SCR CONTROL [SKYACTIV-D 2.2]

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With SCR system

Purpose, Function

•  The dosing control unit injects AdBlue^® to the exhaust pipe to purify NOx in the exhaust gas.

•  The dosing control unit performs coordinated control with the PCM to inject the appropriate AdBlue^® amount.

•  AdBlue^® is warmed by the heater in the urea tank to defrost it and prevent it from freezing.

•  The PCM alerts the driver of the warning via the instrument cluster if there is low or excess AdBlue^® or fluid other than normal AdBlue^® is in the tank, or the SCR system is not operating properly.

Block diagram

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Operation

•  When the SCR catalyst temperature exceeds 165 °C {329 °F} and the NOx sensor detects NOx, the AdBlue^® injection function operates according to the purification rate in the catalyst.

•  When the AdBlue^® temperature is -3 °C {27 °F} or less or the ambient temperature is -3 °C {27 °F} or less, the heater function operates.

•  The warning function operates if there is low or excess AdBlue^® or fluid other than normal AdBlue^® is in the tank, or there is a malfunction in the SCR system.