The Microprocessor Regulated is a generator-set controller. It is used on generator sets from Cummins/Onan, including the 3.3KY, 3.6 KY, 3.6KY and 3.6MKY.
| Code | Meaning | Remedy |
|---|---|---|
| 12 | OVERVOLTAGE FAULT—CODE NO. 12 | See an authorized Onan dealer. |
| 12 | Overvoltage | |
| 13 | UNDERVOLTAGE FAULT—CODE NO. 13 | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. |
| 13 | Undervoltage | |
| 14 | OVERFREQUENCY FAULT—CODE NO. 14 | See an authorized Onan dealer. |
| 14 | Overfrequency | |
| 15 | UNDERFREQUENCY FAULT—CODE NO. 15 | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. |
| 15 | Underfrequency | |
| 27 | VOLTAGE SENSE FAULT—CODE NO. 27 | See an authorized Onan dealer. |
| 27 | Voltage Sense Lost | |
| 29 | HIGH BATTERY VOLTAGE FAULT—CODE NO. 29 | 1. Check battery bank connections and reconnect if necessary so that the 12 volt batteries serving the genset are connected in parallel (12 v |
| 29 | High Battery Voltage | |
| 3 | SERVICE CHECK FAULT—CODE NO. 3 | Check the second-level fault code by pressing STOP once. The second-level fault code will have two-digits. The faults are listed in numerical order in this table. |
| 3 | Service Check Fault | |
| 32 | Low Cranking Speed Sense | |
| 33 | Fault Code 33 | |
| 35 | Control Card Failure | |
| 36 | Genset Stopped Without Fault Condition | |
| 38 | Field Overload (Overvoltage) | |
| 4 | OVERCRANK FAULT—CODE NO. 4 | 1. Check and fill the fuel tank, as necessary. (Note: The genset fuel pickup is probably higher than the boat engine pickup.) 2. Prime the engine fuel system by holding the control switch at Stop/Prime for 30 seconds. 3. Open any closed fuel valves. 4. Secure the spark plug lead on the spark plug (Page 20). 5. Replace the spark plug (Page 20). 6. Service the air cleaner (Page 19). |
| 4 | Overcrank | |
| 41 | Generator Rotor Fault | |
| 42 | Processor Fault | |
| 45 | Speed Sense Fault | |
| 48 | Field Sense Fault | |
| 51 | Processor Failure | |
| CODE NO. 32 | LOW CRANKING SPEED FAULT—Cranking speed less than 180 rpm for more than 2 seconds | 1. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery and at the genset. 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 3. Replace engine oil with oil of proper viscosity for ambient temperatures (Page 7). (High oil viscosity can slow down cranking speed.) |
| CODE NO. 35 | CONTROL CARD FAILURE FAULT—Microprocessor EEPROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 36 | ENGINE STOPPED FAULT—Engine stopped without command by controller | 1. Check and fill the fuel tank, as necessary. (Note: The genset fuel pickup is probably higher than the boat engine pickup.) 2. Secure the spark plug lead on the spark plug (Page 20). 3. Replace the spark plug (Page 20). 4. Service the air cleaner (Page 19). 5. Check for mechanical damage. |
| CODE NO. 37 | INVALID GENSET CONFIGURATION FAULT—Genset configuration is preprogrammed at the factory | See an authorized Onan dealer. |
| CODE NO. 38 | OVERCURRENT FAULT—Low power factor loads | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) |
| CODE NO. 41 | GENERATOR ROTOR FAULT—Controller unable to sense field or output voltage | See an authorized Onan dealer. |
| CODE NO. 42 | PROCESSOR FAULT—Microprocessor ROM error during self-test | See an authorized Onan dealer. |
| CODE NO. 43 | PROCESSOR FAULT—Microprocessor RAM error during self-test | See an authorized Onan dealer. |
| CODE NO. 45 | SPEED SENSE FAULT—Controller unable to sense quadrature frequency | See an authorized Onan dealer. |
| CODE NO. 47 | IGNITION FAULT—Controller unable to sense ignition | See an authorized Onan dealer. |
| CODE NO. 48 | GENERATOR FIELD SENSE FAULT—Controller unable to sense field voltage | See an authorized Onan dealer. |
| NO. 38 | OVERCURRENT FAULT—CODE NO. 38 (Low power factor loads) | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) |
| NO. 41 | GENERATOR ROTOR FAULT—CODE NO. 41 (Controller unable to sense field or output voltage) | See an authorized Onan dealer. |
| NO. 42 | PROCESSOR FAULT—CODE NO. 42 (Microprocessor ROM error during self-test) | See an authorized Onan dealer. |
| NO. 43 | PROCESSOR FAULT—CODE NO. 43 (Microprocessor RAM error during self-test) | See an authorized Onan dealer. |
| NO. 45 | SPEED SENSE FAULT—CODE NO. 45 (Controller unable to sense quadrature frequency) | See an authorized Onan dealer. |
| NO. 47 | IGNITION FAULT—CODE NO. 47 (Controller unable to sense ignition) | See an authorized Onan dealer. |
| NO. 48 | GENERATOR FIELD SENSE FAULT—CODE NO. 48 (Controller unable to sense field voltage) | See an authorized Onan dealer. |
| STATUS INDICATOR LIGHT DEAD | Faulty connections, no battery voltage | 1. Try the genset Start Switch if the remote Start Switch does not work, and vice versa. 2. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset. 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. |
| Symptom | Cause | Remedy |
|---|---|---|
| Black smoke exits the tailpipe. | Service the air cleaner. | |
| Cranking voltage dips below 6 volts | Low battery charge, poor connections, long cables | Have the vehicle propulsion engine running while trying to start the genset—the battery charging alternator may be able to maintain starting voltage high enough to get the genset started. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. Increase battery cable size or run parallel cables. |
| Dizziness | GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Generator output connections must be made by a qualified electrician | Make generator output connections only by a qualified electrician in accordance with applicable codes. | |
| Generator sets use substances that can cause health risks | Use appropriate personal protective equipment when exposed to fuel, oil, coolant, wet batteries, grease, cleaning agents, or other substances. Use proper containers for transport, storage, and disposal of waste substances. Follow local regulations. | |
| Inability to Think Coherently | GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| Muscular Twitching | GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired. | |
| NO POWER—GENSET RUNNING, STATUS LIGHT ON | (Line circuit breaker OFF, or tripped due to short circuit or overload) | 1. Turn on or reset the line circuit breaker on the genset (Page 2-3). 2. Turn on or reset the line circuit breakers on the main distribution panel in the vehicle. |
| STARTER ENGAGES-DISENGAGES | (Cranking voltage dips below 6 volts—low battery charge, poor connections, long cables) | 1. Have the vehicle propulsion engine running while trying to start the genset—the battery charging alternator may be able to maintain starting voltage high enough to get the genset started. 2. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset. 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 4. Increase battery cable size or run parallel cables. |
| STARTING BATTERIES RUN DOWN | (Marginal batteries, connections, or charging system or, parasitic loads) | 1. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset. 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 3. Have a battery charging system installed or serviced in the vehicle. |
| STATUS INDICATOR LIGHT DEAD (Faulty connections, no battery voltage) | 1. Try the genset Start Switch if the remote Start Switch does not work, and vice versa. 2. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset. 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. | |
| STATUS INDICATOR LIGHT GOES OUT WHILE CRANKING—NO START | (Internal short circuit caused automatic-reset circuit protective device to trip) | Try starting again. See an authorized Onan dealer if the status indicator light flashes and then goes out again without the engine starting. |
| The engine cranks but fails to start. | A. Check the fuel tank and fill if necessary. b. Open any closed fuel shut off valve. c. Check engine oil level and add oil as necessary. d. Service the air cleaner. e. Secure the spark plug lead on the spark plug. f. Replace the spark plug. | |
| The engine cranks slowly. | A. Disconnect the air conditioner and other large loads. b. Clean and tighten the positive (+) and negative (- ) battery cable connections at the battery and the genset. c. Recharge the battery. Refer to the battery manufacturer’s recommendations. d. Change the engine oil to oil having the proper viscosity for the ambient temperature. See Table 1. | |
| The engine fails to crank. | A. Try starting at the genset rather than at the remote control. b. Replace the fuse on the control panel if it has blown. c. Clean and tighten the positive (+) and negative (- ) battery cable connections at the battery and the genset. d. Recharge the battery. Refer to the battery manufacturer’s recommendations. |
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.