Cummins/Onan DGDA troubleshooting: 78 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan DGDA — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning |
|---|---|
| 234 | Overspeed |
| 1433 | Emergency Stop |
| 1434 | Remote Emergency Stop |
| 121 | Speed Signal Lost |
| 2335 | Excitation Fault |
| 1123 | Shutdown After Battle Short |
| 1416 | Fail To Shut Down |
| 1131 | Battle Short Active |
| Fault Code Table | Status Indicators |
| PRE LO OIL PRES | Indicates engine oil pressure is marginally low. |
| PRE HI ENG TEMP | Indicatesengine temperature is marginally high. |
| LO OIL PRES | Indicates engine has shut down because of critically low oil pressure. |
| HI ENG TEMP | Indicates engine has shut down because of critically high temperature. |
| OVERSPEED | Indicates engine has shut down because of excessive speed. |
| OVERCRANK | Indicates engine has shut down because of a failure to start during the cranking period. |
| FAULT 1 | An undedicated fault. May be factory programmed as a shutdown or non-shutdow.n, and as a timed or non-timed fault. (Normally set for timed shutdown). |
| FAULT 2 | Same features as Fault 1 (Normally set for timed shutdown). |
| LOW ENG TEMP | Engine temperature is marginally low for starting. Indicates inoperative coolant heater. |
| LO FUEL | Indicates fuel supply is marginally low. |
| SWITCH OFF | Indicates generator set is not in automatic start operation mode. |
| 135 | Oil Pressure Sensor High |
| 141 | Oil Pressure Sensor Low |
| 143 | Pre-Low Oil Pressure Sensor |
| 144 | Coolant Temperature Sensor High |
| 145 | Coolant Temperature Sensor Low |
| 146 | Pre-High Cool Temp |
| 151 | High Coolant Temp |
| 197 | Low Coolant Level |
| 235 | Low Coolant Level |
| 359 | Fail to Start |
| 415 | Low Oil Pressure |
| 441 | Low Battery Voltage |
| 442 | High Battery Voltage |
| 1124 | Delayed Shutdown |
| 1244 | Engine Normal Shutdown |
| 1311 | Customer Inputs #1 |
| 1312 | Customer Inputs #2 |
| 1317 | Customer Inputs #3 |
| 1318 | Customer Inputs #4 |
| 1334 | Crit Scaler OR |
| 1335 | Non-Crit Scaler OR |
| 1417 | Power Down Failure |
| 1435 | Low Coolant Temperature |
| 1438 | Fail to Crank |
| 1442 | Weak Battery |
| 1443 | Battery Failed |
| 1444 | KW Overload |
| 1445 | Short Circuit |
| 1446 | High AC Voltage |
| 1447 | Low AC Voltage |
| 1448 | Under Frequency |
| 1449 | Over Frequency |
| 1461 | Loss of Field |
| 1466 | Modem Failure |
| 1468 | Network Error |
| 1469 | Speed/Hz Match |
| 1471 | Over Current |
| 1472 | Over Current |
| 2336 | Memory Error |
| 2341 | High Control Temperature |
| 2342 | Too Long in Idle |
| 2967 | Governor Fault |
| 2968 | AVR Fault |
| 2969 | LON Failure |
| 2972 | Field Overload |
| Symptom | Cause | Remedy |
|---|---|---|
| Indicates engine has begun to overheat and engine temperature has risen to approximately 220°F (105°C). | A. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. | |
| Indicates engine has overheated (engine temperature has risen above 230°F/110°C) or coolant level is low (sets with coolant level sensor). | A. Allow engine to cool down completely before proceeding with the following checks: - Check coolant level and replenish if low. - Look for possible coolant leakage points and repair as necessary. - Correct as necessary. - Contact an Onan Dealer or Distributor if none of the above. b. Check for obstructions to cooling airflow c. Check for a slipping fan belt and tighten if necessary d. Reset control and restart after locating and correcting problem. | |
| Indicates engine oil pressure has dropped to 20 psi (138 kPa). | If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure. If engine can be stopped, follow procedures in step 5. | |
| Indicates engine oil pressure has dropped to 14 psi (97 kPa). | Check oil level, lines and filters. If oil system is okay but oil level is low, replenish. Reset control and restart. Contact an Onan Dealer or Distributor if oil pressure is not in the range of 35 to 55 psi (241 to 379 kPa). | |
| OVERCRANK lamp lights and engine stops cranking. | Indicates possible fuel system problem. | A. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. b. Check for dirty or plugged air filter and replace if necessary (see MAINTENANCE section). c. Refer to Step 5. d. Reset the control and restart after correcting the problem. Contact an Onan Dealer or Distributor for service if none of the above. |
| Engine runs and then shuts down, OVERSPEED lamp lights. | Indicates engine has exceeded normal operating speed. Contact an Onan Dealer or Distributor for service. | |
| SWITCH OFF lamp flashes. | Indicates Run/Stop/Remote switch is in the Stop position which will prevent automatic starting if an automatic transfer switch is used. Move the Run/Stop/Remote switch to the Remote position for automatic starting. | |
| LO FUEL lamp lights. Engine continues to run. | Indicates engine has run out of fuel. Check fuel level and replenish as required. | |
| LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights. | Indicates engine has run out of fuel. Check fuel level and replenish as required. | |
| LO ENG TEMP lamp lights. Set is in 1 I 2-Light Panel Only. | Indicates engine coolant heater is not operating or is not circulating coolant. Check for the following conditions: a. Coolant heater not connected to power supply. Check for blown fuse or disconnected heater cord and correct as required. b. Check for low coolant level and replenish if required. Look for possible coolant leakage points and repair as required. c. Contact an Onan Dealer or Distributor if none of the above. | |
| The FAULT 1 or FAULT 2 fault lamp lights. Engine shuts down immediately, engine runs for several seconds and then shuts down, or engine continues to run. | The standard undesignated fault functions are programmed to shut down the set when a fault is sensed. Fault 1 is time delayed while Fault 2 is immediate. The nature of the fault is an optional selection that is determined when the set installation is designed. The undesignated fault functions may also be programmed for non-shutdown or non-time delay. | |
| Fault lamp lights but no fault exists. Engine gauges show oil pressure, engine temperature, and frequency (speed) are within normal limits. | The monitor board or a sensor may be at fault. Contact an Onan Dealer or Distributor for service. | |
| Engine will not crank. | Remote circuit breaker is tripped, Reset breaker and restart. Contact an Onan Dealer or Distributor if breaker trips after resetting. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Indicates possible fuel system problem.. See the table for the matching fixes.