Will it cause any damage to the engine/transmission if one switches from N to D without pressing the brake pedal?
I was driving at about 40 mph when I accidentally switched to N. Then after a while I switched again to D, but I didn't press the brake pedal. The auto is Hyundai Accent 2016. The manual says that one should always press the brake before switching from N to D, but is it so bad if I did not press only once?
Should be no problem at all.
The manual is being overly cautious, since the usual case for shifting from neutral into drive is when you're stopped hold the brake will prevent the car from starting to move until you release the brake. But when you're already moving there is no need to hold the brake.
On contemporary vehicles there is no direct mechanical linkage between the gear selector and the automatic transmission.
Instead, the gear selector selects a "state" (e.g. N, D, R, 1, 2...) which is relayed electronically to the transmission controller and acted upon if the circumstances are deemed favorable.
