Generator controller displays E19 and logs 'Coolant Level Low' or 'Coolant Level Switch Open'.

Safety first: Do not open the radiator cap on a hot engine. Allow the generator to cool completely.

• Check coolant level: Inspect the expansion tank and radiator (when cool). Top up with the correct coolant mixture to the specified level.
• Inspect for leaks: Look for dried coolant residue around hose joints, water pump, and radiator core. Repair or replace leaking components.
• Bleed air: If the system was recently serviced, bleed air from high points using bleed screws or by running the engine with the radiator cap off (if allowed by Kubota) until bubbles stop.
• Test level switch: Remove the coolant level switch from the radiator or tank and test continuity while moving the float. Replace if it does not change state correctly.
• Wiring check: Inspect the harness from the level switch to the controller for damage or corrosion at connectors.