Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

A method of controlling a rate of warm-up of an internal combustion engine fluidly connected to an exhaust system is disclosed. The method includes identifying a cold-start of the engine. The method also includes regulating, in response to the identified cold-start of the engine, an exhaust pressure modulation (EPM) valve arranged in a main exhaust passage of the exhaust system. The main exhaust passage channels engine exhaust gas to the ambient. Such regulation of the EPM valve will restrict a flow of the engine exhaust gas to the ambient and increase exhaust gas backpressure in the exhaust system up to a predetermined pressure value. Furthermore, the subject regulation of the EPM valve will increase a load on and the rate of warm-up of the engine. A vehicle having an engine and a controller programmed to control a rate of the engine's warm-up of according to the method is also disclosed.

Embodiments for diagnosing a humidity sensor are provided. One example method comprises, responsive to a humidity sensor test cycle, pumping air conditioning and windshield washer gas flows past a humidity sensor, and indicating humidity sensor degradation based on a response of the humidity sensor to the air conditioning and windshield washer gas flows. In this way, degradation of the humidity sensor may be indicated if the humidity sensed by the humidity sensor does not change responsive to the humidity sensor test cycle being initiated.

The invention relates to a method for a vehicle system (100) comprising an internal combustion engine (10) having a turbocharger unit (110) connected thereto, a turbocompound unit (120) arranged to receive exhaust gas flowing from the turbocharger unit (110), and an exhaust gas recirculation system (130). The method comprises controlling the exhaust gas flowing through the exhaust gas recirculation system (130) by determining a pressure difference, and, if the determined pressure difference is above a predetermined threshold value directing the recirculated exhaust gas to an air intake line (160) downstream a charge air cooler (170), and, if the determined pressure difference is not above the predetermined threshold value directing the recirculated exhaust gas to a compressor (114) of the turbocharger unit (110).

Methods and systems for an engine intake system are provided. In one example, a system includes a first charge air cooler arranged upstream of a second charge air cooler. The first charge air cooler is configured to provide thermal transfer between a compressed charge air and a fresh intake air.

Methods and systems for an engine intake system are provided. In one example, a system includes a first charge air cooler arranged upstream of a second charge air cooler. The first charge air cooler is configured to provide thermal transfer between a compressed charge air and a fresh intake air.

A housing has an outer pipe, an inner pipe, and an EGR inlet. The inner pipe is located inside the outer pipe. The inner pipe defines an inner passage internally. The inner pipe defines an annular passage externally with the outer pipe. The EGR inlet defines an EGR channel therein to communicate with the annular passage. The inner pipe has an end surface defining a throttle passage extending circumferentially. The throttle passage communicates the annular passage with the inner passage radially inward. The throttle passage is narrow on a side of the EGR channel and is wide on an opposite side of the EGR channel.

A housing has an outer pipe, an inner pipe, and an EGR inlet. The inner pipe is located inside the outer pipe. The inner pipe defines an inner passage internally. The inner pipe defines an annular passage externally with the outer pipe. The EGR inlet defines an EGR channel therein to communicate with the annular passage. The inner pipe has an end surface defining a throttle passage extending circumferentially. The throttle passage communicates the annular passage with the inner passage radially inward. The throttle passage is narrow on a side of the EGR channel and is wide on an opposite side of the EGR channel.

An EGR valve is provided in an EGR passage circulating a part of an exhaust gas of an exhaust pipe in an intake pipe as an EGR gas, the EGR valve adjusting an EGR gas amount flowing in the EGR passage when an engine is in an EGR region, a differential pressure device is provided in the intake pipe, the differential pressure device adjusting a differential pressure of the EGR valve, a control unit is provided to control the EGR valve and the differential pressure device, and the EGR control method includes switching whether to adjust the EGR gas amount using the EGR valve and the differential pressure device or to adjust the EGR gas amount using the EGR valve only on the basis of an exhaust gas pressure of an inlet portion of the EGR passage.

An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.