Onan & Cummins Built-In Gensets: No-Start Diagnostics
WORK THROUGH THIS BEFORE ASSUMING THE GENSET IS DEAD
Owner guide
Onan, Cummins & Honda Generator Troubleshooting & Service Guide
Manufacturer-specific fault codes, no-start diagnostics, and service intervals for the generators most RVers actually own — built-in Cummins Onan gensets and portable Honda inverter generators. Onan & Cummins Built-In Ge...
Active corridor: Montana · Wyoming · Idaho · Washington — case-by-case beyond.
Field notes
Manufacturer-specific fault codes, no-start diagnostics, and service intervals for the generators most RVers actually own — built-in Cummins Onan gensets and portable Honda inverter generators. Onan & Cummins Built-In Gensets Onan Fault Code Reference Onan Service Intervals Honda Portable Generators
Onan Fault Code Reference & How to Read Them
Most Onan/Cummins RV generator control panels report faults through a flashing LED rather than a text screen. Press and hold the Stop button for about 5 seconds — the LED flashes the last fault code in a long-short pa...
Onan/Cummins Service Intervals
MISSED SERVICE IS THE #1 CAUSE OF GENSET FAILURES WE SEE
Honda Portable Generators (EU2200i / EU3000i)
THE MOST COMMON PORTABLE FOR BOONDOCKERS & TOWABLE OWNERS
Stuck on a Fault Code, or Want Us to Just Handle It?
If you want a second opinion before you start pulling panels, we offer a paid remote diagnostic call — walk through symptoms and codes with Matt directly over phone or video. If you’d rather have a tech on-site, we co...
Owner checklist
- Fuel level above 1/4 tank — many gas-genset no-starts on a “full” RV are really a fuel pickup tube that sits above the actual fuel line
- Engine oil level — low oil trips a safety cutoff and will prevent the unit from cranking or running at all
- Start battery voltage — slow cranking or no cranking after storage is almost always a weak or disconnected battery
- Old or contaminated fuel — gas that’s sat unused for months gums up the carburetor and fuel filter
- Automatic transfer switch and control board connections — a loose harness connector reads as “no start” even with a healthy engine
Related: All guides · Book a Service · Pricing
Pricing teaser
Trip fee $75 within 30 miles, then $1.50/mi. Labor ~$150/hr (1-hour minimum, billed in 30-minute increments). Diagnostic $150 applied toward repair if you proceed.
Active corridor: Montana · Wyoming · Idaho · Washington — case-by-case beyond. Credentials (text): Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified.