In the TICS fuel injection pump electronic control system, ECU (engine control unit) has a fault self-diagnosis function, which can detect the working conditions of each part of the control system. When the ECU detects the fault signals from the sensors and actuators, it immediately lights up the “CHECKENGINE” (check engine, also called fault self-diagnostic lamp) warning light, and stores the fault information in the memory in the form of a fault code.
The following focuses on how to use the fault code to diagnose and troubleshoot.
1. Retrieve diagnostic trouble code (DTC)
Retrieving fault codes to diagnose electronic control system faults is a very important basic method for repairing modern construction machinery. Usually, the code switch (fault self-diagnosis switch) will flash the “CHECKENGINE” warning light to read the fault code. The fault code retrieval method is as follows:
(1) Check whether the memory connector is closed.
(2) Turn off the start switch and turn it on again, but do not start the engine.
(3) Connect the memory code switch. The memory code switch is the blue connector on the lower left side of the dashboard,
(4) The “CHECK ENGINE” fault light on the dashboard flashes, and the fault codes are displayed in the order of the faults.
2. Read diagnostic trouble code
Three different flashing numbers indicate the code starting from three digits, and two different flashing numbers indicate the code starting from two digits. The flashing code word can be used to identify the diagnosis trouble code. When there are multiple diagnosis trouble codes, after one diagnosis trouble code is repeated 3 times, it will go to the next diagnosis trouble code. The diagnostic fault codes of the 6HK1-TC engine are shown in the attached table.
The backup control in the attached table is the safety insurance or “home” function provided by the TICS fuel injection pump electronic control system. When the ECU detects a sensor or circuit failure, it will control the engine to enter the forced operation state according to the program and data originally set by the ECU Or downtime.
3. Clear diagnostic trouble code
According to the prompt of the fault code, after the fault is eliminated, although the “CHECKENGINE” warning light has been extinguished, the fault information is still stored in the memory of the ECU and cannot be automatically eliminated as the fault is eliminated. Therefore, after troubleshooting, the fault code stored in the memory should also be cleared to avoid being mixed with the newly generated fault information and causing difficulties for the next maintenance. The procedure for clearing fault codes is as follows:
(1) Check whether the memory connector is closed.
(2) Turn off the start switch, and then turn it on again.
(3) Connect the memory clear switch for 1s. The memory clear switch is the white connector on the lower left side of the dashboard,
(4) Disconnect the memory connector and clear the memory 0.5 s after disconnection.
(5) Turn off the start switch and turn it on again, and check whether the diagnostic trouble code is cleared. If it still exists, repeat the above steps (1) to (4).
4. Precautions for use and maintenance
(1) When jumping to start other vehicles or use other vehicles to bridge the machine, the ignition switch should be turned off before the jumper can be disassembled.
(2) After the fuel injection pump is installed, the fuel injection pump can be started after exhausting the air, otherwise the pre-stroke actuator may be easily burned out.
(3) When moving the pump, do not carry the wiring harness or electrical components to prevent damage.
(4) Do not open the computer cover during maintenance, because the computer cannot be repaired even if it is broken, and it is likely to damage the computer after opening.
(5) It is strictly forbidden to disconnect the battery from the circuit when the engine is running at high speed to prevent transient overvoltage from damaging the computer and sensors.
(6) When the engine electronic control system fails, the CHECKENGINE warning light (CHECKENGINE) lights up, and the ECU stores the fault information in the memory, so the battery cannot be disconnected from the circuit to prevent the fault stored in the computer The code and related data information are cleared. The battery can be disconnected from the circuit only after the fault code and related information are called out through the fault self-diagnosis system and the cause of the fault is diagnosed.
5. Fault diagnosis case
(1) The engine cannot be started
(2) The engine cannot be started
(3) The engine cannot be started
(4) When the engine speed is increased to about 2 000 r/min, the speed cannot be increased any more, the operation is weak and the action is slow, and a lot of black smoke is emitted.
(5) The engine is running weak, and a lot of black smoke is emitted
(6) Sometimes the engine stalls by itself
(7) The engine is running weak, and a lot of white smoke is emitted