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Mine also goes easily into 'D' after manually shifting (without holding it there). Also, FYI, the transmission WILL continue to upshift and downshift as you drive (while in manual mode) when it exceeds its programmed limits as a designed built-in safety. I do not remember where I read that, but it is in either the service manual or the owner's manual. This design proposes some might forget to put it back into 'D' mode, it is designed to 'protect itself'.
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