Two technicians are describing DEF (diesel exhaust fluid) operation. Technician A says that the amount of DEF used is in proportion to the amount of exhaust NOx. Technician B says that some DEF systems base the dosage on a probability of NOx in the exhaust system by using algorithms stored in the ECM. Who is right?

Question

Quizplus · Accepted Answer

Technician A is correct because DEF usage is proportional to the amount of NOx in the exhaust. Technician B is also correct because some systems use algorithms to estimate NOx levels and adjust DEF dosing accordingly.

Two Technicians Are Describing DEF (Diesel Exhaust Fluid) Operation