NOx SENSOR [SKYACTIV-D 1.8]
id0140s1011100
Purpose/Function
• The NOx sensor detects NOx after it passes through the catalytic converter (oxidiation catalyst/NOx strage catalyst) and inputs NOx to the PCM via CAN.
Construction
• The gas detection area (probe) of the NOx sensor is installed to the rear of the catalytic converter (DPF).
• The NOx sensor (control unit) of the NOx sensor is secured to the bracket under the floor.
• The NOx sensor (control unit) is integrated with the probe and therefore cannot be disconnected.
• A zirconia element has been adopted for the detection part of the NOx sensor.
Operation
• From engine start and before start of measurement:
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― It operates the heater at low temperature and waits (because damage may occur if element contacts water)
• Measurement start:
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― It increases the heater temperature to the condition possible for measurement when the dew point end signal is input from the PCM the CAN.
• During measurement:
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― The NOx sensor maintains the element temperature at a high temperature condition, and sends the measured value to the 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.
