the dude

on the code list on dtr what does rationality mean after the code??????

kwilkinson

The controllers throughout the truck interact with each other and all the sensors, and when there is one sensor that is not reading what it should compared to what another sensor is reading, then the controller finds it "irrational". Some rationality codes, like coolant temp rationality, is where the reading does not change or does not change enough in a given time period. Controllers have set parameters for each sensor, and it compares the inputs from each sensor to calculate a proper output. When one sensor seems to not be right, the controller throws a rationality code and defaults to a set value for that sensor until the sensor is fixed and code is cleared. Hope thats understandible