EGR System - Diesel: Operation
The EGR flow is determined by position of throttle and EGR valves. Information is signaled to EGR control unit by potentiometer (engine load), revolution sensor (engine RPM) and water temperature sensor (engine coolant).
The control unit signals the solenoid valves to open or close, determining vacuum levels at EGR control valve and throttle diaphragm. To assure good driveability and safe operation, the EGR system is deactivated when coolant temperature is either low or extremely high.
EGR SYSTEM OPERATION (MAXIMA)
| Throttle Valve Position | EGR Valve Position | EGR Flow Rate |
|---|---|---|
| Closed | Open | High |
| Open | Open | Low |
| Open | Closed | Zero |
EGR SYSTEM OPERATION (SENTRA)
| Throttle Valve Position | EGR Valve Position | EGR Flow Rate | |
|---|---|---|---|
| Low Altitude | |||
| Closed | Open | High | |
| Open | Open | Low | |
| Open | Closed | Zero | |
| High Altitude | |||
| Open | Open | Low | |
| Open | Open | Low | |
| Open | Closed | Zero | |