Technical Bulletin (Update Programming of ECM for Concerns of a Bump Sensation after Coming to a Stop):
Current ECM programming may cause a bump after coming to a stop, which may be felt through the chassis of the vehicle. This concern is caused by the engine torque being slightly high when the transmission goes into Neutral Control. Neutral Control is designed to reduce load on the engine during idle, in order to decrease emissions.
The production solution to this issue was improved software for smoother stopping.