Identification and detection of capacitive intake manifold pressure sensor 1

1) Identification of capacitive intake manifold pressure sensor  diode

The sensor uses an alumina membrane and a base plate arranged close to each other to form a capacitor. By utilizing the property of the capacitor membrane changing due to the pressure difference between the upper and lower parts, a capacitance value signal proportional to the pressure is obtained, as shown in Figure 1. Connect the capacitor (i.e. pressure conversion element) to the oscillation circuit of the sensor hybrid integrated circuit, and the sensor generates a variable frequency signal. The frequency of its output signal is proportional to the pressure of the intake manifold and varies within the range of 80-120Hz. The output signal is sent to the electronic control unit, and the computer can sense the pressure of the intake manifold to calculate the basic fuel injection quantity of the engine.diode

(2) Detection of Ford Motor's Capacitive Intake Pressure Sensor

Figure 2 shows the connection circuit diagram between the capacitive intake pressure sensor used by Ford Motor Company and the computer. It can be seen from the diagram that the intake pressure sensor has three wires connected to the computer (ECU). The 26 terminal of the ECU provides 5V voltage to the intake pressure sensor; Terminal 46 is the signal circuit, which is grounded through the ECU; Terminal 45 is the output signal terminal of the intake pressure sensor. Ford vehicles are equipped with capacitive intake pressure sensors, and the detection method is as follows:diode