Abstract: A system includes a diagnostic module that selectively performs a purge valve leak diagnostic to diagnose a leak in a purge valve in a fuel system of a vehicle. Performing the purge valve leak diagnostic includes determining a level of vacuum in a fuel tank. A control module determines at least one operating condition associated with the vehicle. The at least one operating condition corresponds to an operating condition that affects the level of vacuum in the fuel tank. The control module, based on the at least one operating condition, selectively modifies the purge valve leak diagnostic. Selectively modifying the purge valve leak diagnostic includes at least one of preventing the diagnostic module from performing the purge valve leak diagnostic, preventing the diagnostic module from completing the purge valve leak diagnostic, and causing the diagnostic module to indicate that a result of the purge valve leak diagnostic was indeterminate.

Abstract: A system includes a diagnostic module that selectively performs a purge valve leak diagnostic to diagnose a leak in a purge valve in a fuel system of a vehicle. Performing the purge valve leak diagnostic includes determining a level of vacuum in a fuel tank. A control module determines at least one operating condition associated with the vehicle. The at least one operating condition corresponds to an operating condition that affects the level of vacuum in the fuel tank. The control module, based on the at least one operating condition, selectively modifies the purge valve leak diagnostic. Selectively modifying the purge valve leak diagnostic includes at least one of preventing the diagnostic module from performing the purge valve leak diagnostic, preventing the diagnostic module from completing the purge valve leak diagnostic, and causing the diagnostic module to indicate that a result of the purge valve leak diagnostic was indeterminate.

Abstract: A control and diagnosis methodology for an electronic module of a vehicle is presented here. In accordance with the disclosed method, at least one wake up event for a processor of the electronic module is performed during an inactive shutdown state of the vehicle. The at least one wake up event is initiated by a wake up timer of the electronic module. The method continues by logging, during the inactive shutdown state of the vehicle, wake up information associated with the at least one wake up event to obtain logged wake up information. The logged wake up information is analyzed during an active operating state of the vehicle to obtain a wake up diagnosis, and the method generates, during the active operating state of the vehicle, an output indicative of the wake up diagnosis.

Abstract: A system includes an ignition detection module, a pressure sensor, a pressure variation module, and a pressure sensor diagnostic module. The ignition detection module detects when an engine is started. The pressure sensor generates a first pressure signal indicating a first pressure within a fuel system of the engine when the engine is started and when a purge valve of the fuel system is closed. The pressure variation module determines an amount of variation in the first pressure signal over a first period. The pressure sensor diagnostic module determines a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period.

Abstract: A control and diagnosis methodology for an electronic module of a vehicle is presented here. In accordance with the disclosed method, at least one wake up event for a processor of the electronic module is performed during an inactive shutdown state of the vehicle. The at least one wake up event is initiated by a wake up timer of the electronic module. The method continues by logging, during the inactive shutdown state of the vehicle, wake up information associated with the at least one wake up event to obtain logged wake up information. The logged wake up information is analyzed during an active operating state of the vehicle to obtain a wake up diagnosis, and the method generates, during the active operating state of the vehicle, an output indicative of the wake up diagnosis.

Abstract: A knock diagnostic module having a knock module that increments a sample count when a cylinder firing signal corresponding to a first cylinder is received and selectively increments a knock count based on a knock detection signal that corresponds to the cylinder firing signal of the first cylinder A knock analysis module analyzes the knock count of the first cylinder when the sample count of the first cylinder reaches a predetermined value and selectively generates an excessive knock signal when the knock count exceeds a predetermined threshold. A remedial action module selectively performs a remedial action based on the excessive knock signal.

Abstract: A method is disclosed for controlling regeneration in a diesel engine after-treatment system having a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF). The method includes injecting an amount of fuel into an exhaust gas flow upstream of the DOC to superheat the gas flow and assessing a rate of the warm-up of the DOC. The method also includes determining, in response to the assessed rate of the warm-up of the DOC, an amount of catalyst substance available in the DOC for catalyzing the exhaust gas flow. The method additionally includes reducing the amount of fuel injected into the DOC such that the determined available amount of catalyst substance is utilized in the DOC for catalyzing the exhaust gas flow and a predetermined amount of fuel is permitted to slip through the DOC to maintain regeneration temperature in the DPF. A system and a vehicle are also disclosed.

Abstract: A method for assessing NO2 generation efficiency in a diesel engine after-treatment (AT) system having a diesel oxidation catalyst (DOC) downstream of the engine generating the NO2 and a selective catalytic reduction (SCR) catalyst downstream of the DOC converting NOX with the aid of the NO2. Engine exhaust gas flow is passed into the AT system and a reductant is injected into the gas flow between the DOC and the SCR catalyst. SCR inlet gas flow temperature is monitored during transient engine operation and DOC inlet and SCR catalyst outlet NOX concentrations are detected when the SCR catalyst inlet gas flow temperature is in a predetermined range. SCR catalyst NOX conversion efficiency is determined using the detected DOC inlet and SCR catalyst outlet concentrations of NOX. Additionally, whether the NO2 generation efficiency is at or above threshold efficiency is assessed by comparing the determined and threshold NOX conversion efficiencies.

Abstract: A system includes an ignition detection module, a pressure sensor, a pressure variation module, and a pressure sensor diagnostic module. The ignition detection module detects when an engine is started. The pressure sensor generates a first pressure signal indicating a first pressure within a fuel system of the engine when the engine is started and when a purge valve of the fuel system is closed. The pressure variation module determines an amount of variation in the first pressure signal over a first period. The pressure sensor diagnostic module determines a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period.

Abstract: A method for diagnosing a device of a vehicle, includes: generating samples of a parameter of the device; indicating whether each of the samples passed or failed based on comparisons of the samples with one of a predetermined value and a predetermined range; tracking a first number of consecutive samples compared, a second number of the first number of samples that failed, a third number of the first number of samples that failed consecutively, and a fourth number of a last predetermined number of samples compared that failed; selecting one of a normal control mode, a temporary default action mode and a permanent default action mode based on the first, second, third, and fourth numbers; and selectively setting a diagnostic trouble code (DTC) in memory when in the permanent default action mode.

Abstract: A method of assessing non-methane hydrocarbon (NMHC) conversion efficiency in a diesel after-treatment (AT) system having a diesel oxidation catalyst (DOC) arranged upstream of a diesel particulate filter (DPF) includes regenerating the AT system. Additionally, the method monitors DOC inlet and outlet temperatures during the regeneration. The method also assesses whether the DOC is operating at or above threshold efficiency by determining a DOC inlet/outlet temperature difference and comparing the determined inlet/outlet temperature difference with a threshold inlet/outlet temperature difference. The method also monitors DPF outlet temperature if the DOC is operating at or above the threshold efficiency and determines a DOC temperature/DPF outlet temperature difference.

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 method for diagnosing a device of a vehicle, includes: generating samples of a parameter of the device; indicating whether each of the samples passed or failed based on comparisons of the samples with one of a predetermined value and a predetermined range; tracking a first number of consecutive samples compared, a second number of the first number of samples that failed, a third number of the first number of samples that failed consecutively, and a fourth number of a last predetermined number of samples compared that failed; selecting one of a normal control mode, a temporary default action mode and a permanent default action mode based on the first, second, third, and fourth numbers; and selectively setting a diagnostic trouble code (DTC) in memory when in the permanent default action mode.

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 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.

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: 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 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 method of assessing non-methane hydrocarbon (NMHC) conversion efficiency in a diesel after-treatment (AT) system having a diesel oxidation catalyst (DOC) arranged upstream of a diesel particulate filter (DPF) includes regenerating the AT system. Additionally, the method monitors DOC inlet and outlet temperatures during the regeneration. The method also assesses whether the DOC is operating at or above threshold efficiency by determining a DOC inlet/outlet temperature difference and comparing the determined inlet/outlet temperature difference with a threshold inlet/outlet temperature difference. The method also monitors DPF outlet temperature if the DOC is operating at or above the threshold efficiency and determines a DOC temperature/DPF outlet temperature difference.

Abstract: A method for assessing NO2 generation efficiency in a diesel engine after-treatment (AT) system having a diesel oxidation catalyst (DOC) downstream of the engine generating the NO2 and a selective catalytic reduction (SCR) catalyst downstream of the DOC converting NOX with the aid of the NO2. Engine exhaust gas flow is passed into the AT system and a reductant is injected into the gas flow between the DOC and the SCR catalyst. SCR inlet gas flow temperature is monitored during transient engine operation and DOC inlet and SCR catalyst outlet NOX concentrations are detected when the SCR catalyst inlet gas flow temperature is in a predetermined range. SCR catalyst NOX conversion efficiency is determined using the detected DOC inlet and SCR catalyst outlet concentrations of NOX. Additionally, whether the NO2 generation efficiency is at or above threshold efficiency is assessed by comparing the determined and threshold NOX conversion efficiencies.