Cummins/Onan HDKA troubleshooting: 121 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan HDKA — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| Fault Code Blinking | Restoring Fault Code Blinking | ||
| Code 1 | Engine Over Temperature | ||
| Code 2 | Low Oil Pressure | ||
| Code 3 | Service Check | ||
| Code 4 | Over Crank | ||
| Code 12 | Over Voltage | ||
| Code 13 | Under Voltage | ||
| Code 14 | Over Frequency | ||
| Code 15 | Under Frequency | ||
| Code 19 | Governor Actuator | ||
| Code 22 | Governor Actuator Overload | ||
| Code 27 | Voltage Sense | ||
| -01 | Fuel level in coach tanks | Prime genset fuel system | |
| 1, 2, 3, or 4 | First level faults | ||
| 33, 44 | Not assigned due to misinterpretation risk | ||
| 1 | HIGH TEMPERATURE | (Engine coolant or inverter heat sink temperature exceeded design limit) | Check the second-level fault code by touching Stop. The second-level fault will be either No. 33 or No. 34. |
| 3 | SERVICE CHECK FAULT | (A second-level fault occurred) | Check the second-level fault code by touching Stop. The second-level fault will be one of the following in this table. |
| 8 | OVERLOAD | Reduce load and restart | |
| 11 | OVERCURRENT FAULT | (AC output short) | 1. Turn off the genset line circuit breaker. If the genset no longer shuts down, the genset is probably okay—check for and repair a short circuit in the vehicle appliances, wiring or shorted battery charger transformer. 2. Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. |
| 12 | INVERTER OVERVOLTAGE FAULT | Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. | |
| 13 | INVERTER UNDERVOLTAGE FAULT | Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. | |
| 14 | INVERTER OVERFREQUENCY FAULT | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. | |
| 15 | INVERTER UNDERFREQUENCY FAULT | 1. Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. 2. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) | |
| 19 | GOVERNOR ACTUATOR FAULT | See an authorized Onan dealer. | |
| 22 | GOVERNOR ACTUATOR OVERLOAD FAULT | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. | |
| NO. 23 | LOW OIL PRESSURE CUTOFF SWITCH FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 24 | COOLANT TEMPERATURE SENDER FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 25 | ENGINE ABOVE SPEED TARGET FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 26 | ENGINE BELOW SPEED TARGET FAULT | Corrective Action: 1. Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. 2. Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute. | |
| NO. 27 | PMA SENSE LOST FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 28 | DC SENSE LOST FAULT | Corrective Action: Open the circuit breaker. If the fault does not persist, check for and disconnect excessive loads from the genset before starting. | |
| NO. 29 | HIGH BATTERY VOLTAGE FAULT | Corrective Action: 1. Check battery bank connections and reconnect if necessary so that the 12 volt batteries serving the genset are connected in parallel (12 volt) rather than in series (24 volt). 2. Select a lower battery booster charge rate. | |
| NO. 31 | OVERSPEED FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 32 | LOW CRANKING SPEED FAULT | Corrective Action: 1. Replace Fuse F2 (starter solenoid) if blown (Page 7). 2. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery and at the genset (Page 17). 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 4. Replace the engine oil with oil of proper viscosity for the ambient temperature (Page 16). (High oil viscosity can slow cranking speed.) | |
| NO. 33 | HIGH ENGINE COOLANT TEMPERATURE FAULT | Corrective Action: 1. Check the engine coolant level and add coolant and repair leaks as necessary (Page 20). 2. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset. 3. Reduce the number of appliances connected at the same time. (Note that high altitude and high ambient temperature decrease engine cooling capacity.) 4. Clean and flush the cooling system to remove coolant passage fouling. 5. If the genset overheats only underway, see the coach manufacture regarding air baffles or other means to direct cooling air into the genset. | |
| NO. 34 | HIGH INVERTER TEMPERATURE FAULT | Corrective Action: 1. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset. 2. Reduce the number of appliances connected at the same time. (Note that high altitude and high ambient temperature decrease cooling capacity.) | |
| NO. 35 | CONTROL CARD FAILURE FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 36 | ENGINE STOPPED FAULT | Corrective Action: 1. Check fuel level. (Note: The genset fuel pickup is probably higher than the vehicle engine pickup.) 2. Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute. 3. Check the engine air filter and remove any blockage (Page 17). 4. Check for mechanical damage. | |
| NO. 37 | INVALID GENSET CONFIGURATION FAULT | Corrective Action: See an authorized Onan dealer. | |
| NO. 42 | PROCESSOR FAULT | Corrective Action: See an authorized Onan dealer. | |
| No. 33 | High temperatures and temperature rises indicate that warm discharge air is recirculating back into the genset compartment or that the inlet or outlet air opening is restricted. | Find out why and correct as necessary to meet the temperature specifications. | |
| NO. 1 | HIGH TEMPERATURE—FAULT CODE NO. 1 (Engine coolant or inverter heat sink temperature exceeded design limit) | Corrective Action: Check the second-level fault code by touching Stop. The second-level fault will be either No. 33 or No. 34. | |
| NO. 2 | LOW OIL PRESSURE—FAULT CODE NO. 2 (Low oil pressure cutoff switch did not open) | Corrective Action: 1. Check engine oil level and add oil as necessary (Page 15). 2. Drain excess oil (above dipstick Full mark). | |
| NO. 3 | SERVICE CHECK FAULT—CODE NO. 3 (A second-level fault occurred) | Corrective Action: Check the second-level fault code by touching Stop. The second-level fault will be one of the following in this table. | |
| NO. 11 | OVERCURRENT FAULT—CODE NO. 11 (AC output short) | Corrective Action: 1. Turn off the genset line circuit breaker. If the genset no longer shuts down, the genset is probably okay—check for and repair a short circuit in the vehicle appliances, wiring or shorted battery charger transformer. 2. Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. | |
| NO. 12 | INVERTER OVERVOLTAGE FAULT—CODE NO. 12 (Controller not able to regulate to rated voltage) | Corrective Action: Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. | |
| NO. 13 | INVERTER UNDERVOLTAGE FAULT—CODE NO. 13 (Controller not able to regulate to rated voltage) | Corrective Action: Check whether the vehicle engine and genset share the same starting battery. If so, and this fault occurs when cranking the vehicle engine, low battery voltage may be causing this shutdown. Increase battery capacity or install a separate battery and battery charging system for the genset. | |
| NO. 14 | INVERTER OVERFREQUENCY FAULT—CODE NO. 14 (Controller not able to regulate to rated frequency) | Corrective Action: Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. | |
| NO. 15 | INVERTER UNDERFREQUENCY FAULT—CODE NO. 15 (Controller not able to regulate to rated frequency) | Corrective Action: 1. Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. 2. Have air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.) | |
| NO. 19 | GOVERNOR ACTUATOR FAULT—CODE NO. 19 (Controller sensed open or short circuit) | Corrective Action: See an authorized Onan dealer. | |
| NO. 22 | GOVERNOR ACTUATOR OVERLOAD FAULT—CODE NO. 22 (Duration of operation at or near full-duty cycle beyond design limit) | Corrective Action: Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. | |
| NO. 23 | LOW OIL PRESSURE CUTOFF SWITCH FAULT—CODE NO. 23 (Controller sensed switch still open during start—not a running fault) | Corrective Action: See an authorized Onan dealer. | |
| NO. 24 | COOLANT TEMPERATURE SENDER FAULT—CODE NO. 24 (Controller did not sense temperature change during first 5 minutes of operation) | Corrective Action: See an authorized Onan dealer. | |
| NO. 25 | ENGINE ABOVE SPEED TARGET FAULT—CODE NO. 25 (Governor unable to regulate to target speed) | Corrective Action: See an authorized Onan dealer. | |
| NO. 26 | ENGINE BELOW SPEED TARGET FAULT—CODE NO. 26 (Governor unable to regulate to target speed) | Corrective Action: 1. Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. 2. Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute. | |
| NO. 27 | PMA SENSE LOST FAULT—CODE NO. 27 (Controller unable to sense PMA frequency) | Corrective Action: See an authorized Onan dealer. | |
| NO. 28 | DC SENSE LOST FAULT—CODE NO. 28 (Controller unable to sense DC bus voltage) | Corrective Action: Open the circuit breaker. If the fault does not persist, check for and disconnect excessive loads from the genset before starting. | |
| NO. 29 | HIGH BATTERY VOLTAGE FAULT—CODE NO. 29 (Voltage across battery system greater than 17.5 volts) | Corrective Action: 1. Check battery bank connections and reconnect if necessary so that the 12 volt batteries serving the genset are connected in parallel (12 volt) rather than in series (24 volt). 2. Select a lower battery booster charge rate. | |
| NO. 33 | HIGH ENGINE COOLANT TEMPERATURE FAULT—CODE NO. 33 | 1. Check the engine coolant level and add coolant and repair leaks as necessary (Page 20). 2. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset. 3. Reduce the number of appliances connected at the same time. (Note that high altitude and high ambient temperature decrease engine cooling capacity.) 4. Clean and flush the cooling system to remove coolant passage fouling. 5. If the genset overheats only underway, see the coach manufacture regarding air baffles or other means to direct cooling air into the genset. | |
| NO. 34 | HIGH INVERTER TEMPERATURE FAULT—CODE NO. 34 | 1. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset. 2. Reduce the number of appliances connected at the same time. (Note that high altitude and high ambient temperature decrease cooling capacity.) | |
| NO. 35 | CONTROL CARD FAILURE FAULT—CODE NO. 35 | See an authorized Onan dealer. | |
| NO. 36 | ENGINE STOPPED FAULT—CODE NO. 36 | 1. Check fuel level. (Note: The genset fuel pickup is probably higher than the vehicle engine pickup.) 2. Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute. 3. Check the engine air filter and remove any blockage (Page 17). 4. Check for mechanical damage. | |
| NO. 37 | INVALID GENSET CONFIGURATION FAULT—CODE NO. 37 | See an authorized Onan dealer. | |
| NO. 38 | OVERCURRENT FAULT—CODE NO. 38 | Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. Start up with no load and let the genset run for five minutes to cool down the inverter. | |
| NO. 42 | PROCESSOR FAULT—CODE NO. 42 | See an authorized Onan dealer. | |
| NO. 43 | PROCESSOR FAULT—CODE NO. 43 | See an authorized Onan dealer. | |
| NO. 46 | INVERTER POWER SUPPLY FAULT—CODE NO. 46 | 1. Avoid running the genset while cranking the vehicle engine in installations where the genset batteries are used to supplement the vehicle engine batteries. 2. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery, vehicle frame and genset (Page 17). 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 4. Install or service a battery charging system in the vehicle if the genset is not so equipped. | |
| 29 | High Battery Voltage | A. Check Battery 1. Check battery bank connections and reconnect if necessary so that the 12 Volt batteries serving the generator set are connected in parallel (12 Volt) rather than in series (24 Volt). 2. Select a lower battery boost charge rate. | |
| 32 | Low Cranking Speed | A. Check Battery 1. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery and at the generator set. 2. Recharge or replace the battery. Refer to the battery manufacturer's recommendations. B. Replace Engine Oil Replace engine oil with oil of proper viscosity for the ambient temperature. NOTICE High oil viscosity can slow down cranking speed. | |
| 35 | Control Card Failure | A. Contact Local Dealer or Distributor | |
| 36 | Engine Stopped | A. Check Fuel Level 1. If fuel level is low, fill the fuel tank. NOTICE The generator set fuel pickup tube could be higher up in the fuel tank than the vehicle engine pickup. 2. Prime the engine fuel system by positioning the control switch to STOP/PRIME for 30 seconds. B. Check Air Filter Element Replace the air filter if dirty. C. Check for Mechanical Damage | |
| 38 | Over Current (Field Overload) | A. Reduce Load Reduce the number of connected appliances, especially air conditioners and battery chargers. | |
| 1 flash | High engine coolant temperature. | ||
| 2 flashes | Low oil pressure fault (Code 2 fault). | ||
| 3 flashes | Service fault (Code 3 fault). |
| Symptom | Cause | Remedy |
|---|---|---|
| Dizziness | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Muscular Twitching | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Vomiting | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Weakness and Sleepiness | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Inability to Think Coherently | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Engine exhaust could ignite grass or brush | Parked in high grass or brush | |
| NO AC OUTPUT VOLTAGE AT RATED ENGINE RPM | Load circuit breakers closed, circuit open between brush block and voltage regulator, brushes stuck in holder or not making good contact with slip rings, opens or grounds in rotor or stator, incorrect field voltage, F1 and F2 leads installed on wrong terminals | Locate cause of overload and correct as required. Reset breaker, or replace if bad. Check continuity of circuit breakers and replace if necessary. Check for continuity and correct if circuit is open. Release brushes if jammed in holder. Clean slip rings if dirty. Test rotor, stator per Tests [B], [C]. Replace component if defective. Test field voltage per TEST [A]. Connect brush leads to correct terminals. Set RPM per instructions in appropriate engine manual. Set control per Voltage Adjustment [G]. See TEST [H]. Perform procedure [D] and replace voltage regulator if necessary. |
| OUTPUT VOLTAGE TOO HIGH OR TOO LOW | Set AC output overloaded, broken wires or loose connections on voltage regulator assembly, brushes not OK | Remove part of the set load. Check wiring harness from regulator assembly to end bell per TEST [F]. Inspect brushes per procedure in Manual Section 4. Repair as required. Replace the voltage regulator per procedure [E] if necessary. |
| UNSTABLE OUTPUT VOLTAGE, ENGINE SPEED STABLE | Broken wires or loose connections on voltage regulator assembly, brushes not OK | Check wiring harness from regulator assembly to end bell per TEST [F]. Inspect brushes per procedure in Manual Section 4. Repair as required. |
| UNBALANCED GENERATOR OUTPUT VOLTAGE | Generator leads not connected and grounded properly, generator stator winding not continuous | Remove load at generator terminals. Check if generator leads are connected and grounded properly per TEST [C]. Test generator stator winding continuity. |
| Engine does not crank. | Is battery dead? Check CB11 circuit breaker. If okay, jumper battery cable B+ connection to B1 starter so terminal. Does engine crank? | With S11 in Start position, is battery voltage present between K11 terminal S and ground? If K11 does not energize, test per Checkout [D] and replace if bad. Is battery voltage present at B1 solenoid terminal with S11 in Start position? Check battery per Checkout [A] and recharge or replace. Check battery charger operation per Checkout [C]. Check battery cables for clean tight connections (ref. Checkout [B]). Check B1 starter solenoid and motor: if bad, repair or replace. Check B+ wiring to S11, and between S11 and K11. Check NC contacts of A11-K15. Replace if bad. |
| Engine cranks but does not start | Incorrect fuel? See Operator’s Manual recommendations. Check fuel system: fuel tank level, shut-off valves, fuel lines and connections, fuel filters, fuel pump and injection pump. Okay? Does K14 fuel solenoid energize when S11 is in Start position? | Check B+ circuit through S11. Test S11 per Checkout [G]. Test K14 per Checkout [F]. Check switch S11 per Checkout [G]. Check heater relay per Checkout [E]. Check heater wiring. |
| Engine starts but stops after running several seconds | Is a fault condition indicated by fault breaker CB12 on control panel? Check for a possible fault condition. If none, check fault monitors S1 through S4 and fault breaker CB12 for improper wiring. Check relay K12 per Checkout [H]. Is K12 good? Does DC control breaker trip after generator set is started? | Check for closing of S6 power latch switch. If switch is OK, check mechanical adjustment of K1 solenoid: is rod adjusted to correct length to allow the hold-in coil of K1 to latch? If K1 adjustment is OK and problem remains, replace engine monitor PC board. Check all B+ wiring for shorts to ground. Check fuel solenoid adjustment. |
| Engine Unstable (Hunts) | -Check: Fuel supply -Check: Fuel Lines for leakage -Check: Loose wire connection -Perform checks in step 01 -Check: Governor for binding -Check: Governor adjustments | |
| Engine Will Not Shut Off | -Check: Binding in the governor -Check: Actuator adjustment | |
| Excessive Exhaust Smoke Under Load | -Check: Intake air restrictions -Check: Overloaded generator -Check: Valve settings -Perform checks in step 01 -Check: Injection pump timing | |
| ENGINE DOES NOT CRANK | Tripped DC control breaker, Low cranking voltage | Reset the control breaker handle, Have the genset serviced if it keeps tripping. Clean and tighten or replace the positive (+) and negative (−) battery cable connectors and cables at the battery and the genset, Recharge or replace the battery |
| FAULT SHUTDOWN | Low engine oil pressure, High engine temperature | Check engine oil level, repair any leaks and fill to the proper level (p. 12), Check engine coolant level, repair any leaks and fill to the proper level (p. 14), Check V-belt tension (p. 14), Clean and service the cooling system as required to restore full cooling capacity (p. 14) |
| ENGINE LACKS POWER OR UNSTABLE | Inadequate fuel delivery, Contaminated fuel | Check for fuel (air) leaks at all fittings and tighten as necessary, Replace the fuel filter (p. 16), Connect the fuel lift pump to a container of fuel of known quality, Replace the contents of the fuel supply tank if there is a noticeable difference in performance |
| NO OUTPUT VOLTAGE | Line circuit breaker Off, Line circuit breaker Tripped | Find out why the circuit breaker was turned Off, make sure it is safe to reconnect power, and then throw the circuit breaker On. Shut down the genset and have service performed as necessary to clear the short circuit or ground fault that caused tripping. Then Reset the circuit breaker and start the genset |
| Shutdown due to high engine coolant temperature | ||
| Shutdown due to a loss of engine oil pressure | ||
| Shutdown due to a service fault | Press Stop once to cause the two-digit, second-level shutdown code to blink. (Pressing Stop again will stop the blinking.) The two-digit code consists of 1, 2, 3, 4 or 5 blinks, a brief pause, and then 1 to 9 blinks. The first set of blinks represents the tens digit and the second set of blinks the units digit of the shutdown code number. | |
| Cranking time exceeded 35 seconds | ||
| Damage to equipment and fire | Interconnections without an approved switching device | Use an approved switching device |
| Flame, cigarette, spark, pilot light, electrical arc-producing equipment and switches, or other sources of ignition near fuel fumes | Keep away from areas where fuel fumes are present | |
| Inlet Air Temperature Rise: The rise in inlet air temperature over ambient air temperature must not exceed 8° F (4.4° C). Oil Temperature Rise: The rise in engine oil temperature over ambient air temperature must not exceed 190° F (106° C). Maximum Coolant Temperature: Maximum coolant temperature is 230° F (110° C), at which point the genset will shut down | High temperatures and temperature rises. indicate that warm discharge air is recirculating back into the genset compartment or that the inlet or outlet air opening is restricted. | Find out why and correct as necessary to meet the temperature specifications. |
| High Coolant Temperature | Coolant temperature over 230°F (110°C). | Check coolant level, ensure pump belt is OK and has proper tension. Check cooling system cleanliness. |
| The genset stops | Does the genset operate correctly from the genset controls? If it does not, the problem is in the genset, not the EC-20 controller. See the genset Operator, Installation, and Service Manuals. | |
| The indicator light in the Start/Stop switch turns off | Confirm that the correct connection diagram (Figures 5 - 7) was used, then check EC 30 wiring connections. Confirm that the correct voltages are present on each terminal. Check all terminal connections on both ends of the wiring harness. Are harness connectors properly joined? | |
| Engine not getting fuel | A. Open any closed shutoff valve. b. Check fuel level and refill as necessary. c. Prime the fuel system (p.12). d. Check for fuel (air) leaks at all fittings and tighten as necessary. e. Replace the fuel filter (p. 16). | |
| Low engine temperature | A. Plug in, repair or install engine coolant and engine oil heaters. b. Replace the engine oil if it is not of the recommended viscosity for the ambient temperature. | |
| Blocked air inlet | Service as necessary. | |
| STARTING BATTERIES RUN DOWN | (Marginal battery, battery 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 (Page 17). 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. |
| 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 (Page 17). 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. 4. Increase battery cable size or run parallel cables. |
| NO POWER—GENSET RUNNING, RUN LIGHT ON | (Line circuit breaker OFF or tripped or faulty wiring) | Reset or turn “On” the line circuit breaker on the genset operator’s console. |
| GENSET WON’T STOP RUNNING—STATUS INDICATOR LIGHT ON | Faulty Stop Switch or grounded wiring | Try the genset Stop Switch if the remote Stop Switch does not work, and vice versa. Otherwise, let the genset run out of fuel. |
| GENSET WON’T STOP RUNNING—STATUS INDICATOR LIGHT OFF | Binding governor mechanism, misadjusted speed stop | Let the genset run out of fuel. |
| STATUS INDICATOR LIGHT STAYS ON | Reversed battery connections | Corrective Action: Reconnect the battery correctly (Page 17). |
| ENGINE CRANKS WHEN BATTERY CONNECTED | Faulty Start Switch or grounded wiring | Corrective Action: See an authorized Onan dealer. |
| ENGINE WON’T CRANK—FUEL PUMP WON’T STOP | Faulty Stop Switch or grounded wiring | Corrective Action: 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. Replace Fuse F1 (B+) if blown (Page 7). 3. Clean and tighten the positive (+) and negative (−) battery cable connections at the battery, vehicle frame and genset (Page 17). 4. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations. |
| Unbalanced generator set output voltage | Remove load at generator set terminals. Are generator set leads connected and grounded properly? See Test [C]. Is generator set stator winding continuous per TEST [C]? Check load for ground faults and correct as necessary. Check for correct grounding of generator set and load. Correct as necessary. Replace stator assembly. | |
| GENSET HUNTS UNDER FULL LOAD | Fuel delivery marginal, governor misadjusted | Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute. |
| GENSET WON’T STOP RUNNING—STATUS INDICATOR LIGHT ON (Faulty Stop Switch or grounded wiring) | Try the genset Stop Switch if the remote Stop Switch does not work, and vice versa. Otherwise, let the genset run out of fuel. | |
| GENSET WON’T STOP RUNNING—STATUS INDICATOR LIGHT OFF (Binding governor mechanism, misadjusted speed stop) | Let the genset run out of fuel. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Parked in high grass or brush. See the table for the matching fixes.
Documented causes: Load circuit breakers closed, circuit open between brush block and voltage regulator, brushes stuck in holder or not making good contact with slip rings, opens or grounds in rotor or stator, incorrect field voltage, F1 and F2 leads installed on wrong terminals. See the table for the matching fixes.
Documented causes: Set AC output overloaded, broken wires or loose connections on voltage regulator assembly, brushes not OK. See the table for the matching fixes.