The maintenance technicians checked the wiring harness of the 0R-3190 injectors and found that the wiring harness was老化 and cracked, and the connection between the harness and the injector plug was loose, resulting in poor contact and unstable signal transmission. When the engine was running, the ECU could not accurately control the injection time and injection volume of the injectors, leading to abnormal injection. In addition, the mining vehicles often work in harsh environments such as dust and vibration, which also accelerates the aging and damage of the wiring harness.