NOx SENSOR [SKYACTIV-D 2.2]

id0140z7011100

NOx SENSOR No.1

Purpose, Function

•  The NOx sensor No.1 detects NOx after it passes through the catalytic converter (diesel particulate filter) and inputs NOx to the dosing control unit and PCM via CAN.

Construction

•  The gas detection area (probe) of the NOx sensor No.1 is installed to the rear of the catalytic converter.

•  The NOx sensor No.1 (control unit) of the NOx sensor No.1 is secured to the bracket under the floor.

•  The NOx sensor No.1 (control unit) is integrated with the probe and therefore cannot be disconnected.

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Operation

•  From engine start and before start of measurement:

―  It operates the heater at low temperature and waits (because damage may occur if element contacts water)

•  Measurement start:

―  It increases the heater temperature to the condition possible for measurement when the dew point end signal is input from the dosing control unit via the CAN.

•  During measurement:

―  The NOx sensor No.1 maintains the element temperature at a high temperature condition, and sends the measured value to the dosing control unit and PCM via CAN.

―  It continues the measurement unless a malfunction is detected or a power supply malfunction occurs.

•  It performs the malfunction diagnosis just after the ignition is switched OFF.

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Fail-safe

NOx SENSOR No.2

Purpose, Function

•  The NOx sensor No.2 detects NOx after passing it through the SCR converter and inputs NOx to the dosing control unit via a CAN signal.

Construction

•  The NOx sensor No.2 is installed to the rear of the SCR converter.

•  The NOx sensor No.2 (control unit) of the NOx sensor No.2 is secured to the bracket under the floor.

•  The NOx sensor No.2 (control unit) is integrated with the probe and therefore cannot be disconnected.

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Operation

•  From engine start and before start of measurement:

―  It operates the heater at low temperature and waits (because damage may occur if element contacts water)

•  Measurement start:

―  It increases the heater temperature to the condition possible for measurement when the dew point end signal is input from the dosing control unit via the CAN.

•  During measurement:

―  The NOx sensor No.2 maintains the element temperature at a high temperature condition, and sends the measured value to the dosing control unit and PCM via CAN.

―  It continues the measurement unless a malfunction is detected or a power supply malfunction occurs.

•  It performs the malfunction diagnosis just after the ignition is switched OFF.

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Fail-safe