Cummins/Onan HGJAA troubleshooting: 37 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan HGJAA — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning |
|---|---|
| 2 | Low Oil Pressure Fault |
| 3 | Service Check Fault |
| 4 | Overcrank |
| 12 | Overvoltage |
| 13 | Undervoltage |
| 14 | Overfrequency |
| 15 | Underfrequency |
| 17 | Fuel Pump Fault |
| 19 | Governor Actuator (EFI Only) |
| 22 | Governor Actuator Overload (EFI Only) |
| 23 | Oil Pressure Switch Fault |
| 27 | Voltage Sense Lost |
| 29 | High Battery Voltage |
| 31 | Overspeed Fault |
| 32 | Low Cranking Speed Sense |
| 33 | Fault Code 3 - Fault Code 33 |
| 35 | Control Card Failure |
| 36 | Generator Set Stopped Without Fault Condition - Fault Code 36 |
| 37 | Invalid Set Configuration |
| 38 | Field Overload (Overvoltage) |
| 41 | Alternator Rotor Fault |
| 42 | Processor Fault - Fault Code 42 |
| 43 | Processor Fault - Fault Code 43 |
| 45 | Speed Sense Fault |
| 47 | Ignition Fault |
| 48 | Field Sense Fault |
| 51 | Processor Failure - Fault Code 51 |
| 52 | Fuel Injector Fault (EFI Only) |
| 54 | MAT Sensor Fault (EFI Only) |
| 56 | MAP Sensor Fault (EFI Only) |
| 57 | Overprime Fault |
| 36 | Generator Set Stopped Without Fault Condition |
| 42 | Processor Fault |
| 51 | Processor Failure |
| 58 | Exhaust Gas Temperature Shutdown |
| 81 | Exhaust Gas Temperature Sensor Open |
| 82 | Exhaust Gas Temperature Sensor Shorted |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.