What does the Komatsu 200 alarm Lo3 mean?

[Samuel]

Komatsu 200 alarm L03 indicates an engine controller power supply failure or an engine control drive system circuit malfunction. Troubleshooting: The engine ECU can only function properly with a stable power supply and grounding. Avoid using low-quality fuel, as it can lead to poor engine combustion, excessive carbon buildup, piston ring sintering causing cylinder scoring. Additionally, inferior fuel accelerates wear on the fuel injection pump plunger pair, delivery valve pair, and fuel injector nozzles. The engine's power supply and grounding system includes: Engine ECU system voltage, engine ECU power circuit, engine output reference voltage, sensor grounding, and other components. When suspecting an engine ECU malfunction, never overlook checking the ECU's power supply and grounding.