Cummins/Onan DFEK troubleshooting: 16 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan DFEK — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Cause |
|---|---|---|
| 121 | SPEED SIGNAL LOST | Indicates that no magnetic pickup pulses were sensed for a Loss of Speed delay. If a magnetic pickup is disabled, this fault is not activated. |
| 135 | OIL PRESS SENSOR OOR HIGH | Indicates the oil pressure sensor output is out of range (OOR), high. |
| 141 | OIL PRESS SENSOR OOR LOW | Indicates the oil pressure sensor output is out of range (OOR), low. |
| 143 | PRE-LOW OIL PRESSURE | Indicates the engine oil pressure is approaching an unacceptable level. |
| 144 | COOLANT SENSOR OOR LOW | Indicates the coolant temperature sensor output is out of range (OOR), low. |
| 145 | COOLANT SENSOR OOR HIGH | Indicates the coolant temperature sensor output is out of range (OOR), high. |
| 146 | PRE-HIGH COOLANT TEMP | Indicates that the engine is operating near cooling system capacity. Increase in load or higher ambient temperature may cause High Coolant Temp (code 151) shutdown. |
| 151 | HIGH COOLANT TEMP | Indicates that the engine coolant temperature is above normal and has reached the Shutdown trip point. |
| 153 | INTAKE MANIFOLD TEMP OOR HIGH | Indicates that the intake manifold temperature sensor is out of range (OOR), high. |
| 154 | INTAKE MANIFOLD TEMP OOR LOW | Indicates that the intake manifold temperature sensor is out of range (OOR), low. |
| 155 | INTAKE MANIFOLD TEMP HIGH | Indicates that the intake manifold temperature sensor is above normal and has reached |
| Symptom | Cause | Remedy |
|---|---|---|
| Battle Short mode is enabled and an overridden shutdown fault occurs | The Shutdown lamp lights, even though the generator set continues to run. | |
| Battery fault | Contact your nearest Cummins distributor. | |
| Battery overcharged | Charge alternator fault | |
| Mains battery charge fault | Contact your nearest Cummins distributor. | |
| Low battery fluid level | Check the charger; it may not be shutting off when the charge is complete. Battery terminals getting hot Poor battery connection Clean connections, reconnect and tighten securely. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: The Shutdown lamp lights, even though the generator set continues to run.. See the table for the matching fixes.
Documented causes: Indicates that no magnetic pickup pulses were sensed for a Loss of Speed delay. If a magnetic pickup is disabled, this fault is not activated.. See the table for the matching fixes.
Documented causes: Indicates the oil pressure sensor output is out of range (OOR), high.. See the table for the matching fixes.