FUNCTION OF MAIN COMPONETS
The main components of the emission control system are as follows:
| Component | Outline | Quantity | Function |
|---|---|---|---|
| ECM | 32-bit CPU | 1 | Effects overall control of the emission control system to suit the operating conditions of the engine in accordance with the signals provided by the sensors. |
| 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. |
| 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 catalyst to detect whether the DPF catalyst is clogged. |
| Exhaust Gas Temperature Sensor Assembies | Thermistor Type | 3 | Located before and after the DPF catalyst and detect the temperature of the DPF catalyst. |
| Air Fuel Ratio Sensor | Heated Type (Planar Type) | 1 | Detects the oxygen concentration in the exhaust gas. |
SYSTEM CONTROL
The emission control system has the following systems:
| System | Outline |
|---|---|
| Catalyst Support Control | Based on the signals received from the sensors, the ECM controls the exhaust fuel addition injector to purify the Particulate Matter (PM). |
| 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. |
FUNCTION
Catalyst Support Control
The ECM judges the exhaust manifold converter condition based on signals from the mass air flow meter, engine coolant temperature sensor, 3 exhaust gas temperature sensors, differential pressure sensor and air fuel ratio sensor to control the injectors and exhaust fuel addition injector for catalyst support control.
EGR Control
This system is designed to help reduce and control NOx formation 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.