Generator shuts down shortly after starting and displays E03 on the controller.

Safety: Allow the engine to cool. Turn OFF the generator, isolate battery negative, and prevent automatic start.

• Check oil level: Use the engine dipstick to verify oil level. Top up with the manufacturer-specified oil grade if low. Do not overfill.
• Inspect for leaks: Look around the oil filter, sump, and oil cooler connections for visible oil leaks. Repair or tighten fittings as needed.
• Test oil pressure switch: Locate the oil pressure switch on the engine block (refer to Himoinsa engine layout). Disconnect the connector and test the switch with a multimeter according to the engine manual (normally closed or open type). Replace if defective.
• Check wiring to controller: Inspect the harness from the oil pressure switch to the Himoinsa controller for damage, loose pins, or corrosion at connectors.
• Verify actual oil pressure (advanced): If tools are available, install a mechanical oil pressure gauge in place of the switch and crank/start the engine briefly to confirm real oil pressure. If pressure is low, do not run the engine; contact a diesel specialist to inspect the oil pump and internal engine components.