Detroit Diesel Electronic Controls The Common Rail Fuel System consists of several sensors used to evaluate its own performance. These sensors are; high fuel pressure, low fuel pressure and fuel temperature, which are located on the high-pressure fuel pump as shown in Fig. 10. The low fuel pressure sensor provides information on the availability of low- pressure fuel being supplied to the high-pressure pump. The high fuel pressure sensor provides information on the fuel pressure within the high-pressure rails available for injection. The fuel temperature sensor provides information on the temperature of the fuel being supplied to protect the ECM’s and high-pressure fuel pump.
HIGH-PRESSURE FUEL PUMP DDEC HARNESS CONNECTION TO HP PUMPCONTROL SOLENOID (24- VOLT SUPPLY) LOW-PRESSURE FUEL PRESSURE SENSOR HIGH-PRESSURE PUMP CONTROL SOLENOID HIGH-PRESSURE FUEL RAIL PRESSURE SENSOR FUEL TEMPERATURE SENSOR Fig. 10 High-pressure Pump Sensor Locations. The high-pressure fuel pump receives low-pressure fuel from the fuel delivery pump and controls the high-pressure fuel output with the control solenoid, which receives input from the Master ECM and provides feedback information to the Master ECM. This input and output can be read with a DDR as PWM3 and Injection Pump Usage (Refer to Fig. 11). The normal PWM3 operating range is 8-52%.
Injection pump usage operates between 2% and 98% range. The normal injection pump usage at 100% engine load is in the 45-65% range at 1900 RPM. The control solenoid operates on 24 Volts DC with a fuse located in the OEM supplied power circuit. Page 10