Onan 15 fault code — Generator
Applies to: QG 4000/3600 LP KY Spec J-N, QG 4000/3600 LP KY Spec P-R
What 15 means
The Cummins Onan QG 4000/3600 LP KY operator manuals list Code 15 as Under Frequency.
Owner-safe checks
- Reduce connected loads, especially air conditioners and battery chargers.
- Record whether the fault clears with fewer loads.
Service-only work
- Internal generator electrical output, inverter, controller, sensors, fuel system, ignition, AC circuit, and engine diagnosis belongs to Cummins service or a qualified generator technician.
Safety boundary
Generators can produce carbon monoxide, hot surfaces, fuel hazards, moving-part 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 4000/3600 LP KY Spec J-N Operator Manual 981-0159
- Cummins Onan QG 4000/3600 LP KY Spec P-R Operator Manual A041D131