EGR malfunction detection system

An EGR malfunction detection system comprising:

• an EGR valve configured to open and close an exhaust recirculation path for recirculating an exhaust gas from an exhaust channel to an intake channel of an engine;
• a valve controller configured to control the EGR valve;
• an intake pressure sensor configured to measure a first intake pressure inside the intake channel when the EGR valve is controlled to be in a closed state by the valve controller, and measure a second intake pressure inside the intake channel when the EGR valve is controlled to be in an open state by the valve controller;
• and
• a processor configured to detect an anomaly in the exhaust recirculation path in accordance with an output from the intake pressures sensor and an output from the valve controller, wherein
• the processor determines that the EGR valve is stuck in an open state and outputs a first signal indicating that the EGR valve is stuck in the open state, when the first intake pressure is larger than a first threshold and the second intake pressure is larger than a second threshold that is larger than the first threshold,
• the processor determines that the EGR valve is stuck in the closed state and outputs a second signal indicating that the EGR valve is stuck in the closed state, when the first intake pressure is smaller than the first threshold and the second intake pressure is smaller than the second threshold, and
• the processor determines that the EGR valve is stuck in an intermediate state and outputs both the first signal and the second signal indicating that the EGR valve is stuck in the intermediate state, when the first intake pressure is larger than the first threshold and the second intake pressure is smaller than the second threshold.