Controller shows E12 and prevents starting; often appears after a long storage period.

Safety first: Turn OFF the generator and disconnect the battery negative cable. Work in a well‑ventilated area away from ignition sources when handling fuel.

• Check actual fuel level: Open the fuel tank access and visually confirm fuel level. If low or empty, fill with the correct fuel type specified by WEN (diesel, gasoline, or LP tank level for certain models).
• Inspect fuel level sender: Locate the fuel level sender on the top of the tank. Check the electrical connector for corrosion or loose pins. Clean and reseat the connector.
• Test sender resistance: Disconnect the sender and measure resistance while manually moving the float arm (if accessible). Resistance should change smoothly. If it is open, shorted, or erratic, replace the fuel level sender.
• Check wiring to controller: Trace the sender wires to the controller harness. Repair any damaged sections and ensure proper grounding.
• Reset and test: After confirming fuel level and sensor operation, reconnect the battery, clear E12, and attempt a start. If the code persists, the fuel level input circuit on the controller may be faulty.