Abstract: A system for an engine to determine in situ under specified conditions the auto-ignition quality of the fuel used in a compression ignition engine is provided. The system may include an ion current sensor. The ion current sensor may access an engine cylinder for obtaining ion current data. A control unit may be in communication with the ion current sensor for receiving the ion current data. The control unit being configured to determine the auto-ignition quality of the fuel based on features of the ion current data.

Abstract: A system for an engine to determine in situ under specified conditions the auto-ignition quality of the fuel used in a compression ignition engine is provided. The system may include an ion current sensor. The ion current sensor may access an engine cylinder for obtaining ion current data. A control unit may be in communication with the ion current sensor for receiving the ion current data. The control unit being configured to determine the auto-ignition quality of the fuel based on features of the ion current data.

Abstract: A vehicle diagnostics clearing system that detects a clear diagnostic faults flag and clears diagnostic faults from a control module includes a clear diagnostic faults flag monitoring module and a clear diagnostic faults module. The clear diagnostic faults flag monitoring module periodically monitors the clear diagnostic faults flag in the control module. When the clear diagnostic faults flag monitoring module detects that the clear diagnostic faults flag is set, the clear diagnostic faults module clears the diagnostic faults from the control module for a predetermined period.

Abstract: An engine control system that regulates operating of an engine of a motor vehicle includes a first module that determines whether a throttle of the motor vehicle is closed and a second module that determines whether the engine is idling while a cruise control is active. A third module selectively inhibits an RPM-based idle speed control of the engine if the throttle is closed and the engine is idling while the cruise control is active.

Abstract: An engine fault diagnostic system includes a diagnostic module that generates a manifold absolute pressure (MAP) error signal and that generates a mass air flow (MAF) error signal. A security module generates an air flow fault when the MAP error signal exceeds a MAP threshold and the MAF error signal exceeds a MAF threshold.

Abstract: An engine control system includes an ignition switch that selectively initiates an ignition signal and an operating mode of an engine. A powertrain relay selectively generates a PR load signal based on the ignition signal and the operating mode. A control module enables an ignition signal diagnostic system when the operating mode is a RUN mode, the ignition signal is generated and the PR load signal is generated.

Abstract: A controller estimates a temperature of a catalytic converter in a vehicle and determines an engine speed. The controller shuts off fuel to the engine if the estimated temperature is greater than a maximum temperature of the catalytic converter and the engine speed is greater than a maximum engine speed. If the estimated catalytic converter temperature is greater than the maximum temperature, the controller delays a spark retard request to the engine. The controller updates vehicle torque with an integral torque if an RPM error is within an RPM error range and vehicle speed is less than a maximum vehicle speed for a first period. The controller increases torque to the engine by a proportional torque if an RPM error is within an RPM error range to prevent engine stall. The controller updates the integral torque when the RPM error is within an RPM error range for a first period.