The EC-AGS+ is a generator-set controller. It is used on generator sets from Cummins/Onan, including the HDKA, HDKB and HDKC.
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| -01 | Fuel level in coach tanks | Prime genset fuel system | |
| 1 | ENGINE OVER TEMPERATURE—CODE NO. 1 (During normal operation engine coolant temperature exceeded 239° F [115° C] for 10 seconds) | 1. Check engine coolant level, add coolant as necessary and repair any leaks. 2. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset and clean out dirt fouling the radiator passages. 3. Run fewer appliances at the same time to keep down engine temperature. (Note that high altitude and high ambient temperature decrease engine cooling capacity.) 4. Look for loose or broken fan belts and have them serviced. | |
| 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. |
| 1, 2, 3, or 4 | First level faults | ||
| 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. | |
| 2 | LOW OIL PRESSURE—CODE NO. 2 (During normal operation engine oil pressure dropped to less than 14 psi for 3 seconds—switch closed) | 1. Check engine oil level, add oil as necessary and repair any leaks. 2. Drain the excess oil if the level is above Full on the dipstick. If the level is too high the crankshaft can whip the oil into foam, which the pump can’t pump. | |
| 22 | GOVERNOR ACTUATOR OVERLOAD FAULT | Reduce the number of connected appliances, especially when air conditioners and battery chargers are running. | |
| 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. |
| 3 | SERVICE CHECK—CODE NO. 3 (A second-level fault occurred) | Check the second-level fault code by momentarily pressing Stop. The second-level fault will be one of the following in this table. | |
| 33, 44 | Not assigned due to misinterpretation risk | ||
| 38 | During normal voltage regulation Field Voltage exceeded 180 VAC for 10 seconds | 1. Reduce the number of air conditioners running at the same time, and other appliances that cause low power factor. (The lower the power factor of a motor or compressor, the more current it draws per kilowatt. The genset Controller, in turn, must boost field voltage to meet the higher demand for current imposed by low power factor.) 2. Have the air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause a very low power factor.) | |
| 4 | THE STARTER ENGAGES AND DISENGAGES (Low cranking voltage) | 1. Have the vehicle propulsion engine running while trying to start the genset. Its charging alternator may be able to maintain a high enough battery terminal voltage to start the genset. 2. Service the battery as necessary by cleaning and tightening connections, recharging or replacing the battery or replacing damaged battery cables. | |
| 41 | While field flashing during cranking, the Controller sensed that the rotor circuit was shorted to ground | See an authorized Onan dealer. | |
| 42 | During startup the genset Controller detected a ROM memory error | See an authorized Onan dealer. | |
| 43 | During startup the genset Controller detected a RAM memory error | See an authorized Onan dealer. | |
| 45 | After start disconnect the Controller lost speed sense [quadrature zero crossings] for 0.25 seconds | See an authorized Onan dealer. | |
| 8 | OVERLOAD | Reduce load and restart | |
| ACTUATOR OVERLOAD-CODE NO. 22 | Due to connected overload or low engine performance, the Controller maintained the governor actuator at full-duty cycle—maximum pulse-width-modulated square-wave signal [PWM]—for 60 consecutive seconds | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Check all fuel fittings for fuel and air leaks and tighten as necessary. Reprime. 3. Replace the engine air filter and clean the spark-arrest muffler (p. 3-4). 4. Replace the fuel filter (p. 3-6). | |
| ACTUATOR SHORTED OR OPEN-CODE NO. 19 | At startup the Controller sensed an open or shorted governor actuator/harness | See an authorized Onan dealer. | |
| CODE NO. 14 | After the starter was engaged Frequency jumped to more than 70 Hz for 40 milliseconds or to more than 66 Hz 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. Reprime. | |
| CODE NO. 15 | During normal operation Frequency fell to less than 54 Hz for more than 8 seconds | 1. Push the line circuit breaker to OFF and restart the genset. If the genset now runs, run it with fewer connected loads, especially those with high motor starting loads such as air conditioners. 2. Check all fuel fittings for fuel and air leaks and tighten as necessary. Reprime. 3. Replace the engine air filter and clean the spark-arrest muffler (p. 3-4). 4. Replace the fuel filter (p. 3-6). | |
| Code 1 | Engine Over Temperature | ||
| Code 12 | Over Voltage | ||
| Code 13 | Under Voltage | ||
| Code 14 | Over Frequency | ||
| Code 15 | Under Frequency | ||
| Code 19 | Governor Actuator | ||
| Code 2 | Low Oil Pressure | ||
| Code 22 | Governor Actuator Overload | ||
| Code 24 | Faulty Temperature Sender | ||
| Code 27 | Voltage Sense | ||
| Code 29 | High Battery Voltage | ||
| Code 3 | Service Check | ||
| Code 32 | Low Cranking Speed | ||
| Code 35 | Control Card Failure | ||
| Code 36 | Engine Stopped | ||
| Code 4 | Over Crank | ||
| EE CHECKSUM FAULT-CODE NO. 35 | During startup the genset Controller detected an EE memory error | See an authorized Onan dealer. | |
| ENGINE OVER TEMPERATURE-CODE NO. 1 | ENGINE OVER TEMPERATURE—CODE NO. 1 | During normal operation engine coolant temperature exceeded 239° F [115° C] for 10 seconds | 1. Check engine coolant level, add coolant as necessary and repair any leaks. 2. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset and clean out dirt fouling the radiator passages. 3. Run fewer appliances at the same time to keep down engine temperature. (Note that high altitude and high ambient temperature decrease engine cooling capacity.) 4. Look for loose or broken fan belts and have them serviced. |
| FAULTY ENGINE TEMPERATURE SENDER-CODE NO. 24 | After 10 minutes of normal operation the Controller checked for and sensed an open temperature sender/harness | See an authorized Onan dealer. | |
| Fault Code Blinking | Restoring Fault Code Blinking | ||
| HIGH BATTERY VOLTAGE-CODE NO. 29 | During startup the Controller sensed that battery system voltage was greater than 19.2 volts for 5 milliseconds or greater than 19.2 volts for 1 second will running | 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. | |
| LOW OIL PRESSURE-CODE NO. 2 | LOW OIL PRESSURE—CODE NO. 2 | During normal operation engine oil pressure dropped to less than 14 psi for 3 seconds—switch closed | 1. Check engine oil level, add oil as necessary and repair any leaks. 2. Drain the excess oil if the level is above Full on the dipstick. If the level is too high the crankshaft can whip the oil into foam, which the pump can’t pump. |
| MECHANICAL FAULT-CODE NO. 36 | The Controller declared this fault because engine speed fell below 1000 RPM for 0.5 seconds, though not by Controller action | ||
| 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. 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. 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. 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 | Corrective Action: See an authorized Onan dealer. | |
| 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. |
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.