Troubleshooting guide
Onan generator fuel, oil, and maintenance checks before starting
Cummins Onan quick-start, service FAQ, and handbook maintenance guidance emphasize correct fuel, engine oil level, 150 hours or yearly oil service, air cleaner attention in dusty conditions, and regular exercise before no-start troubleshooting.
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
- Confirm fuel is available for the generator and record whether the RV recently ran low.
- Check engine oil level only by the normal dipstick procedure for the installed model.
- Compare the hour meter and last service date against the 150 hours or yearly oil-service interval.
- Record dusty travel, air cleaner condition, and exercise history before calling Cummins Onan or qualified generator service.
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