Cummins/Onan Not explicitly stated in the document troubleshooting: 18 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan Not explicitly stated in the document — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Symptom | Cause | Remedy |
|---|---|---|
| FAILS TO CRANK | 1. Low battery. 2. Bad battery connection. 3. Blown fuse. | 1. Check battery fluid level. 2. Clean & tighten all battery & cable connections. 3. Replace fuse on control panel. |
| CRANKS SLOWLY | 1. Low battery. 2. Bad battery connection. 3. Incorrect oil viscosity. 4. Load connected. | 1. Check battery fluid level. 2. Clean & tighten all battery & cable connections. 3. Replace with recommended viscosity oil. 4. Disconnect load before starting. |
| CRANKS BUT WON’T START | 1. Fuel below generator pickup level in tank. 2. Fuel supply shutoff valve closed. 3. Carbon deposits on spark plug(s). 4. Low oil level. | 1. Add fuel. 2. Fully open fuel supply valve. 3. Remove spark plug(s) and replace. 4. Add oil. |
| EXHAUSTING BLACK SMOKE | 1. Dirty air filter. | Replace air filter. |
| UNIT RUNS THEN STOPS, OR STOPS WHEN DRIVING AROUND A CORNER | 1. Low fuel level. 2. Low oil level. 3. Excess oil. | 1. Add fuel. 2. Add oil. 3. Reduce engine oil level. |
| UNIT STARTS AND RUNS, THEN STOPS WHEN THE START SWITCH IS RELEASED | 1. Low fluid levels. | Check & bring all fluids up to the appropriate levels. |
| UNIT RUNS THEN SURGES | 1. Loose or worn spark plug leads. 2. Defective ignition coil, wiring, or control components. 3. Faulty spark plug. 4. Governor out of adjustment. 5. Combustion air pre-heat malfunction. 6. Carburetor icing. 7. Carburetor varnishing. | 1. Check spark plug leads at spark plug & ignition coil. 2. Contact an Onan Authorized RV Service & Parts Dealer. 3. Remove spark plug & clean or replace. 4. Contact an Onan Authorized RV Service & Parts Dealer. 5. Contact an Onan Authorized RV Service & Parts Dealer. 6. Move carburetor pre-heater to the winter position. 7. Try fuel system cleaner and contact dealer if no change. |
| CIRCUIT BREAKER TRIPS | 1. Overloaded circuit. | Turn-off some of the electrical load, and reset the circuit breaker. |
| Smoke and rough operation | Oil in the cylinders has not been burned off yet. | Continue running the generator set until the oil in the cylinders is burned. |
| Generator set runs louder than usual, compartment has holes to the interior, or exhaust system has leaks | Do not operate the generator set and have the exhaust system repaired as soon as possible. See your Onan service center. | |
| UNIT RUNS THEN STOPS | 1. Run the generator set at 50 percent capacity for one hour. 2. Turn off the fuel supply and remove the air filter. As the generator set runs out of fuel, squirt defogger into the carburetor intake and reassemble air filter. 3. Shut the generator set off. Remove the spark plugs. Pour one tablespoon (about 30 ml) of standard engine oil into the spark plug holes. Crank the engine for about 10 seconds. Replace the spark | |
| The two-digit code consists of 1, 2, 3, 4 or 5 blinks, a brief pause, and then 1 to 9 blinks. | Cranking time exceeded 35 seconds (indicated by four blinks). | |
| The fault code stops blinking after five minutes. | Press Stop three times within three seconds to restore fault code blinking. | |
| Dizziness | IF YOU EXPERIENCE ANY OF THESE SYMPTOMS, GET INTO FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Vomiting | IF YOU EXPERIENCE ANY OF THESE SYMPTOMS, GET INTO FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Weakness and Sleepiness | IF YOU EXPERIENCE ANY OF THESE SYMPTOMS, GET INTO FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Inability to Think Coherently | IF YOU EXPERIENCE ANY OF THESE SYMPTOMS, GET INTO FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Engine does not start | Spark plug may be fouled by the fogger | Clean or replace the spark plug |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: 1. Low battery. 2. Bad battery connection. 3. Blown fuse.. See the table for the matching fixes.
Documented causes: 1. Low battery. 2. Bad battery connection. 3. Incorrect oil viscosity. 4. Load connected.. See the table for the matching fixes.
Documented causes: 1. Fuel below generator pickup level in tank. 2. Fuel supply shutoff valve closed. 3. Carbon deposits on spark plug(s). 4. Low oil level.. See the table for the matching fixes.