Generator shuts down; controller displays Fault Code 143 – Low Oil Pressure

Safety first: Allow the generator to cool completely. Hot oil and components can cause burns. Disable automatic start and lock out the transfer switch if you will be working near the engine.

• Check oil level: Use the engine dipstick to verify oil level. Top up with the correct grade and specification recommended by Cummins (see nameplate/manual). Do not overfill.
• Inspect for leaks: Look around the oil filter, oil pan gasket, crankshaft seals, and oil cooler lines for fresh oil. Tighten loose fittings and replace damaged hoses or gaskets.
• Oil filter and condition: If the oil is very dirty or past service interval, perform an oil and filter change using a genuine Cummins oil filter. This can restore proper flow and pressure.
• Check oil pressure sender: Locate the Cummins oil pressure sensor on the engine block. Inspect the connector for corrosion or loose pins. If possible, temporarily connect a mechanical oil pressure gauge to confirm actual pressure. Replace the sender if mechanical pressure is normal but the controller still reports low pressure.
• Reset and test: Clear the fault and run the generator while monitoring for abnormal noises (knocking, ticking) that could indicate internal wear. If low pressure persists with correct oil level, stop the unit and contact a Cummins service provider.