Troubleshooting guide
Onan generator no-start cranking delay or overcrank
Cummins Onan quick-start and service support distinguish normal diesel glow-plug preheat, short crank attempts, and cool-down time from repeated no-start or overcrank conditions that need generator service.
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
- Use the normal start switch and allow diesel models up to 30 seconds for preheat before expecting cranking.
- Keep each start attempt under 20 seconds and wait at least 2 minutes between attempts.
- If the RV ran out of fuel, use the generator's normal prime procedure before one retry.
- Record fuel level, oil level, battery state, model/spec, and fault flashes, then call Cummins Onan or qualified generator service if it still will not start.
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