IDLE SPEED CONTROL [SKYACTIV-D 2.2]
id0140z7952300
Outline
• The PCM controls the fuel injection amount so that the target idle speed according to the engine operation conditions is obtained
Block diagram
Operation
• The fuel injection amount is controlled so that the actual idle speed is close to the target idle speed.
• The target idle speed is set under various conditions and consists mainly of the following control items.
Item
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Control description
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Target idle speed
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Feedback Control
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The actual idle speed conforms to the target idle speed during normal idling.
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800 rpm
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Engine speed control during fuel injection cleaning*1
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While in the P/N position during fuel injection cleaning, controls the engine speed so that it matches the target engine speed.
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1,500 rpm
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Engine speed control during fuel injection amount learning
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During fuel injection amount learning, the engine speed is controlled so that it matches the target engine speed.
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During manual learning control
2,000 rpm
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DPF regeneration control
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Controls the engine speed during DPF regeneration control so that it matches the target engine speed.
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Auto DPF regeneration
780―875 rpm
Compulsory DPF regeneration
1,750 rpm*2
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*1 :The PCM implements fuel injection control when it determines that the ignition switch is being switched OFF repeatedly while the engine has not been warmed up sufficiently. The accumulation of condensation in the fuel injection system is prevented by increasing the idle speed under no-load conditions and the temperature in the combustion chamber. When the temperature in the combustion chamber increases to the specified temperature, idle speed increase is automatically canceled.
*2 :If there is incorrect combustion of soot during diesel particulate filter regeneration, the exhaust gas temperature increases which may cause damage to the diesel particulate filter. In this case, post injection is stopped and the engine speed increases to 2,500 rpm. Due to this, low temperature exhaust gas is sent to the oxidation catalytic converter at high speed and the diesel particulate filter is cooled to prevent damage.
• The A/C operation information from the A/C pressure sensor is input to prevent the idle speed from decreasing by A/C load. The fuel injection amount is corrected to maintain idle speed when the A/C load is applied.
In addition, the fuel injection amount is corrected to prevent a decrease in speed when the electrical load is applied.