General Motors Corp
The vehicle could roll away after the driver has exited, NHTSA said in its notice.
Investigators also suspect the gear problem could have been behind warranty complaints that certain vehicles would not restart once placed in park.
The 2009 Models affected include the Chevrolet Cobalt, HHR, Malibu, Traverse and the GMC Acadia, Pontiac G5, G6 and the Saturn Aura and Outlook.
About three quarters of the vehicles identified in the recall remain in dealer lots or with the manufacturer, a GM spokeswoman said.
The company said it was not aware of any accidents or injuries related to the problem.
(Reporting by John Crawley; Editing by Andre Grenon and Gunna Dickson)