The maintenance team replaced the aging sealing ring of the 0R-3190 injector connector, tightened the connector, and cleaned the oil stains on the wiring harness. At the same time, the damaged ECU was repaired. After maintenance, the short circuit fault was eliminated, and the truck resumed normal operation. The maintenance experts reminded that the connector of Caterpillar 0R-3190 injectors should be checked regularly to avoid oil leakage and short circuit of the electrical system.