During the use of the excavator, the high-pressure common rail may fail and give an alarm. If the excavator is equipped with ECU, the corresponding fault code will appear. Understanding the fault code can more effectively check and repair the excavator. This article will analyze several common codes in case of high-voltage common rail failure for reference only.
Detect the fuel pressure in the common rail, send the signal to ECU, send the driving signal to SCV valve through ECU, and adjust the fuel output from diesel pump to the common rail. When the pressure in the common rail reaches abnormal high pressure, open the valve to release the pressure. When the pressure rises to about 200MPa, the valve opens and the fuel returns to the oil tank. When the pressure drops to 50MPa, the valve is closed to maintain the pressure in the common rail. The high-pressure fuel distributed by the common rail is changed into a fine spray state, and the nozzle is directly injected into the combustion chamber.
The following is the common code analysis caused by high pressure common rail fault:
P0088、P0191、P0192、P0193
The above codes are common rail pressure abnormal alarm codes, which are abnormal pressure on common rail. The alarm collects the electrical signal of the pressure sensor. Therefore, the first possible problem is the connection of the line connector of the sensor itself, and check whether there are faults such as water ingress and looseness. Secondly, measure the voltage between the terminals on the ECU side of the corresponding harness and the voltage between the terminals on the sensor side. Moreover, the possible problem is the pressure control valve. If the valve core is jammed, it will cause an alarm of high or low pressure, and the fuel filling does not directly contact the alarm. There may be impurities stuck at that time. After restarting, it just flushes away the impurities and returns to normal. Please observe and use. If the alarm continues, the output may drop.
