A hybrid electric vehicle system comprises an internal combustion (IC) engine and an electric engine providing power to a drive shaft of the vehicle. The IC engine receives a fuel from a fuel tank. Exhaust gases from the IC engine are treated at an exhaust treatment apparatus including a reagent tank containing a reagent. A controller monitors a quality of the fuel in the fuel tank and the reagent in the reagent tank and if needed, initiates fuel degradation reduction event or a reagent degradation reduction event. These events can include running the IC engine even if a battery supplying power to the motor is not discharged. The fuel degradation reduction event includes dosing the fuel tank with an antioxidant to reduce the rate of degradation of the fuel.

A urea concentration sensor reflector system includes a urea concentration sensor reflector assembly including a reflector having an upwardly convex dome shape integrally connected to and supported by multiple legs. The reflector includes a concave-shaped inner surface. The multiple legs are connected to and support the urea concentration sensor reflector assembly to an upward directed surface of a bottom tank wall of a urea storage tank. A sound wave generator and receiver is fixed to the bottom tank wall directly below and centrally aligned with the reflector. The sound wave generator and receiver generates ultrasonic sound waves directed upwardly toward the reflector. A concentration of a liquid urea in the urea storage tank is determined based on a time for the ultrasonic sound waves to travel to the reflector and return as echo signals to the sound wave generator and receiver, and a temperature of the liquid urea.

Improved systems and methods for dosing agent injection adaptation for a selective catalytic reduction (SCR) system of an engine of a vehicle involve an adaptation procedure that is generally divided into distinct phases based upon the requirement to obtain an accurate dosing adaptation. The phases themselves provide the specific functions of catalyst ammonia storage depletion, catalyst ammonia storage and NOx conversion stabilization, and adaptation value factor determination and verification.

A connection head for being arranged in an orifice of a fluid tank with a return cavity in the form of a radial duct is provided. The return cavity overcomes the problems of the formation of air bubbles in the tank and enhances the functioning of the sensor in the tank.

The present invention relates to a method for calibrating a UWS quality sensor arranged in a motor vehicle. In the method, the calibration of the UWS quality sensor takes place in an installed situation of the UWS quality sensor in the UWS tank.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

A system includes a controller for an exhaust aftertreatment system including a SCR catalyst in exhaust gas-receiving communication with an engine and at least one reductant dosing system structured to provide reductant to the exhaust gas. The controller is structured to determine a ratio of NO to NO.sub.2 at or proximate an inlet of the SCR catalyst. The controller is further structured to command the at least one reductant dosing system to increase, decrease, or maintain an amount of reductant provided to the exhaust gas based on comparing the ratio of NO to NO.sub.2 to a previous NO to NO.sub.2 ratio.

The present invention relates to a method for determining when to correct supply of additive to an exhaust gas stream resulting from combustion in at least one combustion chamber, wherein the additive is arranged for reduction of at least one substance resulting from said combustion by supplying the additive to an exhaust gas stream resulting from said combustion. The quantity of additive being supplied is subjectable to correction, and a sensor is subjected to the exhaust gas stream and arranged to measure occurrence of said at least one substance. The method comprises: by means of sensor signals from said sensor, determining a level of occurrence of said first substance in said exhaust gas stream, and determining when to correct said supply of additive on the basis of said occurrence of said first substance in said exhaust gas stream.

A method includes determining that at least one diesel emissions fluid (DEF) doser of an exhaust aftertreatment system is likely frozen based on at least one of an ambient air temperature or a DEF source temperature; operating an engine in a cylinder cutout mode in response to the determination that the at least one DEF doser is likely frozen; and, discontinuing the cylinder cutout mode in response to determining that the at least one DEF doser is in a predefined condition.

A method for diagnosing a quality signal (26). The quality signal (26) is provided by a quality sensor (24) used in a reagent metering system (10). The reagent metering system (10) meters a urea/water solution (14) stored in a tank (12), the quality of which is checked by the quality sensor (24), upstream of an SCR catalytic converter (20).