What is the reason for the reverse light not turning on when shifting to reverse gear?

[Lois]

The gear position and reverse light are connected by sensors and several wiring harnesses. When the transmission is shifted into reverse gear, the sensor will transmit the command to the reverse light in the tail light according to the instruction (whether it is LED or ordinary, there will be contact). At this time, the reverse light will turn on. Here is some extended information: Car light sensor: In general automatic transmission vehicles, the D gear is connected to the sensor for locking the car. As long as the vehicle is shifted to D gear, the vehicle will automatically lock (of course, the premise is that the ignition is on, because without ignition, it is impossible to shift to D gear). In contrast, Volkswagen vehicles usually automatically lock when the speed exceeds 20 km/h. The P gear is connected to the vehicle's unlocking sensor. As long as the vehicle is shifted to P gear, it will automatically unlock.