Diagnosis of Electric Control Unit Failure of Volvo Diesel Genset

How to judge electric control unit failure of Volvo Diesel generator set? Dingbo Power generator manufacturer shares with you.

1. No matter whether diesel generator is running or not, the ECU, sensor and actuator must not be disconnected as long as the ignition switch is on. Due to the self induction of any coil, a high instantaneous voltage will be generated, causing serious damage to the ECU and sensor. The electrical devices that cannot be disconnected are as follows: any cable of the battery, prom of the computer, wire of any computer, etc.

2. Do not unplug the wire plug (connector) of any sensor when the diesel generator is running or in "on" gear, which will cause artificial fault code (one kind of false code) in ECU and affect the maintenance personnel to correctly judge and eliminate the fault.

3. When disassembling the high-pressure oil circuit, the pressure of the fuel system shall be relieved first. Pay attention to fire prevention when overhauling the oil circuit system.

4. When arc welding the diesel generator equipped with electronic control system, disconnect the power supply line of ECU to avoid damage to ECU caused by high voltage during arc welding; When repairing the diesel generator near the ECU or sensor, pay attention to protect these electronic components. When installing or removing the ECU, the operator should ground himself first to avoid static electricity on the body damaging the circuit of the ECU.

5. After removing the negative grounding wire of battery, all fault information (codes) stored in ECU will be cleared. Therefore, if necessary, read the fault information in the computer before removing the negative grounding wire of diesel generator battery.

6. When removing and installing the diesel generator battery, the ignition switch and other electrical equipment switches must be in the off position. Remember that the power supply system used by the electronically controlled diesel generator is negative grounding. The positive and negative poles of the battery shall not be connected reversely.

7. The diesel generator should not be installed with a radio station with a power of 8W. When it must be installed, the antenna should be as far away from the ECU as possible, otherwise the circuits and components in the ECU will be damaged.

8. When overhauling the electronic control system of diesel generator, avoid damage to the electronic control system due to overload. In the electronic control system of diesel generator, the working current of ECU and sensor is usually relatively small. Therefore, the load capacity of corresponding circuit components is also relatively small.

During the fault inspection, if the detection tool with small input impedance is used, the components may be overloaded and damaged due to the use of the detection tool. Therefore, pay attention to the following three points:

a. The test lamp cannot be used to check the sensor part and ECU of the diesel generator electronic control system (including the terminal).

b. Unless otherwise specified in the test procedures of some diesel generators, generally, the resistance of the electronic control system cannot be checked with a pointer multimeter, but a high impedance digital multimeter or a special detection instrument for the electronic control system should be used.

c. on the diesel generator equipment equipped with electronic control system, it is forbidden to check the circuit with grounding fire test or wire removal fire scratch.

9. Remember not to flush the computer control unit and other electronic devices of diesel generating set with water, and pay attention to the protection of the computer control system to avoid the abnormal operation of ECU circuit board, electronic components, integrated circuit and sensor caused by moisture.

Generally, do not open the ECU cover plate of the diesel generator, because most of the faults of the electronically controlled diesel generator are external equipment faults, and ECU faults are relatively few. Even if the ECU is faulty, it should be tested and repaired by professionals.

10. When removing the wire connector, pay special attention to loosen the locking spring (snap ring) of the diesel generator or press the latch, as shown in Figure 1-1 (a); When installing the wire connector, pay attention to plug it to the bottom and lock the lock (lock card).

11. When checking the connector with a multimeter, carefully remove the waterproof sleeve for the waterproof conductor connector of diesel generator; When checking the continuity, do not use too much force on the diesel generator terminal when the multimeter measuring pen is inserted.