percentage of defected units affected by the recall and its recall plans, the agency said.
"Even when notified of the omissions, the company was at times slow to provide the missing information," NHTSA said on its website.
Daimler, which owns Mercedes-Benz, did not immediately respond to a request for comment on the matter.