Troubleshooting guide
Onan generator low battery or slow cranking
Cummins Onan quick-start and handbook guidance call for a charged starting battery around 600 Cold Cranking Amps, clean visible battery terminals, and service help when low cranking or repeated low-battery symptoms remain.
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
- Record battery monitor state before the start attempt.
- Confirm the installed starting battery is charged and appropriately rated for the generator.
- Look for loose or corroded visible battery terminals from normal safe access.
- Call qualified RV electrical or generator service if slow cranking, low-battery display messages, or repeated no-start symptoms remain.
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