This system consists of four main components: Diesel Exhaust Fluid Temperature Sensor (DEFTS), Diesel Exhaust Fluid Level Sensor (DEFLS), Diesel Exhaust Fluid Quality Sensor (DEFQS), and the mechanical interface points. The DEFTSA monitors the DEF level, temperature, and quality of the urea solution. The mechanical interface defines the requirements for connecting to the DEF tank, SCR system and vehicle interface.