Generator shuts down; controller shows Fault Code 415 – Overspeed

Safety first: Overspeed can cause catastrophic mechanical failure. Do not repeatedly restart until the cause is identified. Disable automatic start.

• Check speed sensor: Locate the Cummins engine speed (magnetic pickup) sensor near the flywheel or crankshaft. Inspect for metal debris on the tip and clean gently. Check the connector and harness for damage.
• Inspect fuel actuator: On electronic engines, ensure the fuel control actuator or throttle body linkage moves freely and is not sticking. Do not force components; binding may require replacement.
• Controller settings: Verify that no unauthorized changes have been made to rated speed or frequency settings in the Cummins controller. Only qualified personnel should adjust governor parameters.
• Reset and test: After basic checks, clear the fault and perform a controlled start while monitoring engine speed and frequency. If overspeed recurs, stop immediately and contact a Cummins service provider.