Controller shows E09 and the generator will not transfer load even though it is running.

Safety first: Isolate the generator from the building by opening the transfer switch. Turn OFF nonessential loads. Use a frequency meter or multimeter with Hz function for accurate checks.

• Measure frequency: With the generator running no‑load in manual mode, measure output frequency at the generator lugs. It should be close to 60 Hz (or your local standard). If it is significantly high or low, engine speed must be corrected.
• Inspect governor linkage: Shut down the engine and check the governor arm, springs, and throttle linkage for binding or misadjustment. Repair or replace worn linkage components.
• Adjust engine speed: On many WEN engines, a governor adjustment screw sets no‑load RPM. Following the WEN service manual, adjust the screw in small increments while monitoring frequency until it stabilizes at the correct value. Do not overspeed the engine.
• Check fuel stability: Ensure gas pressure (NG/LP) is within WEN specifications under load. Fluctuating pressure can cause RPM and frequency swings. Have your gas supplier verify pressure if needed.
• Controller/AVR check: If mechanical speed is stable but the controller still reports E09, the frequency sensing circuit on the control board or AVR may be defective. Inspect wiring from the alternator sensing leads to the controller and replace the control board or AVR if confirmed faulty.