Exhaust Treatment System with Urea Temperature Rationality Diagnostic

摘要

A method for monitoring an exhaust after-treatment system that doses an exhaust treatment fluid held from a tank into an exhaust stream. The method includes determining a first temperature of the exhaust treatment fluid in the tank using a temperature sensor. If the first temperature of the exhaust treatment fluid is less than a predetermined temperature, a heater is activated to increase the first temperature of the exhaust treatment fluid. The increasing first temperature is then monitored relative to the predetermined temperature. Then, a second temperature when a phase change of the exhaust treatment fluid occurs is detected. The detected second temperature is then compared to the predetermined temperature to determine whether the exhaust treatment fluid is of sufficient quality, or to determine whether the temperature sensor is rational.

主权项

1. A method for monitoring an exhaust after-treatment system that doses an exhaust treatment fluid held from a tank into an exhaust stream, the method comprising:
determining a first temperature of the exhaust treatment fluid in the tank using a temperature sensor; if the first temperature of the exhaust treatment fluid is less than a predetermined temperature, activating a heater to increase the first temperature of the exhaust treatment fluid; monitoring the increasing first temperature of exhaust treatment fluid relative to the predetermined temperature; detecting a second temperature when a phase change of the exhaust treatment fluid occurs; and comparing the detected second temperature to the predetermined temperature.