Controller displays LOP and generator will not start or shuts down shortly after starting.

Safety first: Ensure the generator is OFF and cannot start automatically. Allow the engine to cool fully before checking oil.

• Check oil level: Remove the dipstick and verify oil is at the full mark. Top up with the Briggs & Stratton-recommended oil grade (often 5W-30 synthetic for standby units) if low. Do not overfill.
• Inspect for leaks: Look around the oil filter, drain plug, and crankcase gasket for fresh oil. Tighten the oil filter and drain plug if seeping. Repair any obvious leaks before running again.
• Test the oil pressure switch: Locate the oil pressure switch on the engine block. Inspect the connector for corrosion or broken wires. With the engine off, disconnect the switch and see if the LOP code changes to a different fault when attempting to start. A switch that is stuck open/closed may need replacement.
• Oil condition and viscosity: If the oil is very dirty or thick, perform a complete oil and filter change using the correct Briggs & Stratton oil and filter. Thick or degraded oil can cause low pressure when hot.
• Clear the code: After correcting the issue, set the controller to OFF for 30 seconds, then back to AUTO. Start in MANUAL and monitor for leaks and normal operation.