Onan 3 fault code — Generator
Applies to: QG 2800/2800 EVAP KV Spec E-M, QG 2500 LP KV legacy models
What 3 means
The Cummins Onan QG 2800 KV operator manual says three blinks indicate a service fault and the manual directs owners to press Stop once for the two-digit second-level shutdown code.
Owner-safe checks
- Press Stop once to read the second-level blink code if the manual procedure is available.
- Record both blink sequences before calling service.
Service-only work
- Internal generator electrical, fuel, engine, sensor, controller, and output-voltage diagnosis belongs to Cummins service or a qualified generator technician.
Safety boundary
Generators can produce carbon monoxide, moving-part hazards, fuel hazards, and lethal voltage. Shut the generator down and do not open energized compartments unless qualified.
Official sources
- Cummins Onan RV Generator Manuals
- Cummins Onan QG 2800/2800 EVAP KV Spec E-M Operator Manual 981-0153