RV Atlas

Onan ยท 32 codes

Cummins Onan QG gasoline generator fault codes (HGJAA, HGJAB, HGJBB)

Every fault code, display message, and status light listed in Onan's manuals and support pages for HGJAA / HGJAB / HGJAC and HGJBB operator manuals; HGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals; HGJAA / HGJAB / HGJAC Spec A-E. Select a code for what it means, what you can safely check, and when to call a technician.

Confirm your model

Codes are model-specific. Match the model number on the appliance data label to one of these before using the table:

HGJBB Spec A-B, HGJAA Spec J-K, HGJAB Spec J-L, QG RV generator, HGJAA Spec A-E, HGJAB Spec A-E, HGJAC Spec A-D, QG 5500/7000 EFI

Where to look and what to record

  • generator model/spec letter
  • hour meter
  • fault blink count
  • loads running when the shutdown occurred
  • oil level and oil type noted after shutdown

Code table

CodeWhat the manufacturer saysListed for
2Low Oil PressureHGJAA / HGJAB / HGJAC and HGJBB operator manuals
3Service CheckHGJAA / HGJAB / HGJAC and HGJBB operator manuals
4Over CrankHGJAA / HGJAB / HGJAC and HGJBB operator manuals
12Over VoltageHGJAA / HGJAB / HGJAC and HGJBB operator manuals
13Under VoltageHGJAA / HGJAB / HGJAC and HGJBB operator manuals
14Over FrequencyHGJAA / HGJAB / HGJAC and HGJBB operator manuals
15Under FrequencyHGJAA / HGJAB / HGJAC and HGJBB operator manuals
19Governor ActuatorHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
22Governor Actuator OverloadHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
23Low Oil Pressure Cutoff SwitchHGJAA / HGJAB / HGJAC Spec A-E
27Voltage SenseHGJAA / HGJAB / HGJAC and HGJBB operator manuals
29High Battery VoltageHGJAA / HGJAB / HGJAC and HGJBB operator manuals
31Over SpeedHGJAA / HGJAB / HGJAC and HGJBB operator manuals
32Low Cranking SpeedHGJAA / HGJAB / HGJAC and HGJBB operator manuals
35Control Card FailureHGJAA / HGJAB / HGJAC and HGJBB operator manuals
36Engine StoppedHGJAA / HGJAB / HGJAC and HGJBB operator manuals
37Invalid Generator Set ConfigurationHGJAA / HGJAB / HGJAC and HGJBB operator manuals
38Over Current (Field Overload)HGJAA / HGJAB / HGJAC and HGJBB operator manuals
41Generator RotorHGJAA / HGJAB / HGJAC and HGJBB operator manuals
42ProcessorHGJAA / HGJAB / HGJAC and HGJBB operator manuals
43ProcessorHGJAA / HGJAB / HGJAC and HGJBB operator manuals
45Speed SenseHGJAA / HGJAB / HGJAC and HGJBB operator manuals
47IgnitionHGJAA / HGJAB / HGJAC and HGJBB operator manuals
48Generator Field SenseHGJAA / HGJAB / HGJAC and HGJBB operator manuals
51ProcessorHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
52Fuel InjectorHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
54MAT SenderHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
56MAP SenderHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
57Over PrimeHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
58Exhaust Gas Temperature ShutdownHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
81Exhaust Gas Temperature Sensor OpenHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals
82Exhaust Gas Temperature Sensor ShortedHGJAA / HGJAB / HGJAC (QG 5500/7000 EFI) operator manuals

Generators can produce carbon monoxide, moving-part hazards, fuel hazards, and lethal voltage. Shut the generator down and do not open energized compartments unless qualified.

Troubleshooting guides

Official manuals and support pages

OnanCummins Onan RV Generator ManualsOnanCummins Onan Generator Set for RV Operator Manual A031C171OnanCummins Onan Generator Set for RV Operator Manual A035D009OnanCummins Onan RV Generator Set HGJAA/HGJAB/HGJAC Spec A-E Operator Manual 983-0101