EGR CONTROL [SKYACTIV-G 1.5 (WITH EGR COOLER)]SM3020936
EGR CONTROL [SKYACTIV-G 1.5 (WITH EGR COOLER)]
id0140q11614k1
Outline
• To perform optimum control according to the engine operation conditions, the EGR valve is opened and the exhaust gas is recirculated based on information such as the estimated exhaust gas pressure and information from the MAP sensor.
• The intake gas temperature increases or decreases rapidly according to the exhaust gas temperature, and it affects the combustion temperature. To optimize the temperature of the recirculated exhaust gas, the opening and closing of the EGR valve are controlled according to the engine coolant temperature.
Block Diagram
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Operation
Target EGR valve opening angle calculation method
• The PCM determines the target opening angle of the EGR valve using the following method.
1.The PCM determines the target EGR rate so that the EGR volume is optimized according to the engine operation conditions. The target EGR rate is calculated based on the basic EGR rate.
Basic EGR rate
• The EGR rate is calculated according to the engine speed and the charging efficiency
*1.
*1:Charging efficiency is the ratio of the actual amount of intake air to the maximum air charging amount (mass volume) of the cylinder. This value increases proportionately to the increase in engine load.
2.The PCM determines the target EGR flow amount so that the target EGR rate is achieved.
Target EGR flow amount
• Calculated based on information such as the engine speed and the intake air amount.
3.The PCM calculates the target EGR valve opening angle to achieve the target EGR flow amount.
Target EGR valve opening angle
• Calculated based on information such as the estimated exhaust gas pressure and information from the MAP sensor.
4.The PCM controls the EGR valve by feedback control using the EGR valve position sensor to achieve the target EGR valve opening angle.
Inhibition conditions
• To improve drive ability and ensure exhaust emission performance, the EGR valve fully closes when any of the following conditions is met.
― Ignition is switched OFF or ignition is switched to ACC or ON (engine off)