Diesel Exhaust Fluid (DEF) Sensor Shortage Updates

October 14, 2021

EPA is aware of how the global shortage of Diesel Exhaust Fluid (DEF) sensors is impacting vehicle owners, and we are working diligently with manufacturers to support them in providing solutions.

EPA has approved all the software solutions provided to us by the engine manufacturers, and manufacturers have already begun implementing many of them. Each manufacturer has numerous engine families, and each family typically requires a unique software solution. Manufacturers are determining the pace and sequence in which they complete software deployment for each of their engine families. Vehicle owners should contact their local dealership’s service department for information about when a solution for their specific vehicle will be available.

Background

The global microchip shortage, exacerbated by the COVID pandemic supply chain disruptions, has resulted in a shortage of Diesel Exhaust Fluid (DEF) sensors. These sensors are required on heavy-duty diesel vehicles to ensure that the emissions controls needed to meet clean air standards are in place and working. Typically, if a DEF sensor fails, it is easy to simply install another one. The shortage of these sensors, however, has created a problem for many vehicle owners who cannot get a replacement.