For service truck maintenance workers, good news on the DEF (diesel exhaust fluid) sensor shortage afflicting the trucking industry—a solution has been found.
Owing to a recent shortage of DEF sensor replacements, thousands of trucks have been sidelined, as the sensor failure causes the trucks to shut down and stranded.
While the shortage of actual replacement DEF sensors continues—some carriers have reported delays going back to June—and some carriers have provided temporary fixes of their own, a new software override solution has been developed to better alleviate the situation.
The new software coding fix will circumnavigate the DEF sensor failure readings to allow the engine to operate normally—if the DEF tanks remain full, placing the onus on the driver and fleet operators.
A DEF unit is used in a truck’s selective catalytic reduction system to reduce GHG gas emissions from engine exhaust gas. It integrates liquid level and temperature measurement functions, as well as a heating function utilizing the engine’s coolant. DEF sensors are used to ensure the correct levels of diesel exhaust fluids are being used by the truck’s engine to provide optimal efficiency.
The software patch still needs to receive approval from the US Environmental Protection Agency (EPA) to ensure that the computer coding does not cause a running truck to operate with a defective sensor that could affect it negatively or that its effects do not violate any federal emission laws.
Work on developing a solution for the sensor shortage and development of the software coding progressed with the aid of the Truck and Engine Manufacturers Association, the EPA, and the California Air Resources Board, and many truck companies, such as Cummins Inc. and Navistar.
The shortage of new DEF sensor parts looks to continue for the near future, clearly affected by supply chain issues stemming from shutdowns and labor shortages caused by Covid-19 pandemic.