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How to troubleshoot the electronic control unit ECU of the common rail diesel engine?

April 20, 2022
The diesel engine electronic control unit (ECU) is one of the most critical components of the generator set, which not only requires high system reliability, but also low cost. The electronically controlled common rail fuel system detects the actual operating state of the engine through various sensors, and through the calculation and processing of the engine electronic control unit, the fuel injection time, fuel injection pressure and fuel injection rate can be optimally controlled.
The failure of the electronic control unit (ECU) of the common rail diesel engine can easily cause the diesel engine to fail to start and stall. Common rail electronic control unit (ECU) common failure causes and solutions are as follows.
Fault type 1: The communication between the diagnostic instrument and the ECU fails, and the fault indicator and cold start lamp do not self-check after the ignition switch is turned on.
Cause analysis: ECU burns out
Solution: replace the ECU
Fault type 2: K line no voltage
Cause analysis: 1.89 terminal circuit problem.
Treatment method: check the 1.89 circuit
Remarks: Generally 24v
Fault type three: ECU terminals are bent or broken
Cause analysis: improper operation when unplugging the ECU plug
Treatment method: Straighten the terminal or replace the ECU
Fault type four: ECU is broken down by high current
Cause analysis: The circuit is short-circuited or the ECU plug is not unplugged during welding
Solution: replace the ECU
Note: Pay attention to the reliability of the ECU circuit, and pay attention to the protection of the ECU when welding.
Fault type five: ECU terminal short circuit
Cause Analysis: Entering Conductive Liquid
Treatment method: clean the liquid or replace the ECU
Remarks: The wiring harness adds a sealing ring and is waterproof