Cummins/Onan 10 GEAD troubleshooting: 10 fault codes and 21 symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan 10 GEAD — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| PRE HET/LOP | PRE HET/LOP lamp lights. Engine continues to operate. | Engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C) or coolant level is low. | A. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. 2B. Indicates engine oil pressure has dropped to 30 psi (207 kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 4. If engine can be stopped follow procedure in Steps 3 and 4. |
| ENG TEMP | Hl ENG TEMP lamp lights. Engine shuts down. | Engine has overheated (engine temperature has risen above 215°F/102°C) or coolant level is low. | A. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if loose. d. Reset control and restart after locating and correcting problem. Contact an authorized service center if none of the above. |
| LO OIL PRES | 4, LO OIL PRES lamp lights. Engine shuts down. | NOTE: See also step 5. a. Check oil level, lines and filters. If oil system is OK but oil level is low, replenish. Reset control and restart. Contact an authorized service center if oil pressure is not in the range of 40 to 65 psi (275 to 448 kPa). | |
| OVERCRANK | 5. OVERCRANK lamp lights and engine stops cranking. | A. Check for empty fuel tank (LPG Vapor), fuel or leaks, or plugged fuel lines and correct as required. | |
| LO OIL PRES | Engine runs, shuts down, and LO OIL PRES lamp lights. | B. Check for dirty fuel filter and replace if necessary (see Maintenance section). c. Check for dirty or plugged air filter and replace if necessary (see Maintenance section). d. Reset the control and restart after correcting the problem. Contact an authorized service center for service if none of the above. | |
| OVERSPEED | 6. Engine runs and then shuts down, OVERSPEED lamp lights. | Indicates engine has exceeded normal operating speed. Contact an authorized service center for service. | |
| SWITCH OFF | 7. 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 | 8. LO FUEL lamp lights. Engine continues to run....Or to a propane fuel supply (if not already connected). | Move the selector switch on the governor mounting LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights. | |
| OVERLOAD | 9. The OVERLOAD lamp lights. Engine shuts down. | The line circuit breaker is located in the ATS or generator set output box. If load exceeds generator current rating, the breaker will trip preventing the generator from being overloaded. Locate the source of overload and correct as necessary. Manually reset breaker to reconnect the load to the generator. | |
| O/U VOLTAGE | 10. The O/U VOLTAGE lamp lights. Engine shuts down. | Contact an authorized service center for service. |
| Symptom | Cause | Remedy |
|---|---|---|
| PRE HET/LOP lamp lights. Engine continues to operate — engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C) or coolant level is low | Engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C) or coolant level is low | If generator is powering non-critical and critical loads and cannot be shut down: reduce load if possible by turning off non-critical loads; check air inlets and outlets and remove any obstructions to airflow |
| PRE HET/LOP lamp lights. Engine continues to operate — engine oil pressure has dropped to 30 psi (207 kPa) | Engine oil pressure has dropped to 30 psi (207 kPa) | If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 4; if engine can be stopped follow procedure in Steps 3 and 4 |
| HI ENG TEMP lamp lights. Engine shuts down — engine has overheated (engine temperature has risen above 215°F/102°C) or coolant level is low | Engine has overheated (engine temperature has risen above 215°F/102°C) or coolant level is low | 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 if necessary; check for obstructions to cooling airflow and correct as necessary; check for a slipping fan belt and tighten if loose; reset control and restart after locating and correcting problem; contact an authorized service center if none of the above |
| LO OIL PRES lamp lights. Engine shuts down — engine oil pressure has dropped to 25 psi (172 kPa) | Engine oil pressure has dropped to 25 psi (172 kPa) | Check oil level, lines and filters; if oil system is OK but oil level is low, replenish; reset control and restart; contact an authorized service center if oil pressure is not in the range of 40 to 65 psi (275 to 448 kPa) |
| OVERCRANK lamp lights and engine stops cranking — possible fuel system problem | Possible fuel system problem | Check for empty fuel tank (LPG Vapor), fuel or leaks, or plugged fuel lines and correct as required; check for dirty fuel filter and replace if necessary (see Maintenance section); check for dirty or plugged air filter and replace if necessary (see Maintenance section); reset the control and restart after correcting the problem; contact an authorized service center for service if none of the above |
| Engine runs, shuts down, and LO OIL PRES lamp lights | See step 5 (OVERCRANK): check for empty fuel tank (LPG Vapor), fuel or leaks, or plugged fuel lines and correct as required; check for dirty fuel filter and replace if necessary; check for dirty or plugged air filter and replace if necessary; reset the control and restart after correcting the problem; contact an authorized service center for service if none of the above | |
| Engine runs and then shuts down, OVERSPEED lamp lights — engine has exceeded normal operating speed | Engine has exceeded normal operating speed | Contact an authorized service center for service |
| SWITCH OFF lamp flashes — Run/Stop/Remote switch is in the Stop position which will prevent automatic starting if an automatic transfer switch is used | Run/Stop/Remote switch is in the Stop position | Move the Run/Stop/Remote switch to the Remote position for automatic starting |
| LO FUEL lamp lights. Engine continues to run — interruption of natural gas supply | Interruption of natural gas supply | Connect to a propane fuel supply (if not already connected); move the selector switch on the governor mounting bracket to the PROPANE position |
| LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights — interruption of natural gas supply | Interruption of natural gas supply | Connect to a propane fuel supply (if not already connected); move the selector switch on the governor mounting bracket to the PROPANE position |
| The OVERLOAD lamp lights. Engine shuts down — load exceeds generator current rating, the breaker will trip preventing the generator from being overloaded | Load exceeds generator current rating | Locate the source of overload and correct as necessary; manually reset breaker to reconnect the load to the generator |
| The O/U VOLTAGE lamp lights. Engine shuts down | Contact an authorized service center for service | |
| 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 authorized service center for service |
| Engine will not crank — possible fault with control or starting system | Fault lamp on | Correct fault and reset control |
| Engine will not crank — possible fault with control or starting system | Poor battery cable connections | Clean the battery cable terminals and tighten all connections |
| Engine will not crank — possible fault with control or starting system | Discharged or defective battery | Recharge or replace the battery |
| Engine will not crank — possible fault with control or starting system | Emergency stop button pushed in | To reset, pull switch out and move Run/Stop/Remote switch to Stop position; then push test switch to Reset/Lamp position |
| Engine will not crank — possible fault with control or starting system | Contact an authorized service center if none of the above | |
| No AC output voltage | Field breaker is tripped | Reset breaker; contact an authorized service center if voltage buildup causes breaker to trip |
| Green RUN lamp does not light following engine startup — possible Start/Disconnect relay failure | Possible Start/Disconnect relay failure | Test light with LAMP TEST position on switch; contact an authorized service center for assistance |
| Overcrank fault — control indicates an overcrank fault if the set fails to start after three full cranking cycles | Place the Run-Stop-Remote switch in the STOP position and momentarily depress the Reset switch; wait two minutes for the starter motor to cool and then repeat the starting procedure; if the engine does not run after a second attempt at starting, refer to the Troubleshooting section |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Fault lamp on; Poor battery cable connections; Discharged or defective battery; Emergency stop button pushed in. See the table for the matching fixes.
Documented causes: Engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C) or coolant level is low. See the table for the matching fixes.
Documented causes: Engine oil pressure has dropped to 30 psi (207 kPa). See the table for the matching fixes.