Enhanced diagnostic signal to detect pressure condition of a particulate filter
View Patent ↗An exhaust gas treatment system includes a particulate filter to collect particulate matter from exhaust gas flowing therethrough. The particulate filter realizes a pressure thereacross in response to the exhaust gas flow. A delta pressure sensor determines a first pressure upstream from the particulate filter and a second pressure downstream from the particulate filter. A delta pressure module is in electrical communication with the delta pressure sensor. The delta pressure module determines a pressure differential value based on a difference between the first pressure and the second pressure and generates a diagnostic signal based on a plurality of the pressure differential values and a predetermined time period.
1. An exhaust gas treatment system included with an internal combustion engine, comprising:
a particulate filter to collect particulate matter from exhaust gas flowing therethrough, the particulate filter realizing a pressure thereacross in response to the exhaust gas;
a delta pressure sensor to determine a first pressure upstream from the particulate filter and a second pressure downstream from the particulate filter;
a delta pressure module including an electronic microprocessor in electrical communication with the delta pressure sensor to determine a pressure differential value based on a difference between the first pressure and the second pressure and to generate a diagnostic signal based on a plurality of the pressure differential values and a predetermined time period; and
a debounce module including an electronic microprocessor in electrical communication with the delta pressure module to count a plurality of fail conditions over the predetermined time period, and to generate a fail signal indicating a pressure fail event in response to the plurality of the fail conditions exceeding a predetermined count threshold.
2. The exhaust gas treatment system of claim 1 , wherein the delta pressure sensor includes a front line coupled to a first port disposed upstream from the particulate filter to determine the first pressure and includes a rear line coupled to a second port disposed downstream from the particulate filter to determine the second pressure.
3. The exhaust gas treatment system of claim 2 , wherein the delta pressure module determines at least one fail condition of the particulate filter based on a comparison between the diagnostic signal and at least one threshold value.
4. The exhaust gas treatment system of claim 3 , wherein the at least one fail condition includes a low-pressure fail condition and a high-pressure fail condition.
5. The exhaust gas treatment system of claim 4 , wherein the delta pressure module determines the low-pressure fail condition in response to the diagnostic signal existing below a first predetermined threshold and determines the high-pressure fail condition in response to the diagnostic signal existing above a second predetermined threshold.
6. The exhaust gas treatment system of claim 5 , wherein the low-pressure fail condition indicates a damaged particulate filter, and the high-pressure condition indicates at least one of a blockage of the particulate filter and a miscommunication between the rear line of the delta pressure sensor and the downstream port.
7. The exhaust gas treatment system of claim 6 , further comprising an entry condition module in electrical communication with the delta pressure module to generate an entry condition signal in response to the occurrence of the at least one entry condition, wherein the delta pressure module generates the diagnostic signal in response to receiving the entry condition signal.