What is the fuel common rail pressure sensor? How to overhaul? - SINOTRUK (HOWO) LIMITED
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What is the fuel common rail pressure sensor? How to overhaul?

The common rail pressure sensor (CRPS) is a pressure sensitive effect sensor with three terminals (as shown), and the common rail pressure sensor has three terminals, and the terminal is a wire line, and the No. 2 terminal is a signal output line.

The No. 3 is the power cord (5V). The main job is to detect the size of the hydraulic pressure in the high-voltage common rail pipe in real time, transmitting the signal to the ECU, ECU adjusts the amount of oil supply according to signal data

If the common rail pressure sensor is damaged, most of the cases are damaged due to the failure in the oil-circuit system in addition to the failure of the oil-circuit system. After the failure code provided by the vehicle is fixed, the detection of the rail sensor is performed. The detection method is as follows:

pressure sensor

1, external line check

The resistance unit of the multimeter is measured by the resistance value of the 1 terminal and the No. 2 terminal, the 2nd terminal, the terminal, and the terminals 3 terminals and the terminals of the terminal, and the exterior lines are short-circuited and broken.

2, sensor voltage value measurement

Turn off the ignition switch, unplug the common rail pressure sensor plug, turn on the ignition switch, measure the voltage between the sensor side plug 3 and the ribbon should be 5V, the voltage between the 2nd terminal and the collision should be about 0.5V, 1 The voltage between the terminal and the collision should be 0V.

Under normal circumstances, the voltage value of the 2nd end should increase with the throttle, otherwise it can be determined that the sensor fault signal output is not normal.

3, data stream detection

The data stream of the engine oil supply system is read with a dedicated diagnostic device, and the idle speed state is detected, and the oil pressure change is increased as the throttle, and the output voltage change of the rail pressure sensor is determined.


(1) When the diesel coolant temperature reaches 80 ° C, when the idle operation is operated, the “rail pressure sensor output voltage” should be around 1V, the fuel system rail pressure and the rail pressure set value are about 25.00 MPa. The rail pressure set value is very close to the fuel system track.


(2) When gradually stepped on the accelerator, when the diesel engine speed is improved, the rail pressure system data value gradually increases, the fuel system rail pressure, the rail pressure set value, the actual rail pressure maximum, etc. The maximum value is 145.00MPa, the rail sensor output voltage The maximum is 4.5V.

4, common fault phenomenon

When the common rail pressure sensor fails (if unplugged down), the diesel engine may not start, the engine is shaking after starting, the idle speed is unstable, accelerates a lot of black smoke, and accelerates weakness. Different models use different engine control strategies. Specific faults are different from models.

(1) When the common rail pressure sensor fails, the diesel engine cannot start.


(2) When the common rail pressure sensor is invalid, the diesel engine can start and operate normally but the engine is twisted.

(3) Frequently fault code when the common rail pressure sensor fails (lost),
1 The engine cannot be started and running: P0192, P0193;
2 signal drift, engine smathes: P1912, P1192, P1193.

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