| Patent application number | Description | Published |
|---|
| 20080302087 | Exhaust system monitoring methods and systems - A diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor is provided. The system generally includes a fuel control module that commands fuel to transition from a rich condition to a lean condition and that commands fuel to transition from the lean condition to the rich condition. A first diagnostic module monitors the post-catalyst oxygen sensor during the transition from the rich condition to the lean condition. A second diagnostic module monitors the catalyst during the transition from the lean condition to the rich condition. | 12-11-2008 |
| 20090048766 | AIR FUEL RATIO CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES - A fuel control system of an engine system comprises a pre-catalyst exhaust gas oxygen (EGO) sensor and a control module. The pre-catalyst EGO sensor determines a pre-catalyst EGO signal based on an oxygen concentration of an exhaust gas. The control module determines at least one fuel command and determines at least one expected oxygen concentration of the exhaust gas. The control module determines a final fuel command for the engine system based on the pre-catalyst EGO signal, the fuel command, and the expected oxygen concentration. | 02-19-2009 |
| 20090118988 | TORQUE CONVERTER CLUTCH CONTROL SYSTEM AND POST OXYGEN SENSOR PERFORMANCE DIAGNOSTIC SYSTEM - A system comprises a post oxygen performance diagnostic (POPD) module that performs a POPD of a post oxygen sensor, wherein the POPD includes a deceleration fuel cutoff (DFCO) portion. A torque converter control module adjusts operation of a torque converter clutch (TCC). The POPD module and the torque converter control module operate the TCC to control engine speed above a predetermined engine speed during the DFCO portion of the POPD. A method comprises performing a POPD of a post oxygen sensor, wherein the POPD includes a deceleration fuel cutoff (DFCO) portion and adjusting operation of a torque converter clutch (TCC) to control engine speed above a predetermined engine speed during the DFCO portion of the POPD. | 05-07-2009 |
| 20090198457 | ALGORITHM TO DIAGNOSE LEAKS OR BLOCKAGES DOWNSTREAM OF THE SECONDARY AIR INJECTION REACTION (SAIR) PRESSURE SENSOR - A control module and method for an exhaust system of an engine can include a secondary air intake (SAI) pressure module that monitors SAI pressure. An accumulation module can accumulate an SAI string length based on the monitored SAI pressure. A calculation module can determine an average SAI string length based on the accumulated SAI string length. A determination module can determine an operating characteristic of the vehicle exhaust based on the average SAI string length. | 08-06-2009 |
| 20100058848 | ENGINE COOLANT TEMPERATURE ESTIMATION SYSTEM - An engine coolant temperature estimation system comprises a coolant temperature estimation module and a coolant monitoring module. The coolant estimation module estimates an engine coolant temperature based on at least one of a mass air flow, a vehicle speed, and an ambient temperature. The coolant monitoring module selectively operates an engine based on the estimated engine coolant temperature. | 03-11-2010 |
| 20100077728 | AIR-FUEL IMBALANCE DETECTION BASED ON ZERO-PHASE FILTERING - A control system comprising an oxygen sensor that generates an oxygen signal based on an oxygen concentration level in an exhaust gas of an engine, a filtering module that determines a filtered signal based on the oxygen signal, and an air-fuel imbalance detection module that detects an air-fuel imbalance in the engine based on the oxygen signal and the filtered signal. A method comprising generating an oxygen signal based on an oxygen concentration level in an exhaust gas of an engine, determining a filtered signal based on the oxygen signal, and detecting an air-fuel imbalance in the engine based on the oxygen signal and the filtered signal. | 04-01-2010 |
| 20100114453 | SYSTEM AND METHOD FOR DETERMINING OXYGEN SENSOR HEATER RESISTANCE - An engine control module includes an exhaust heating module, a temperature determination module, and a resistance measuring module. The exhaust heating module operates an engine at a predetermined speed to generate an exhaust gas having a predetermined temperature. The exhaust gas heats a heating element of an oxygen sensor. The temperature determination module determines, based on the predetermined speed, when the heating element is heated to the predetermined temperature. The resistance measuring module determines a resistance of the heating element when the heating element is heated to the predetermined temperature. | 05-06-2010 |
| 20100138134 | ENGINE COOLING SYSTEM DIAGNOSTIC FOR APPLICATIONS WITH TWO COOLANT SENSORS - A temperature comparison module generates a temperature difference between an engine coolant temperature and a radiator coolant temperature. An energy determination module determines an energy value corresponding to heat energy generated by an engine. The heat energy increases at least one of the engine coolant temperature and the radiator coolant temperature. A diagnostic module generates a comparison of the temperature difference and the energy value and determines a status of a thermostat associated with the engine based on the comparison. | 06-03-2010 |
| 20100242933 | POST OXYGEN SENSOR PERFORMANCE DIAGNOSTIC WITH MINIMUM AIR FLOW - An engine control system includes an oxygen (O | 09-30-2010 |
| 20110106411 | SYSTEMS AND METHODS FOR DIAGNOSING OXYGEN SENSORS AND CATALYTIC CONVERTERS OF EXHAUST SYSTEMS - A diagnostic system for an engine includes a stage transition module and a control module. The stage transition module generates a command signal based on a fuel control signal. The command signal commands a fuel system of the engine to intrusively transition between rich and lean states during a diagnostic test that includes first, second, and third stages. The first, second, and third stages are defined based on transitions between the rich and lean states. The control module during the second and third stages detects: an error with a first oxygen sensor based on a comparison between the command signal and a first oxygen signal from the first oxygen sensor; an error with a second oxygen sensor based on a second oxygen signal from the second oxygen sensor; and an error with a catalytic converter based on the first and second oxygen signals and a manifold absolute pressure signal. | 05-05-2011 |
| 20110120095 | SYSTEM AND METHOD FOR MONITORING CATALYST EFFICIENCY AND POST-CATALYST OXYGEN SENSOR PERFORMANCE - A diagnostic system for an exhaust system of an engine includes a fuel control module and a diagnostic module. The fuel control module, in response to a request for a fuel inhibiting event, operates the engine in a first rich condition for a first period until a catalytic converter of the exhaust system is in a predetermined first rich state and subsequently operates the engine in a lean condition for a second period contiguous with the first period. The diagnostic module determines a catalyst efficiency of the catalytic converter based on an output of an oxygen sensor located downstream of said catalytic converter during the second period, and selectively adjusts a diagnostic status of the catalytic converter based on a comparison of the catalyst efficiency and a predetermined catalyst efficiency. The fuel inhibiting event may be a deceleration fuel-cutoff event. A related diagnostic method is also provided. | 05-26-2011 |
