Methods and systems are provided for an EGR system reverse hose diagnostic. In one example, a method includes executing the reverse hose diagnostic in response to an EGR flowrate exceeding a threshold flow rate.

Methods and systems are provided for an EGR system reverse hose diagnostic. In one example, a method includes executing the reverse hose diagnostic in response to an EGR flowrate exceeding a threshold flow rate.

Methods and systems are provided for an EGR system reverse hose diagnostic. In one example, a method includes executing the reverse hose diagnostic in response to an EGR flowrate exceeding a threshold flow rate.

A switching finger follower for an engine valve train utilizes an adjustable support assembly that eliminates potential for partial engagement during operation. A lever engagement member or latch is disposed for movement on the follower body and interacts with a lever to provide a constant contact geometry. The finger follower may be configured as a lost motion device and may include a biasing assembly and a travel limiter. The latch may support the lever in at least one precise position and may support the lever in a second position for partial lost motion, or permit the lever to pivot free of the latch for complete lost motion, as in cylinder deactivation applications.

A switching finger follower for an engine valve train utilizes an adjustable support assembly that eliminates potential for partial engagement during operation. A lever engagement member or latch is disposed for movement on the follower body and interacts with a lever to provide a constant contact geometry. The finger follower may be configured as a lost motion device and may include a biasing assembly and a travel limiter. The latch may support the lever in at least one precise position and may support the lever in a second position for partial lost motion, or permit the lever to pivot free of the latch for complete lost motion, as in cylinder deactivation applications.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, and an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, and a downstream passage connected to the first upstream passage and the second upstream passage, and provided downstream with respect to the first upstream passage and the second upstream passage. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage and rotates around an EGR valve axis to open and close the downstream passage.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, and an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, and a downstream passage connected to the first upstream passage and the second upstream passage, and provided downstream with respect to the first upstream passage and the second upstream passage. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage and rotates around an EGR valve axis to open and close the downstream passage.

An EGR device for a vehicle includes a valve driver, a pressure comparison unit, a freeze determination unit, and an EGR controller. The valve driver drives an EGR valve to open, when fuel cut has been continued for a predetermined time in a state where an engine speed of a vehicle's engine is equal to or higher than a predetermined rotational speed. The pressure comparison unit compares a pre-driving pressure of an engine's intake pipe with a post-driving pressure of the intake pipe. The freeze determination unit sets a flag indicating that the EGR valve is frozen when a difference between the pre-driving pressure and the post-driving pressure is less than a predetermined value and an external temperature is less than a threshold. When the flag has been set, the EGR controller sets a control state of the EGR valve to a closed state and stops EGR control.

An EGR device for a vehicle includes a valve driver, a pressure comparison unit, a freeze determination unit, and an EGR controller. The valve driver drives an EGR valve to open, when fuel cut has been continued for a predetermined time in a state where an engine speed of a vehicle's engine is equal to or higher than a predetermined rotational speed. The pressure comparison unit compares a pre-driving pressure of an engine's intake pipe with a post-driving pressure of the intake pipe. The freeze determination unit sets a flag indicating that the EGR valve is frozen when a difference between the pre-driving pressure and the post-driving pressure is less than a predetermined value and an external temperature is less than a threshold. When the flag has been set, the EGR controller sets a control state of the EGR valve to a closed state and stops EGR control.

Provided is an internal combustion engine control unit that controls an engine by detecting combustion characteristics with a simple configuration robust to disturbance such as noise. Therefore, the internal combustion engine control unit (ECU 12) of the present embodiment includes a rotational speed calculation unit 122a that calculates a crank rotational speed of an internal combustion engine (engine 1); an extreme value timing calculation unit 122b that calculates an extreme value timing of the crank rotational speed calculated by the rotational speed calculation unit 122a; and a combustion state estimation unit (combustion phase calculation unit 122c) that estimates a combustion state based on the extreme value timing of the crank speed calculated by the extreme value timing calculation unit 122b.