EGR Volume Control
The EGR volume control regulates the flow rate of exhaust gas flowing from downstream of exhaust manifold catalyst to intake manifold. The exhaust gas flow rate is controlled by opening/closing the EGR path in the EGR control valve.
A built-in DC motor moves the valve continuously corresponding to the ECM output signal.
The EGR volume control valve position sensor detects the valve position and sends the voltage signals to the ECM.
The adoption of water-cooled EGR cooler reduces the knocking by efficiently cooling the gas circulated by the EGR system to lower the combustion temperature and improves fuel efficiency by raising the thermal efficiency.
The ECM judges the current opening angle of the valve from this signals and the ECM controls the DC motor to make the valve opening angle properly.
The opening angle of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions.
The EGR volume control valve remains close under the following conditions.
- Engine stopped
- Engine starting
- Low engine coolant temperature
- Excessively high engine coolant temperature
- High engine speed
- Accelerator pedal fully depressed
- Low intake air temperature