Onan generator · 8 model lines
Onan generator code 15
Most Onan documentation lists 15 as “Under Frequency”. Some model lines word it differently or give it a different meaning: QG 2800i / 2500i LP (HGLAA Spec A-B) (“Output Under Frequency”).
Check your model first. The same code can mean different things on different models. Find the model number on the appliance's data label, then use the matching row below.
What code 15 means by model
What you can safely check
- Reduce connected loads, especially air conditioners and battery chargers.
- Record whether the generator recovers with fewer loads.
- Record whether the fault clears with fewer loads.
- Let the generator cool before another start attempt.
Stop and call a technician for
- Internal generator electrical output, inverter, controller, sensors, fuel system, ignition, AC circuit, and engine diagnosis belongs to Cummins service or a qualified generator technician.
- Electrical output, inverter, controller, stator, rotor, fuel injection, sensors, wiring, coolant-system service, fuel leaks, and generator compartment repairs belong to Cummins service or a qualified generator technician.
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.
Write this down before you call
- generator model/spec letter
- hour meter
- fault blink count
- loads running when the shutdown occurred
Full code tables for these models
Related troubleshooting guides
Official sources
OnanCummins Onan RV Generator ManualsOnanCummins Onan Generator Set for RV Operator Manual A031C171OnanCummins Onan Generator Set for RV Operator Manual A035D009OnanCummins Onan RV Generator Set HGJAA/HGJAB/HGJAC Spec A-E Operator Manual 983-0101OnanCummins Onan Quiet Diesel 10000/12500 HDKCA/HDKCB Operator Manual A043D713OnanCummins Onan Quiet Diesel 5000 HDKBA Operator Manual 0981-0166OnanCummins Onan Quiet Diesel 6000/7500/8000 HDKAH/HDKAJ/HDKAK Operator Manual A046L053OnanCummins Onan QG 4000/3600 LP KY Spec J-N Operator Manual 981-0159OnanCummins Onan QG 4000/3600 LP KY Spec P-R Operator Manual A041D131OnanCummins Onan QG 2800i/2500i LP HGLAA Spec A Operator Manual A062Y985OnanCummins Onan QG 2800i/2500i LP HGLAA Spec B Operator Manual A075S349OnanCummins Onan QG 7000i DF HGLCA Spec A Operator Manual A079E225OnanCummins Onan QG 4000/3600 LP KYD Spec A-C Operator Manual 981-0169