The Digital Electronic Governing is a generator-set controller. It is used on generator sets from Cummins/Onan, including the MDKB.
| Code | Meaning | Remedy |
|---|---|---|
| 1 | HIGH ENGINE TEMPERATURE | 1. Add coolant as necessary and repair leaks (Page 18). 2. Replace the engine thermostat, which might not be opening fully (Page 21). 3. Clean the raw water tubes in the heat exchanger, which might be clogged with scale (Page 22). 4. Flush the coolant system to remove coolant passage fouling (Page 18). |
| 1 | HIGH ENGINE TEMPERATURE—CODE NO. 1 (Engine coolant temperature exceed design limit) | 1. Check for and clean a blocked sea water strainer. If above the water line, fill the strainer with water to assist priming. 2. Check engine coolant level and add coolant as necessary. 3. Check for kinked or leaking hoses and reconnect, reroute or replace. 4. Check the V-belt that drives the coolant pump and service as necessary 5. Inspect the siphon break (if provided) for proper operation. 6. Check for a worn raw water impeller and replace as necessary 7. Clean the heat exchanger |
| 1 | HIGH ENGINE TEMPERATURE—CODE NO. 1 (Engine coolant temperature exceeds design limit) | 1. Check for and clean a blocked sea water strainer. If above the water line, fill the strainer with water to assist priming. 2. Check engine coolant level and add coolant as necessary. 3. Check for kinked or leaking hoses and reconnect, reroute or replace. 4. Check the V-belt that drives the coolant pump and service as necessary (p. 4-13). 5. Inspect the siphon break for proper operation (p. 4-8). 6. Check for a worn raw water impeller and replace as necessary (p. 4-12). 7. Clean the heat exchanger (p. 4-8). 8. Check the bottom of the hull for any blockage at the through-hull fitting. 9. Replace the coolant thermostat, which might not be opening fully (p. 4-14). 10. Drain and clean the coolant system to remove coolant passage fouling (Page 4-7). |
| 1 or 2 digit code | Status light on the generator will repeatedly blink a 1 or 2 digit code after a protective shutdown | |
| 12 | HIGH AC VOLTAGE—CODE NO. 12 (After voltage regulation was enabled Output Voltage jumped to more than 125% of rated for 75 milliseconds or to more than 115% of rated for 3 seconds) | 1. Check for a tripped generator set circuit breaker, reset if necessary, and run with fewer loads. (A breaker tripping under load can cause generator set voltage to overshoot.) 2. Check all fuel fittings and filters for fuel and air leaks and tighten as necessary. (Air bubbles can disrupt generator set frequency/voltage.) 3. Prime the engine fuel system for at least 30 seconds (p. 3-3). |
| 12 | OVERVOLTAGE | See an authorized Onan dealer. |
| 13 | LOW AC VOLTAGE—CODE NO. 13 (After voltage regulation was enabled Output Voltage fell to less than 90% of rated for 5 seconds) | 1. Push the generator set line circuit breaker OFF and disconnect the PTO, if so equipped. If the generator set now runs and voltage and frequency are normal, reduce the number of electrical and mechanical (PTO) loads. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the generator set will run out of fuel before the propulsion engines.) 3. Check all fuel fittings and filters for fuel and air leaks and tighten as necessary. (Air bubbles can disrupt generator set frequency/voltage.) 4. Replace fuel filters (p. 4-6). |
| 13 | UNDERVOLTAGE | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. |
| 14 | HIGH AC FREQUENCY—CODE NO. 14 (After the starter was engaged Frequency jumped to more than 70 Hz for 40 milliseconds or to more than 2% over nominal for 6 seconds) | 1. Check for a tripped genset circuit breaker, reset it if necessary, and run with fewer connected loads. 2. Check all fuel fittings for fuel and air leaks and tighten as necessary and reprime. |
| 14 | Overfrequency | Check engine speed, loads, governor actuator operation, fuel supply, control plugs fully seated, quad leads fully seated in connector to control, quad winding resistance |
| 15 | LOW AC FREQUENCY—CODE NO. 15 (During normal operation Frequency fell to less than 90% of nominal for more than 8 seconds) | Push the genset line circuit breaker OFF. If the genset now runs, reduce the number of loads. |
| 15 | Underfrequency | Check engine speed, loads, governor actuator operation, fuel supply, control plugs fully seated, quad leads fully seated in connector to control, quad winding resistance |
| 17 | Overprime | Check battery voltage, fuel supply, start/stop switch (local and remote), shorted wiring |
| 2 | LOW OIL PRESSURE—CODE NO. 2 (Low oil pressure) | Check the engine oil level and add or drain oil as necessary (p. 4-3). Repair any oil leaks. |
| 22 | Actuator Overload | Check load, fuel supply, intake restriction, governor actuator operation; Perform checks in step 01; Check exhaust back pressure; Perform checks in step 02; Check field windings, proper field resistance reading, open to ground, brush condition and contact |
| 23 | Faulty Oil Pressure Sender | Check oil level, grounded or shorted sender lead, sender resistance (low); Perform checks in step 01; Check oil pressure (mechanical) |
| 24 | Faulty Temperature Sender | Check coolant level, open or loose sender lead, sender resistance (high); Perform checks in step 01; Check coolant temperature |
| 27 | Loss of Voltage Sense | Check AC output, sense lead connections, control plugs fully seated, sense leads fully seated in connector to control, field windings, proper field resistance reading, open to ground, brush condition and contact, grounded or shorted main windings |
| 29 | High Battery Voltage | Check battery voltage, battery connections, battery charge rate |
| 3 | SERVICE CHECK | Check the second-level shutdown code by pressing STOP once. The second-level shutdown code will have two-digits. The shutdowns are listed below in numerical order. |
| 3 | SERVICE CHECK—CODE NO. 3 (A fault with a 2-Digit Fault Code Number occurred) | Check the 2-Digit fault code by Pushing and Releasing Stop. The 2-Digit fault will be one of the following in this table. (Does not apply to Digital Display.) |
| 3 | Service fault | Press Stop once to cause the two-digit shutdown code to blink |
| 35 | Control Card EE Checksum | Check verify fault |
| 36 | Engine Stopped | Check fuel supply, mechanical engine damage, output voltage, loads, quad leads fully seated in connector to control, control plugs fully seated; Perform checks in step 01; Check governor actuator operation, field windings, proper field resistance reading, open to ground, brush condition and contact, grounded or shorted quad windings |
| 37 | Invalid Set Configuration | Check configuration number |
| 38 | Field Overflow | Check output voltage, frequency, loads, air inlet; Perform checks in step 01; Check field windings, proper field resistance reading, open to ground, brush condition and contact, main stator resistance |
| 4 | OVERCRANK | 1. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 2. Open any closed fuel valves. 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| 4 | OVERCRANK—CODE NO. 4 (Cranking time exceeded 20 to 60 seconds, depending on ambient temperature) | 1. Check fuel level and refill as necessary. 2. Open any closed fuel supply and return valves. 3. Prime the engine fuel system for at least 30 seconds 4. Service the battery as necessary by cleaning and tightening connections, recharging or replacing the battery or replacing damaged battery cables 5. Replace the fuel filters and reprime 6. Check all fuel fittings for fuel and air leaks, tighten as necessary and reprime. 7. Change the engine oil to oil of the proper viscosity for the ambient temperature |
| 4 | OVERCRANK—CODE NO. 4 (Cranking time exceeded 20 to 60 seconds, depending on engine temperature) | 1. De-energize the PTO clutch, if so equipped. 2. Check fuel level and refill as necessary. (Note: The generator set fuel pickups are probably higher than the propulsion engine fuel pickups.) 3. Open any closed fuel supply and return valves. 4. Prime the engine fuel system for at least 30 seconds (p. 3-3). 5. Service as necessary by cleaning and tightening battery connections, recharging or replacing the battery or replacing damaged battery cables (p. 4-2). 6. Remove combustion air or exhaust system blockages. 7. Check all fuel fittings for fuel and air leaks and tighten as necessary. 8. Replace fuel filters (p. 4-6). 9. Check for contaminated fuel by connecting to a source of known fuel quality. 10. Change the engine oil to oil of the proper viscosity for the ambient temperature. High oil viscosity can slow down cranking speed. |
| 4 | Shutdown due to a failure to start within the time allowed for cranking | |
| 41 | Grounded Rotor | Check fuel supply, field windings, proper field resistance reading, open to ground, brush condition and contact |
| 42 | Control Card ROM | Check verify fault |
| 43 | Control Card RAM | Check verify fault |
| 45 | Speed Sense Loss | Check quad leads fully seated in connector to control, control plugs fully seated, field windings, proper field resistance reading, open to ground, brush condition and contact, grounded or shorted quad windings |
| 48 | Control Card Field Voltage Sense | Check verify fault |
| 58 | High Exhaust Temp | Check broken or loose switch leads, exhaust temperature switch S5, raw water flow |
| 61 | Emergency Shutdown | Check customer input connections, K5 relay operation (if equipped) |
| 7 | LOSS OF RAW WATER FLOW | 1. Open the sea cock. 2. Close the sea cock and clean the sea water strainer. If the strainer is above the water line, fill it with water to assist priming. Secure the strainer cover and reopen the sea cock. 3. Reconnect or replace any disconnected or leaking raw water hoses (Page 19). 4. Remove any blockage from the strainer on the through-hull fitting on the bottom side of the hull. 5. Replace the raw water impeller (Page 23). |
| 7 | LOSS OF RAW WATER FLOW—CODE NO. 7 (Low raw water pressure in heat exchanger) | 1. Open the sea cock. 2. Check for a blocked sea water strainer and clean it out. If above the water line, fill the strainer with water to assist priming. 3. Check for kinked or leaking hoses and reconnect, reroute or replace. 4. Check for a worn raw water impeller and replace as necessary (p. 4-12). 5. Check the bottom of the hull for any blockage at the through-hull fitting. |
| 7 | Shutdown due to a loss of raw water flow for engine and exhaust cooling | |
| CODE NO. 14 | After the starter was engaged Frequency jumped to more than 70 Hz for 40 milliseconds or to more than 2% over nominal for 6 seconds | 1. Check for a tripped generator set circuit breaker, reset if necessary, and run with fewer loads. (A breaker tripping under load can cause generator set frequency to overshoot.) 2. Check all fuel fittings and filters for fuel and air leaks and tighten as necessary. (Air bubbles can disrupt frequency.) |
| CODE NO. 15 | During normal operation Frequency fell to less than 90% of nominal for more than 8 seconds | 1. Push the generator set line circuit breaker OFF and de-energize the PTO clutch, if so equipped. If the generator set now runs, reduce the number of electrical and mechanical (PTO) loads, especially those with high motor starting loads, such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the generator set will run out of fuel before the propulsion engines.) 3. Prime the engine fuel system for at least 30 seconds (p. 3-3). 4. Remove combustion air or exhaust system blockages. 5. Check all fuel fittings for fuel and air leaks and tighten as necessary. (Air bubbles can disrupt frequency.) 6. Replace fuel filters (p. 4-6). 7. Check for contaminated fuel by connecting to a source of known fuel quality. |
| CODE NO. 15 | UNDERFREQUENCY—Engine governor unable to maintain rated frequency | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 17 | OVER-PRIME—Prime mode exceed 5 minutes | Check for and remove any object that may be holding either control switch (remote or local) in the prime position. |
| CODE NO. 22 | GOVERNOR OVERLOAD—Maximum allowable time at full-duty cycle was exceeded | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 4. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 5. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 6. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 22 | Maximum allowable time at full-duty cycle was exceeded | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the generator set will run out of fuel before the propulsion engines.) 3. Remove combustion air or exhaust system blockages. 4. Check all fuel fittings for fuel and air leaks and tighten as necessary. 5. Replace fuel filters (p. 4-6). 6. Check for contaminated fuel by connecting to a source of known fuel quality. |
| CODE NO. 23 | FAULTY OIL PRESSURE SENDER—Controller sensed grounded sender | See an authorized Onan dealer. |
| CODE NO. 24 | FAULTY TEMPERATURE SENDER—Controller sensed open sender | See an authorized Onan dealer. |
| CODE NO. 27 | LOSS OF VOLTAGE SENSE—Controller unable to sense output voltage | See an authorized Onan dealer. |
| CODE NO. 29 | HIGH BATTERY VOLTAGE—Battery system at more than 19.2 volts if 12 VDC system, or 38.4 volts if 24 volt system | 1. Check battery bank connections and reconnect if necessary to supply 12 volts or 24 volts, as appropriate. 2. Select a lower battery boost charge rate. |
| CODE NO. 35 | CONTROL CARD FAILURE—Microprocessor EEPROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 36 | ENGINE STOPPED—Engine stopped without command by controller | 1. Open any closed fuel supply valves. 2. Check the fuel tank and fill as necessary. (Note: The arrangement of pickup tubes in the fuel supply tank probably is such that the genset will run out of fuel before the propulsion engines.) 3. Check for mechanical damage and service as necessary. 4. Remove any blockage in the combustion air inlet (front grille) or exhaust system. 5. Tighten loose fuel line fittings so that air cannot be drawn in by genset lift pump suction. 6. Drain and/or replace the fuel filter (Page 16) and prime the fuel system (Page 8). 7. Drain and/or replace fuel supply system filters and prime the fuel system (Page 8). |
| CODE NO. 37 | INVALID GENSET CONFIGURATION—Controller cannot determine genset operating parameters | See an authorized Onan dealer. |
| CODE NO. 38 | FIELD OVERLOAD—High field voltage induced by high rotor temperature or low power factor loads | 1. Remove blockages to generator air flow at the front inlet grill and right side, if enclosed. 2. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 3. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) |
| CODE NO. 41 | GROUNDED ROTOR—F+ grounded | See an authorized Onan dealer. |
| CODE NO. 42 | PROCESSOR FAILURE—Microprocessor ROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 43 | PROCESSOR FAILURE—Microprocessor RAM error during self-test | See an authorized Onan dealer. |
| CODE NO. 48 | PROCESSOR FAILURE—Controller unable to sense field voltage | See an authorized Onan dealer. |
| CODE NO. 58 | HIGH EXHAUST TEMPERATURE—Exhaust temperature exceeded design limits | 1. Check for and reconnect or replace any disconnected or leaking raw water hoses (Page 19). 2. Check for a and replace a worn raw water impeller(Page 23) |
| Symptom | Remedy |
|---|---|
| Cranking will discontinue in 20 to 60 seconds, depending on engine temperature. | See Troubleshooting (Section 9) if the genset does not start after several tries. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.