Abstract: A control system for a vehicle is provided. The control system includes a signal processing module that receives a sensor signal and extracts a plurality of sample points from the sensor signal. A computation module computes a summation of the sample points, computes a summation of squares of the sample points, and computes a standard deviation based on the summation of the sample points and the summation of the squares of the sample points. A control module generates a control signal based on the sensor signal and the standard deviation.

Abstract: A diesel oxidation catalyst (DOC) testing system includes a DOC that is located in an exhaust system of a vehicle. A control module verifies proper operation of the DOC during a post-fuel injection process in an engine of the vehicle. The control module computes a predicted temperature of exhaust gases at an output of the DOC that corresponds with proper operation of the DOC during the post-fuel injection process, determines an actual temperature of the exhaust gases during the post-fuel injection process, and activates an alarm indicator when a difference between the predicted temperature and the actual temperature is greater than a first predetermined value. A first temperature sensor is located downstream from the DOC in the exhaust system. The first temperature sensor communicates with the control module, generates the actual temperature, and transmits the actual temperature to the control module.

Abstract: A control module for an engine of a vehicle includes a mode determination module that determines whether the vehicle is in a fuel-saving mode based on an acceleration of the vehicle. A diurnal control valve (DCV) control module selectively closes a DCV a predetermined time after at least one of determining that the vehicle is in the fuel-saving mode and determining that the engine is stopped.

Abstract: A vehicle includes a sealed fuel system and a controller. The fuel system includes a fuel tank, a fuel cap, a control orifice, and an absolute pressure sensor. The controller associates a threshold large leak in the fuel system with a fuel cap sealing error. The controller detects completion of a prior refueling event, compares measurements from the pressure sensor to a reference vacuum across the control orifice to determine the presence of the threshold large leak, and sets a diagnostic code corresponding to the large leak only upon completion of the prior refueling event. A method for detecting the large leak includes detecting completion of the refueling event, comparing vacuum measurements from the absolute pressure sensor to a reference vacuum across the orifice to determine the presence of the large leak, and setting a diagnostic code corresponding to the large leak only upon completion of the prior refueling event.

Abstract: A method of monitoring an onboard diagnostic system for a plug-in hybrid electric vehicle includes incrementing the denominator of an N/D ratio for the onboard diagnostic system only when a total time criteria, a vehicle speed criteria and an idle criteria are satisfied after an internal combustion engine of the vehicle has been fueled. The diagnostic system performance is summarized into a single N/D ratio. When an underperforming ratio is identified, the system controls the engine to provide more engine operation and subsequent diagnostic observability. The denominator of the N/D ratio is compared to a verification denominator to identify vehicles that are typically operated in a manner such that an engine-on cycle does not begin, or is not identified, until very near the end of the drive cycle, thereby preventing the denominator and a numerator of the N/D ratio from incrementing, and thereby providing a false passing performance ratio.

Abstract: A method of assessing overall efficiency of a selective-catalytic-reduction catalyst includes monitoring instantaneous efficiency of the catalyst. The method also includes determining the overall efficiency by summing instantaneous efficiency values weighted by a first set of coefficients if the most recent instantaneous efficiency value is above an instantaneous efficiency threshold. The method additionally includes determining the overall efficiency by summing instantaneous efficiency values weighted by a second set of coefficients if the most recent instantaneous efficiency value is equal to or below the instantaneous efficiency threshold. Furthermore, the method includes determining whether the overall efficiency has dropped below an overall efficiency threshold and reporting when the overall efficiency has dropped below the overall efficiency threshold.

Abstract: A method of detecting an in-range failure of a brake pedal position sensor includes calculating the difference between a minimum position and a maximum position of the brake pedal position sensor. The calculated difference is weighted to define a fast test weighted input value and/or a full test weighted input value. A cumulative test result value is incremented by the fast test weighted input value and/or the full test weighted input value. The cumulative test result value is filtered to define a moving average of the cumulative test result value after each incremented occurrence. The moving average of the cumulative test result value is tracked to determine if the brake pedal position sensor is functioning properly.

Abstract: A vehicle includes a sealed fuel system and a controller. The fuel system includes a fuel tank, a fuel cap, a control orifice, and an absolute pressure sensor. The controller associates a threshold large leak in the fuel system with a fuel cap sealing error. The controller detects completion of a prior refueling event, compares measurements from the pressure sensor to a reference vacuum across the control orifice to determine the presence of the threshold large leak, and sets a diagnostic code corresponding to the large leak only upon completion of the prior refueling event. A method for detecting the large leak includes detecting completion of the refueling event, comparing vacuum measurements from the absolute pressure sensor to a reference vacuum across the orifice to determine the presence of the large leak, and setting a diagnostic code corresponding to the large leak only upon completion of the prior refueling event.

Abstract: A method of monitoring an onboard diagnostic system for a plug-in hybrid electric vehicle includes incrementing the denominator of an N/D ratio for the onboard diagnostic system only when a total time criteria, a vehicle speed criteria and an idle criteria are satisfied after an internal combustion engine of the vehicle has been fueled. The diagnostic system performance is summarized into a single N/D ratio. When an underperforming ratio is identified, the system controls the engine to provide more engine operation and subsequent diagnostic observability. The denominator of the N/D ratio is compared to a verification denominator to identify vehicles that are typically operated in a manner such that an engine-on cycle does not begin, or is not identified, until very near the end of the drive cycle, thereby preventing the denominator and a numerator of the N/D ratio from incrementing, and thereby providing a false passing performance ratio.

Abstract: An outside air temperature (OAT) diagnostic system includes an ambient temperature monitoring module that receives (i) an OAT signal from an OAT sensor and (ii) an intake air temperature (IAT) signal from an IAT sensor of an engine. The ambient temperature monitoring module compares the OAT signal to an IAT signal and generates a first difference signal. A performance reporting module determines whether the OAT sensor is exhibiting a fault and generates an OAT performance signal based on the first difference signal.

Abstract: A diagnostic system for a vehicle includes a first sensor that generates a first status signal, which is indicative of an engine speed of an engine. A second sensor generates a second status signal that is indicative of an actual accessory speed of an accessory. The accessory is coupled to the engine via a belt system. A control module determines an expected accessory speed based on the engine speed and determines a residual accessory speed based on the expected and actual accessory speeds. The control module also detects a fault in the belt system based on the residual accessory speed.

Abstract: 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.

Abstract: A control system for evaluating an engine oil temperature sensor is provided. The control system includes a first diagnostic module that selectively detects a first engine oil temperature sensor fault based on a comparison of engine coolant temperature, intake air temperature, and engine oil temperature. A reporting module selectively generates a fault report based on the first engine oil temperature sensor fault.

Abstract: A control system and method for controlling pump includes a pump control module communicating a drive signal to the high pressure pump and a high pressure pump in communication with the pump control module operating in response to the drive signal. A current sampling module samples a pump current signal to form a sample prior to an end of the drive signal. A current comparison module compares the sample to a threshold that may be a function of pump solenoid resistance, pump solenoid temperature, and/or system voltage, and a fault indication module generates a fault signal in response to comparing.

Abstract: An engine control system includes a driver module and a diagnostics module. The driver module includes a high-side driver and a low-side driver, which selectively actuate a load. The driver module generates status signals based on detection of each of a plurality of failure modes of the high-side and low-side drivers. The diagnostics module increments a first error count for a first mode of the plurality of failure modes when the status signals indicate the driver module has detected the first mode. The diagnostics module increments a corresponding total count each time the driver module analyzes the first mode. The diagnostics module sets a fail state for a diagnostic trouble code (DTC) when the first error count for the first mode reaches a first predetermined threshold prior to the total count reaching a second predetermined threshold.

Abstract: An engine control system includes a driver module and a diagnostics module. The driver module includes a high-side driver and a low-side driver, which selectively actuate a load. The driver module generates status signals based on detection of each of a plurality of failure modes of the high-side and low-side drivers. The diagnostics module increments a first error count for a first mode of the plurality of failure modes when the status signals indicate the driver module has detected the first mode. The diagnostics module increments a corresponding total count each time the driver module analyzes the first mode. The diagnostics module sets a fail state for a diagnostic trouble code (DTC) when the first error count for the first mode reaches a first predetermined threshold prior to the total count reaching a second predetermined threshold.

Abstract: A method and control module for determining a sensor error includes a time-based diagnostic module generating a time-based diagnostic for a sensor and an event-based diagnostic module generating an event-based diagnostic for the sensor. A synchronizing module synchronizes the time-based diagnostic and the event-based diagnostic to obtain a diagnostic result. A fault indicator module generates a fault signal in response to the diagnostic result.

Abstract: A control system and method for controlling pump includes a pump control module communicating a drive signal to the high pressure pump and a high pressure pump in communication with the pump control module operating in response to the drive signal. A current sampling module samples a pump current signal to form a sample prior to an end of the drive signal. A current comparison module compares the sample to a threshold that may be a function of pump solenoid resistance, pump solenoid temperature, and/or system voltage, and a fault indication module generates a fault signal in response to comparing.

Abstract: A diagnostic system and method for detecting failures in a fuel system of a vehicle includes a fuel level monitoring module that determines a first change in a first fuel level of a first fuel tank based on data received from a first fuel level sensor and determines a second change in a second fuel level of a second fuel tank based on data received from a second fuel level sensor. A sensor diagnosing module evaluates operation of the second fuel level sensor based on the first change in the first fuel level.

Abstract: A control system for an engine includes an air calculation module that determines, based on a plurality of first coolant temperatures sensed during a period of engine operation, a first cumulative mass of intake air combusted by the engine during the period that corresponds to an estimated amount of heat dissipated by a cooling system of the engine during the period, and that determines, based on the first cumulative mass, a second cumulative mass of intake air of the engine that is required to raise a temperature of the engine from an initial temperature at a start of the period to a target temperature. The control system further includes a control module that selectively adjusts one of a diagnostic condition and an operating condition of the engine based on the second cumulative mass. A related method for controlling an engine is also provided.