Cummins/Onan DHA Series troubleshooting: 12 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan DHA Series — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Remedy |
|---|---|---|
| *Low oil pressure | Low oil pressure shutdown. | Check— a. Oil level. Replenish if necessary. b. Sensor. Faulty sensor will shut down engine. c. Refer to engine service manual for troubleshooting guide for oil system. |
| *High engine temperature | High engine temperature shutdown. | Check— a. Coolant level. Replenish if necessary. b. City water cooled sets. Check water flow, valves, etc. c. Check sensor; check thermostat. d. Radiator model, check fan belts, radiator for obstructions, etc. |
| Overspeed | Overspeed shutdown. | Check governor and throttle linkages for freedom of movement. Check overspeed switch. |
| *Low oil pressure | Low oil pressure light ON. | Disconnect wire at TB11-30. Light No shutdown. ON after relay reset. Replace engine monitor board. |
| *High engine temperature | High engine temperature light ON. | Disconnect wire at TB11-31. Light No shutdown. ON after relay reset. Replace engine monitor board. |
| Symptom | Cause | Remedy |
|---|---|---|
| Engine stops cranking and fault lamp lights, after cranking approximately 75 seconds. | See engine service manual for troubleshooting fuel system. After correcting problem, reset engine monitor relay by placing Run-Stop/Reset-Remote switch to Stop/Reset, then back to the required running position. | |
| Fault lamp lights immediately after engine starts. | Overspeed condition as engine starts. | |
| Fault lamp lights and engine shuts down after running for a period. | Check the following: a. Oil level. Engine will shut down if sensor is closed. b. Check engine manual for troubleshooting oil system. c. High engine temperature. Check coolant level; check water flow (city water cooled systems); check radiator for free air flow, and fan belts for tightness. See engine manual for troubleshooting cooling system. d. Check for faulty oil pressure sensor or faulty high engine temperature sensor. | |
| Engine runs, shuts down and cranks for 75-seconds. Cranking cycle stops; fault lamp lights. | Check fuel supply. | |
| Fault lamp lights, no fault exists. | To check a no-fault condition, disconnect leads from TB11 terminals 29, 30 and 31. If fault lamp lights with leads disconnected, replace engine monitor board. Reconnect leads. | |
| Overcrank fault lamp lights and engine stops cranking after approximately 75-seconds. | See engine service manual for troubleshooting fuel system. After correcting fault, reset engine monitor relay by placing Run-Stop/Reset-Remote switch to Stop/Reset position, depressing Reset button, then to the required running position. | |
| Overspeed light ON, no shutdown. | Disconnect wire at TB11-29. Light ON after reset; replace engine monitor board. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Overspeed condition as engine starts.. See the table for the matching fixes.