00-040

UnclassifiedSpeed

What This Code Means

Engine runs rough; Engine misfires; Engine surges; Engine will not shut off; Excessive vibration; Engine will not crank or cranks slowly; Engine cranks but will not start; Engine run indicator not working

Possible Causes

  • Faulty fuel filter
  • Faulty fuel pump
  • Faulty carburetor choke
  • Faulty carburetor
  • Faulty spark plug wires
  • Faulty ignition coil
  • Faulty engine electrical ground
  • Faulty fuel supply
  • Plugged idle jet
  • Incorrect governor adjustment
  • Faulty intake manifold gaskets
  • Faulty ignition switch
  • Incorrect voltage at the ignition coil
  • Faulty pulleys
  • Faulty belts
  • Faulty couplings
  • Faulty air filter
  • Faulty control board
  • Faulty start solenoid
  • Loose or faulty connections on PCB assembly

Suggested Actions

  1. 1Check fuel filter
  2. 2Check fuel pump
  3. 3Check carburetor choke
  4. 4Check carburetor
  5. 5Check spark plug wires
  6. 6Check ignition coil
  7. 7Check engine electrical ground
  8. 8Check fuel supply
  9. 9Check for plugged idle jet
  10. 10Check governor adjustment
  11. 11Check intake manifold gaskets
  12. 12Check ignition switch
  13. 13Check voltage at the ignition coil
  14. 14Check pulleys
  15. 15Check belts
  16. 16Check couplings
  17. 17Check air filter
  18. 18Troubleshoot start solenoid
  19. 19Troubleshoot connections on PCB assembly
  20. 20Check fuel lines

ASK RUDY ABOUT THIS FAULT

Get a diagnosis walkthrough for 00-040 on your specific Onan unit — cited to the OEM manual, not a forum guess.

TRY IT FREE