Controller displays “Low Oil Pressure” and shuts down the generator shortly after start or prevents start.

Safety first: Turn generator to OFF, open the main AC breaker, and allow the engine to cool completely. Do not run the engine with suspected low oil pressure.

Steps:

• Check oil level: Remove the dipstick on the Eaton standby generator engine and verify oil level is between the FULL and ADD marks. Top off with the manufacturer-specified oil grade if low.
• Inspect for leaks: Look around the oil filter, drain plug, and crankcase gasket for signs of oil leakage. Tighten the oil filter and drain plug if seeping; replace gaskets or components if leaking heavily.
• Inspect oil pressure switch: Locate the oil pressure switch on the engine block. Check the connector for corrosion, loose fit, or damaged wires. Clean and reseat the connector.
• Test switch (basic): With the engine off, disconnect the oil pressure switch and check continuity per Eaton/engine manual. Many switches are normally closed to ground with no pressure. Replace if readings are out of spec.
• Reset and test: Clear the alarm and attempt a manual start. If the unit still shuts down immediately with a verified correct oil level, do not continue to run it—have oil pressure tested mechanically by a technician to rule out internal engine damage.