This sensor is a smart combo sensor; it does three things, tank level, tank temperature, and DEF quality. By smart I mean it is data-linked to the ECM's that control engine. In this third Dr Paccar truck repair video I discuss the issue of failed 2016 to 2019 Kenworth DEF Quality sensors. Although I focus on Paccar power this als... In this third Dr. The C-2's DEF quality sensor is in the head of the tank. dsalinas1939. Top Member. USA. 1186 Posts. Posted - 11/05/2018 : 07:27:27 AM. yeah i thought the hole head would have to be replaced but i cleared code last week and put bus on a route i came back this morning with a different code 3582 i been doin some research and have been reading that. Search: Cummins Def Quality Sensor. The Diesel Exhaust Fluid Market is expected to be around US$ 27 No Block Plates Required - Full Wireless Get a Cummins isx egr delete or a dpf delete.