Abstract: An intake air temperature (IAT) sensor diagnostic module comprises a measured noise module, an expected noise module, an excess noise module, and an IAT fault detection module. The measured noise module measures noise in an IAT signal from an IAT sensor in a vehicle. The expected noise module determines expected noise based upon the IAT signal. The excess noise module determines an excess noise value based upon the measured noise and the expected noise. The IAT fault detection module diagnoses faults in the IAT sensor based upon a comparison of the excess noise value and a first predetermined value.

Abstract: A method of determining a barometric pressure of atmosphere, in which an internal combustion engine of a vehicle is located includes monitoring operating parameters of the internal combustion engine and the vehicle, determining a healthy status of an air filter of the internal combustion engine, and calculating the barometric pressure based on the operating parameters and the healthy status of the air filter.

Abstract: A diagnostic cold start emissions control system for an internal combustion engine includes a control module having a calculated engine-out energy module, an engine-out energy residual module, and a diagnostic system evaluation module. The calculated engine-out energy module is in communication with the engine-out energy residual module and is configured to determine an operating engine-out energy flow based on an operating engine torque. The engine-out energy residual module is in communication with the diagnostic system evaluation module and is configured to determine an engine-out energy residual based on the determined engine-out energy flow and an expected engine-out energy flow. The diagnostic system evaluation module is configured to determine whether the determined engine-out energy residual meets a predetermined value indicative of proper cold start emissions control.

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 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: An intake air temperature (IAT) sensor diagnostic module comprises a measured noise module, an expected noise module, an excess noise module, and an IAT fault detection module. The measured noise module measures noise in an IAT signal from an IAT sensor in a vehicle. The expected noise module determines expected noise based upon the IAT signal. The excess noise module determines an excess noise value based upon the measured noise and the expected noise. The IAT fault detection module diagnoses faults in the IAT sensor based upon a comparison of the excess noise value and a first predetermined value.

Abstract: A method of correlating a rotational position of a crankshaft to a rotational position of a camshaft includes determining a stretch value of a timing connection, which drivingly couples the crankshaft and the camshaft, and calculating a crankshaft to camshaft rotational position value indicative of the rotational position of the crankshaft with respect to the rotational position of the camshaft. The crankshaft to camshaft rotational position value is compensated based on the stretch value to provide a compensated crankshaft to camshaft rotational position value and whether the rotational position of the crankshaft correlates to the rotational position of the camshaft is determined based on the compensated crankshaft to camshaft rotational position value.

Abstract: A method of determining a barometric pressure of atmosphere, in which an internal combustion engine of a vehicle is located includes monitoring operating parameters of the internal combustion engine and the vehicle, determining a healthy status of an air filter of the internal combustion engine, and calculating the barometric pressure based on the operating parameters and the healthy status of the air filter.

Abstract: A method of correlating a rotational position of a crankshaft to a rotational position of a camshaft includes determining a stretch value of a timing connection, which drivingly couples the crankshaft and the camshaft, and calculating a crankshaft to camshaft rotational position value indicative of the rotational position of the crankshaft with respect to the rotational position of the camshaft. The crankshaft to camshaft rotational position value is compensated based on the stretch value to provide a compensated crankshaft to camshaft rotational position value and whether the rotational position of the crankshaft correlates to the rotational position of the camshaft is determined based on the compensated crankshaft to camshaft rotational position value.

Abstract: A vacuum signal diagnostic system that diagnoses operation of a vacuum sensor of a brake booster system that is in fluid communication with an engine includes a first module that determines whether a vacuum signal of the vacuum sensor is increasing and a second module that compares an engine vacuum signal of the engine to the vacuum signal. A third module indicates a HI fault of the vacuum sensor when the vacuum sensor is increasing and a difference between the engine vacuum signal and the vacuum signal is greater than zero for a first threshold time.

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 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 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 diagnostic cold start emissions control system for an internal combustion engine includes a control module having a calculated engine-out energy module, an engine-out energy residual module, and a diagnostic system evaluation module. The calculated engine-out energy module is in communication with the engine-out energy residual module and is configured to determine an operating engine-out energy flow based on an operating engine torque. The engine-out energy residual module is in communication with the diagnostic system evaluation module and is configured to determine an engine-out energy residual based on the determined engine-out energy flow and an expected engine-out energy flow. The diagnostic system evaluation module is configured to determine whether the determined engine-out energy residual meets a predetermined value indicative of proper cold start emissions control.

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: Methods, systems and devices for identifying irrational results from an engine coolant temperature (ECT) sensor in a vehicle are described. The vehicle suitably includes a processor in communication with the ECT sensor and an intake air temperature (IAT) sensor. The method includes the steps of receiving an ECT reading from the ECT sensor and a IAT reading at the processor, evaluating a temperature difference between the ECT reading and the IAT reading to determine if irrationality is present, and providing a fault indication in response to the evaluating step. The evaluating step includes monitoring the IAT reading during operation of the vehicle to identify the presence of an engine block heater if the temperature difference exceeds a pre-determined threshold.

Abstract: A method and control system for verifying cold start emissions reduction control in a vehicle using an internal combustion engine utilizes measured engine speed and commanded ignition timing to calculate an estimated actual engine-out thermal energy flow. An expected thermal energy flow is calculated based on designed engine speed and ignition timing. A residual energy flow is calculated based on a difference between the estimated actual thermal energy flow and the expected thermal energy flow. Meanwhile, a system quality-weighting factor is calculated based on several measured engine parameters. A qualified energy flow residual is calculated based on the system quality weight and the residual energy flow. The qualified energy residual flow is accumulated, averaged based on the accumulated quality weight, and then filtered.

Abstract: A process for computer based, wholly passive, diagnosis of an automotive vehicle exhaust gas recirculation system is disclosed. Use is made of any suitable math model of the vehicle's air intake system to estimate the absolute pressure in the intake manifold, MAP, assuming both a healthy EGR system, MAPHE, and a faulty EGR valve, MAPFE. Both estimated values are compared with the actual normally measured manifold pressure, MAPmeas. Both comparisons are repeated over many calculations and the differences analyzed to reliably determine whether there is a real restriction to recirculated exhaust flow. A preferred math model of the intake system uses as input variables: mass air flow, barometric pressure, the position command for the EGR valve and engine speed.

Abstract: A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model and correctly identifies faults in the TPS, the MAP sensor and the MAF sensor. The throttle model generates a mass airflow estimate. The first intake model generates a first MAP estimate. The second intake model generates a second MAP estimate. The diagnostic controller applies residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller applies a first order lag filter on the residual calculations. The diagnostic controller accesses a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.

Abstract: A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model and correctly identifies faults in the TPS, the MAP sensor and the MAF sensor. The throttle model generates a mass airflow estimate. The first intake model generates a first MAP estimate. The second intake model generates a second MAP estimate. The diagnostic controller applies residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller applies a first order lag filter on the residual calculations. The diagnostic controller accesses a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.