Cummins/Onan C50 D6 troubleshooting: 20 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan C50 D6 — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning |
|---|---|
| Code 135 | Oil Pressure Sensor OOR - High |
| Code 141 | Oil Pressure Sensor OOR - Low |
| Code 143 | Engine Oil Pressure Low (Warning) |
| Code 144 | Engine Coolant Temperature OOR Low (Warning) |
| Code 145 | Engine Coolant Temperature OOR High (Warning) |
| Code 146 | Engine Coolant Temperature Above Normal (Warning) |
| Code 151 | Engine Coolant Temperature High (Shutdown) |
| Code 234 | Engine Speed High (Shutdown) |
| Code 359 | Engine Fail to Start |
| Code 415 | Engine Oil Pressure Low (Shutdown) |
| Code 441 | Low Battery Voltage |
| Code 442 | High Battery Voltage |
| Symptom | Remedy |
|---|---|
| Fuel contact with hot engine or exhaust | Do not permit any flame, cigarette, pilot light, spark, arcing equipment, or other ignition source near the generator set or fuel tank. Fuel lines must be adequately secured and free of leaks. Use an approved flexible line for fuel connection at the engine. Do not use copper piping on flexible lines as it will become brittle if continuously vibrated or repeatedly bent. Ensure all fuel supplies have a positive shutoff valve. |
| Batteries can explode | Do not dispose of the battery in a fire, because it is capable of exploding. Do not open or mutilate the battery. Do not charge frozen batteries. Batteries present the risk of high short circuit current when servicing the generator set: remove watches, rings, or other metal objects; use tools with insulated handles. |
| Exhaust gases are deadly | Provide an adequate exhaust system to properly expel discharged gases away from enclosed or sheltered areas, and areas where individuals are likely to congregate. Visually and audibly inspect the exhaust system daily for leaks per the maintenance schedule. Ensure that exhaust manifolds are secured and not warped. Do not use exhaust gases to heat a compartment. Make sure the unit is well ventilated. |
| Dizziness | IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Muscular Twitching | IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Vomiting | IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Weakness and Sleepiness | IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Inability to Think Coherently | IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.