Cummins/Onan K450 troubleshooting: 8 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan K450 — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Remedy |
|---|---|---|
| OV | Output voltage | Set the switch to the desired AC or DC position |
| 3 ~ 6V | Only slight output voltage is delivered (3 ~ 6V) | Repair or replace. |
| Symptom | Cause | Remedy |
|---|---|---|
| Pilot lamp does not light and output voltage is OV | Faulty contact of receptacles or disconnected wiring inside of control box | Repair or replace |
| Output voltage is not delivered | Disconnected wiring | Repair or replace stator coil, demagnetization of permanent magnet, clean brush contact and slip ring, repair or replace brush, or repair or replace sub coil |
| Only slight output voltage is delivered (3 ~ 6V) | Worn brush or faulty contact surface of slip ring | Clean brush contact and slip ring, or replace brush |
| Rated output voltage is not available | Abnormal load circuit, blown circuit breaker (S.T.D., voltage 10%) | Remove abnormality in load circuit and replace fuse |
| Fluctuation of engine revolution is abnormal | Disconnected or punctured AVR capacitor, faulty brush contact, excessive initial current, low engine output, faulty engine governor | Replace capacitor, check for wear, wear amount, and contamination of contacting surface of brush and clean if necessary, repair or replace |
| Output voltage is more than S.T.D. voltage by 30% | Defective AVR | Replace |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Faulty contact of receptacles or disconnected wiring inside of control box. See the table for the matching fixes.
Documented causes: Disconnected wiring. See the table for the matching fixes.
Documented causes: Worn brush or faulty contact surface of slip ring. See the table for the matching fixes.