Abstract: Methods and systems are provided for EGR valve diagnostic. In one example, a method includes providing a correction to a position of the EGR valve to compensate for an altitude of the vehicle. The compensation is based on a comparison of a pressure ratio to a curve rationalized with a barometric pressure.

Abstract: Systems and methods for determining whether or not a temperature sensor is degraded are presented. In one example, a determination of degradation of the temperature sensor is based on a difference between a temperature determined from output of the temperature sensor and an estimate of a temperature of a pressure sensor.

Abstract: Methods and systems are provided for diagnostics of exhaust gas recirculation (EGR) components including an EGR pressure sensor. In one example, a method for an exhaust gas recirculation (EGR) system of a vehicle comprises diagnosing an excessive EGR flow rate via an MAP-MAF strategy, the MAP-MAF strategy including estimating an EGR flow rate based on a difference between an output of a manifold absolute pressure (MAP) sensor of the vehicle and an output of a mass airflow (MAF) sensor of the vehicle; and in response to stable intrusive conditions being met, intrusively commanding an EGR valve of the EGR system to a closed position to confirm the diagnosed excessive EGR flow rate. If the excessive flow is detected after the EGR valve is commanded to the closed position, a diagnostic code may be set.

Abstract: Methods and systems are provided for diagnostics of exhaust gas recirculation (EGR) components including an EGR pressure sensor. In one example, a method may include comparing a current relationship between an output of the EGR pressure sensor and a manifold air pressure (MAP) and a pre-calibrated relation between the output of the EGR pressure sensor and the MAP to detect degradation of the EGR pressure sensor.

Abstract: Methods and systems are provided for diagnostics of exhaust gas recirculation (EGR) components including an EGR pressure sensor. In one example, a method may include comparing a current relationship between an output of the EGR pressure sensor and a manifold air pressure (MAP) and a pre-calibrated relation between the output of the EGR pressure sensor and the MAP to detect degradation of the EGR pressure sensor.

Abstract: Methods and systems are provided for a high-pressure exhaust gas recirculation system. In one example, the high-pressure exhaust gas recirculation system comprises pressure seconds arranged on different sides of a valve. The pressure sensors are used to regulate exhaust-gas recirculate flow without a fixed orifice delta pressure sensor.

Abstract: Methods and systems are provided for a high-pressure exhaust gas recirculation system. In one example, the high-pressure exhaust gas recirculation system comprises pressure seconds arranged on different sides of a valve. The pressure sensors are used to regulate exhaust-gas recirculate flow without a fixed orifice delta pressure sensor.

Abstract: Methods and systems are provided for diagnosing a humidity sensor in an engine. In one example, a method may include heating intake air entering an intake passage of an engine using heat recirculated from an exhaust system of the engine. A response of the humidity sensor to the heating of the intake air may be used to assess an integrity of the humidity sensor.

Abstract: Methods and systems are provided for a high-pressure exhaust gas recirculation system. In one example, the high-pressure exhaust gas recirculation system comprises pressure sensors arranged on different sides of an EGR valve. Feedback from the pressure sensors are used to diagnose a EGR valve position sensor.