CONSTRUCTION
The millimeter wave radar sensor assembly emits electrical waves in the millimeter waveband towards the front of the vehicle. When a preceding vehicle is present, the sensor receives electrical waves reflected off of the rear surface of the preceding vehicle. The system determines whether there is a preceding vehicle in the same lane and calculates the distance to the preceding vehicle and relative vehicle speed according to the change in frequency of the received electrical waves and using an electronic scan. This calculated data is then output to the driving support ECU assembly. For details about the millimeter wave radar sensor assembly, refer to PRE-CRASH SAFETY SYSTEM.