Patent ID: 8205436

Claim:
An engine monitoring system to determine an unintended exothermic condition occurring in after-treatment (AT) components including a diesel particulate filter (DPF) of the engine exhaust system, wherein the AT components comprise a first AT component for treating exhaust gas, comprising: a first temperature sensor upstream of the first AT component and arranged to sense exhaust gas temperature and issue a corresponding first temperature signal; a second temperature sensor downstream of the first AT component and arranged to sense exhaust gas temperature and issue a corresponding second temperature signal ; a controller configured with a first function that monitors the first and second temperature signals and calculates a rate of change of temperature of exhaust gas at each sensor, and a second function that compares both the first and second temperature signals and the rate of change of temperature to predetermined thresholds for determining whether an unintended exothermic condition exists within the first AT component, and a third function that issues a fault signal; a second AT component in series with the first AT component; the second temperature sensor being between the first and second AT components; a third temperature sensor downstream of the second AT component and arranged to sense exhaust gas temperature and issue a corresponding third temperature signal; the first function monitors the third temperature signal and calculates a rate of change of temperature of exhaust gas at the third temperature sensor, and the second function compares the temperature and rate of change of temperature at the second and third temperature sensors to predetermined thresholds for determining whether an unintended exothermic condition exists within the second AT component, and the third function issues a fault signal.