EMISSION CONTROL SYSTEM


  1. FUNCTION OF MAIN COMPONETS


    1. The main components of the catalyst support control are as follows (Models with DPF Catalyst):

      Component Outline Quantity Function
      ECM 32-bit CPU 1 Controls the catalyst support control based on signals from each sensor.
      Exhaust Fuel Addition Injector Solenoid Type 1 Injects fuel into the exhaust port.
      Differential Pressure Sensor Assembly Semiconductor Strain Gauge Type 1

      • Monitors the differential pressure before and after the DPF.

      • Compares this data with the PM accumulation amount calculated by the ECM. If there is a large deviation in the comparison result, the ECM corrects the PM accumulation amount.
      Exhaust Gas Temperature Sensor Assemblies Thermistor Type 2 Detects the exhaust gas temperature.
      Air Fuel Ratio Sensor Heated Type (Planar Type) 1 Detects the oxygen concentration in exhaust gas.

    2. The main components of the EGR system are as follows:

      Component Outline Quantity Function
      ECM 32-bit CPU 1 Controls the EGR system based on signals from each sensor.
      EGR Valve DC Motor Type 1 Actuated by the ECM and controls the flow rate of EGR gas.
      EGR Cooler Water-cooled Type 1 Cools EGR gas.

  2. SYSTEM CONTROL


    1. The emission control system has the following systems:

      System Outline
      Catalyst Support Control*

      • In order to comply with emission regulations, a Diesel Particulate Filter (DPF) catalyst is used to effectively collect and purify CO, HC and Particulate Matter (PM) contained in exhaust gas.

      • Due to the use of the DPF, catalyst support control that combusts and purges PM accumulated in the DPF is used for DPF regeneration.
      Air Fuel Ratio Sensor Heater Control* Maintains the temperature of the air fuel ratio sensor at an appropriate level to increase accuracy of detection of the oxygen concentration in exhaust gas.
      EGR Control Based on the signals received from the sensors, the ECM determines the EGR volume via the EGR valve and EGR cooler bypass valve in accordance with the engine condition.

      *: Models with DPF Catalyst

  3. FUNCTION


    1. Catalyst Support Control (Models with DPF Catalyst)


      1. When an extremely large amount of PM is accumulated in the DPF, the back pressure of the engine increases and the PM is combusted at once, potentially damaging the filter. In order to prevent that, it is necessary to forcibly combust the accumulated PM. Therefore, the accumulated PM is combusted by increasing the temperature of the filter.

      2. If the temperature of the DPF does not increase and the PM keeps accumulating in the DPF, a message is displayed on the multi-information display to notify the driver.

    2. EGR Control


      1. This system is designed to help reduce and control NOxformation due to a reduction of peak temperature in the engine combustion chamber, which is accomplished by the introduction of amount of inert gas into the intake manifold.