Troubleshooting guide
Onan generator stopped and shows a fault code
Use this when an Onan/Cummins RV generator stops and flashes a numeric fault code.
Use this atlas to identify likely meaning and prepare for service. Shut off power, LP gas, fuel, or water when a listed appliance condition involves flame, gas smell, exhaust, generator shutdown, high temperature, moving jacks/slides, refrigerant, 120 VAC, control boards, repeated ignition failure, or a persistent lockout. Call the appliance maker, RV dealer, or a qualified RV technician for repair.
Owner-safe checklist
- Turn the generator off.
- Do not run in unsafe ventilation conditions.
- Record model/spec, hour meter, code, load, weather, and fuel state.
Code tables for these appliances
- Cummins Onan QG gasoline generators (HGJAA, HGJAB, HGJBB) 32 codes
- Cummins Onan QG 2800i / 2500i LP inverter generators 29 codes
- Cummins Onan QG 2800 KV generators 4 codes
- Cummins Onan QG 4000 / 3600 LP generators 19 codes
- Cummins Onan QG 7000i dual-fuel inverter generators 25 codes
- Cummins Onan Quiet Diesel 5000-12500 generators 23 codes
- Cummins Onan Quiet Diesel 3200 generators 14 codes
Related fault codes
- Onan generator code 12
- Onan generator code 13
- Onan generator code 14
- Onan generator code 15
- Onan generator code 19
- Onan generator code 2: Low Oil Pressure
- Onan generator code 22: Governor Actuator Overload
- Onan generator code 27
- Onan generator code 29
- Onan generator code 3: Service Check
- Onan generator code 31
- Onan generator code 32
- Onan generator code 35
- Onan generator code 36
- Onan generator code 37
- Onan generator code 38
- Onan generator code 4: Over Crank
- Onan generator code 41: Generator Rotor
- Onan generator code 42: Processor
- Onan generator code 43
- Onan generator code 45
- Onan generator code 47: Ignition
- Onan generator code 48: Generator Field Sense
- Onan generator code 51: Processor
Plus 34 more codes; browse by model from the appliance list.
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 Quick Start GuideOnanCummins Onan RV Generator Parts and Maintenance SupportOnanCummins Onan RV Generator Winterization Flyer 5410842OnanCummins Onan RV & Commercial Mobile Generator Accessory Catalog 6646901