Fuel Pressure And Temperature Sensor
The fuel pressure and temperature sensor monitors both pressure and temperature of the low pressure fuel system. The temperature component of the sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical voltage signals to the PCM corresponding to temperature. The pressure component of the sensor provides a signal to the PCM indicating low pressure fuel system pressure. The PCM supplies a 5 volt reference (VREF) signal, as well as supplying 5 volts on the FLP circuit. As pressure increases, the sensor signal voltage decreases.
The sensor is located at the top left of the engine in the fuel injection pump supply tube, forward of the secondary fuel filter. The PCM uses the fuel pressure and temperature sensor inputs to command the correct fuel injector timing, the pulse width, and the correct injection control pressure for correct fuel delivery at all speed and load conditions.
Typical Fuel Pressure And Temperature Sensor