Atlas Copco controller shows E006 Low Fuel Level or Fuel Level Alarm, generator will not start in auto

Safety first: Work in a well‑ventilated area away from open flames. Use appropriate PPE when handling diesel fuel.

• Verify actual fuel level: Physically check the main fuel tank gauge or dipstick. If low, refill with the correct diesel grade and bleed the fuel system if required by the engine design.
• Inspect fuel level sensor: Locate the level sender on the tank (often a float‑type or resistive probe). Check for loose mounting, damaged float arms, or corrosion on terminals.
• Check wiring harness: Follow the fuel level sensor wires to the controller input. Repair any damaged insulation or loose connectors.
• Controller calibration: In the controller service menu, verify that the fuel level input type and scaling (e.g. 0–90 Ω, 4–20 mA) match the installed sensor. Recalibrate empty and full points if necessary.
• Test sensor: Disconnect the sensor and measure resistance or current while moving the float. Replace the sensor if readings are erratic or out of range.

After correcting the issue, clear the E006 alarm and test automatic start by simulating a mains failure.