Two resistors are used to signal park/cont mode.
With ACC on, ID pin resistance to ground is 12.9 kohm.
ACC off its 30.9 kohm.
The dash cam has a pull up on the ID pin. When the parking mode timer is up the dash cam releases the ID pin, it drops to 0 v and the switch mode converter is shut off. It can't power on again until you turn the car key. Some speculation there.