The following will introduce the function, working principle, fault phenomenon and diagnosis method of the rail pressure sensor. If you encounter rail pressure sensor failure in maintenance, you can try the following measurement methods.
The function of the fuel rail pressure sensor is to measure the real-time pressure of the fuel in the fuel rail with sufficient accuracy in a short time, convert the pressure signal into voltage signal, and transmit it to the ECU at the same time, so as to realize the control of the fuel injection accuracy and timing.
1、 Installation position
The rail pressure sensor is mounted on the fuel distributor line.
2、 How it works
The oil pressure acts on the metal diaphragm of the pressure sensor to deform the diaphragm, which is composed of four metal strain gauges
Wheatstone bridge, the deformation of the diaphragm causes the strain gauge resistance change, through the signal processing of the peripheral circuit, forming a line with the pressure
Voltage signal of sexual relationship.
3、 Fault phenomenon and judgment method
Common causes: improper use, such as the use of unsealed connectors, reverse high voltage and current, etc.
Maintenance precautions: after the engine stops running, it needs to wait at least 30s before maintenance operation; No operation is allowed when the engine is running; The unloading process of the sensor needs to be carried out slowly to balance the pressure inside and outside the oil rail.
Simple measurement method: remove the sensor, connect 5V voltage under normal temperature and pressure, and the pressure signal output is 0500 ± 0048v.
2: sensor signal
3. Signal power supply