Cummins/Onan D402051MX02 Engine

How to read your Cummins/Onan engine serial & model number →

• Voltage regulator may require adjustment or is faulty
  Cause: Voltage, the voltage regulator may require adjustment or is faulty
  Fix: Refer to Tests and Adjustments section for adjustments, replace if faulty.
• Shutdown was due to over/under frequency
  Cause: If shutdown was due to over/under frequency, the engine governor may require adjustment or is faulty
  Fix: Refer to Tests and Adjustments section for adjustments, replace if faulty.
• Run RUN
• Overvoltage Monitor ES-1859-1
  Fix: Shut down the output device and trip an optional circuit breaker
• Overload Detector ES-1852
  Fix: Shut down the output device
• No fault lamp lit
  Cause: Possible defective ECM Check fuses F4 and F2 of ECM board A11.
  Fix: Perform restart and check for B+ voltage in at TB1-9 and voltage out at TB1-10 to fuel solenoid. If there is voitage out at TB1-10, check fuel supply solenoid, shutoff valves, etc. If there is no voltage out at TB1-10, ECM board A11 is defective. Replace.
• K5 - Fault 1 K5 - Fault 1
• K4 - Fault 2 K4 - Fault 2
• K19 - PLOP K19
• K17 - PHET K17
• K13 - HET K13
• Fault 2 FAULT 2
• Fault 1 FAULT 1
• Exciter field breaker trips (if equipped)
  Cause: Does AC output voltage build up to 150% or more of rated voltage before breaker trips? No; Check diodes in rotor assembly. Replace if bad.
  Fix: Check Voltage Regulator adjustments and connections. Check generator stator leads for proper, secure connection. Refer to appropriate electrical schematic. Check exciter rotor winding. Replace if bad. Check generator rotor field winding. Replace if bad. Check generator stator windings. Replace if bad. Do not replace Voltage Regulator Replace Voltage Regulator VR21. ACAUTION VR27 until external trouble has been corrected to avoid possible damage to new regulator board.
• AC output voltage too high or low
  Cause: Is engine running at correct rpm? No; Are generator output connections correct and secure? Yes; Does adjustment of Voltage Adjust control R21 (if equipped) result in correct output voltage? No; Check Voltage Regulator Adjustment. Check ok? No; Check condition of rotating diodes.
  Fix: Visually inspect for loose connections, faulty diodes, etc. Check ok? Yes; Do not replace Voitage Regulator Replace Voltage Regulator VR21. ACAUTION VR21 until external trouble has been corrected to avoid possible damage to new regulator board.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan D402051MX02.