The Nexus is a generator-set controller. It is used on generator sets from Generac and Nexus, including the Guardian Series Air-Cooled 10 kW unit, Guardian Series Air-Cooled 14 kW unit, Guardian Series Air-Cooled 17 kW unit and Guardian Series Air-Cooled 20 kW unit.
Used across brands: Generac, Nexus
Also fitted to: Generac 005873-1, Generac 005875-1, Generac 005885-1, Generac 005886-1, Generac 005887-1, Generac 006053-0 (17 kW), Generac 006053-1, Generac 10 KW, Generac 13 kW, Generac 14 kW, Generac 16 kW, Generac 17 kW, Generac 20 kW, Generac 6 kW, Generac 8 kW, Generac 8-20 kW, Generac Not explicitly stated, Nexus CntrlNexus001.
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| 0 | Utility failure | Crank and start engine, transfer load to Generator if Utility returns above 75% nominal for 15 seconds | |
| 1001 | Controller — Internal Harness Loop Broken—Internal harness connecting external display board to main board has become disconnected. Triggered when main board does not see communication from display board. | ||
| 1001 | Internal Harness Loop Broken—Internal harness connecting external display board to main board has become disconnected. Triggered when main board does not see communication from display board. | ||
| 1100 | Overcrank — Condition - Engine Cranks but will not Start | Unit turns over but will not start. Controller is receiving signal on Wire 18. | Problem 17 |
| 1100 | Overcrank — Condition - Engine Cranks but will not Start (5 crank attempts). Unit turns over but will not start. Controller is receiving signal on Wire 18. | Problem 17 | |
| 1100 | Overcrank — Condition - Engine Cranks but will not Start (5 crank attempts); Unit turns over but will not start. Controller is receiving signal on Wire 18. | Problem 17 | |
| 1100 | Overcrank — Default—Engine/Starter Problem. The default for overcrank alarm, because of the nature of cranking there is almost no insight into the cause of an overcrank alarm with the current sensors. | Problem 18 | |
| 1101 | Overcrank — Engine/Starter Problem | Limiting number of cranking cycles to protect the starter motor. If the engine has tried to crank for 10 times unsuccessfully, this will trigger. | |
| 1101 | Overcrank — Engine/Starter Problem. Limiting number of cranking cycles to protect the starter motor. | If the engine has tried to crank for 10 times unsuccessfully, this will trigger. | |
| 1101 | Overcrank — Engine/Starter Problem; Limiting number of cranking cycles to protect the starter motor. | Engine has tried to crank for 10 times unsuccessfully | If the engine has tried to crank for 10 times unsuccessfully, this will trigger. |
| 1101 | Overcrank — No Fuel Pressure. Low to no fuel pressure while cranking. To set, fuel pressure has to be measured as low for at least 1200 ms before the overcrank alarm is set. | Test 58 | |
| 1200 | Overspeed — ALARM | Prolonged (60 Hz on a 50 Hz unit, 72Hz on 60Hz unit) over specified Hz for 3 seconds. Possible cause: Stepper motor/mixer body assembly issue | Test 12 |
| 1200 | Overspeed — Prolonged | Over 72 Hz for 3 seconds. Possible cause: Stepper motor/mixer body assembly issue. | Test 12 |
| 1200 | Overspeed — Prolonged (60 Hz on a 50 Hz unit, 72Hz on 60Hz unit) Over specified Hz for 3 seconds. | Stepper motor/mixer body assembly issue | Test 12 |
| 1200 | Overspeed — Prolonged (60 Hz on a 50 Hz unit, 72Hz on 60Hz unit); Over specified Hz for 3 seconds. | Stepper motor/mixer body assembly issue | Test 12 |
| 1200 | Overspeed — Prolonged. Over 72 Hz for three seconds. | Test 68 | |
| 1201 | Overspeed — Prolonged—Throttle stuck open. Over 72 Hz for three seconds with the throttle stuck open. | Stuck throttle | Test 68 |
| 1204 | Overspeed — External Ignition Overspeed. CAN alarm from external ignition, threshold is >30% over nominal. | Test 68 | |
| 1205 | Overspeed — ALARM | Instantaneous (62 Hz on a 50 Hz unit, 75Hz on 60Hz unit) over specified Hz for 0.1 second (100 milliseconds). Possible cause: Stepper motor/mixer body assembly issue | Test 12 |
| 1205 | Overspeed — Instantaneous | Over 75 Hz for .1 second (100 milliseconds). Possible cause: Stepper motor/mixer body assembly issue. | Test 12 |
| 1205 | Overspeed — Instantaneous (62 Hz on a 50 Hz unit, 75Hz on 60Hz unit) Over specified Hz for 0.1 second (100 milliseconds). | Stepper motor/mixer body assembly issue | Test 12 |
| 1205 | Overspeed — Instantaneous (62 Hz on a 50 Hz unit, 75Hz on 60Hz unit); Over specified Hz for 0.1 second (100 milliseconds). | Stepper motor/mixer body assembly issue | Test 12 |
| 1205 | Overspeed — Instantaneous. Over 75 Hz for one second. | Test 68 | |
| 1206 | Overspeed — Instantaneous—Throttle stuck open. Over 75 Hz for one second with the throttle stuck open, total loss of control. | Stuck throttle | Test 68 |
| 1207 | Overspeed — ALARM | Monitors zero cross timing of the AVR to determine the alternator frequency which is a speed indicator. Set for 150 milliseconds of 4500 rpm or higher. Used if the normal ignition pulse sequence(s) are not being seen by the controller | Test 64 and Test 60 |
| 1207 | Overspeed — Monitors zero cross timing of the AVR to determine the alternator frequency which is a speed indicator. Set for 150 milliseconds of 4500 rpm or higher. Used if the normal ignition pulse sequence(s) are not being seen by the controller. | Test 64 and Test 60 | |
| 1300 | Low Oil Pressure — ALARM | Occurred while running. The default Extended alarm for low oil pressure | Check oil level and pressure |
| 1300 | Low Oil Pressure — Occurred while running | The default Extended alarm for low oil pressure. | Check oil level and pressure. Test 61 |
| 1300 | Low Oil Pressure — Occurred while running. The default Extended alarm for low oil pressure. | Check oil level and pressure. Test 61 | |
| 1300 | Low Oil Pressure — Occurred while running; The default Extended alarm for low oil pressure. | Low oil level or low oil pressure | Check oil level and pressure. Test 61 |
| 1300 | Low Oil Pressure — Occurred while running—Default. The default extended alarm for low oil pressure. | Check the oil level; Problem 28 | |
| 1400 | High Temperature — ALARM | Condition - Air Flow Impeded / Flow Issue | Check the inlet/outlet for debris; check temperature sensor and wiring |
| 1400 | High Temperature — Air Flow Impeded / Flow Issue. Check the inlet/outlet for debris. Coolant temp greater than 246 ºF (119 ºC) for 1 second. Check coolant sensor circuit for proper operation. | Problem 27; Test 114 | |
| 1400 | High Temperature — Condition - Air Flow Impeded / Flow Issue | Check the inlet/outlet for debris. Check temperature sensor and wiring. Test 62 | |
| 1401 | High Temperature — Fuel Pressure Low—Running Lean. Very low fuel pressure while running will cause an increase in engine temperature. Fuel pressure must be measured as low for 1200 ms preceding high temperature alarm to set this E-Code. | Problem 34 | |
| 1500 | Rpm Sensor — Missing Mag Pickup Pulses. | Problem 31 | |
| 1501 | RPM Sensor — ALARM | Twin Cylinder+Running. Twin Cylinder Running faults to RPM Sensor Loss. Possible Causes: air pocket in fuel line, dirty fuel, missing ignition pulse (loss of one of the primary coils) | Test 50 and Test 64 |
| 1501 | RPM Sensor — Twin Cylinder+Running | Twin Cylinder Running faults to RPM sensor loss. Possible Causes: air pocket in fuel line, dirty fuel, missing ignition pulse (loss of one of the primary coils). | Test 50 and Test 64 |
| 1501 | RPM Sensor — Twin Cylinder+Running. Twin Cylinder Running faults to RPM Sensor Loss. | Air pocket in fuel line; dirty fuel; missing ignition pulse (loss of one of the primary coils) | Test 50 and Test 64 |
| 1501 | RPM Sensor — Twin Cylinder+Running; Twin Cylinder Running faults to RPM Sensor Loss. | Air pocket in fuel line; dirty fuel; missing ignition pulse (loss of one of the primary coils) | Test 50 and Test 64 |
| 1505 | RPM Sensor — ALARM | Twin Cylinder+Cranking. Twin Cylinder Cranking faults to RPM sensor loss. Possible Cause: starter motor issue, missing ignition pulse (loss of one of the primary coils) | If engine cranks, Test 64; if engine does not crank, Problem 15 |
| 1505 | RPM Sensor — Twin Cylinder+Cranking | Twin Cylinder Cranking faults to RPM sensor loss Possible Cause: starter motor issue, missing ignition pulse (loss of one of the primary coils). | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1505 | RPM Sensor — Twin Cylinder+Cranking. Twin Cylinder Cranking faults to RPM sensor loss. | Starter motor issue; missing ignition pulse (loss of one of the primary coils) | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1505 | RPM Sensor — Twin Cylinder+Cranking; Twin Cylinder Cranking faults to RPM sensor loss | Starter motor issue; missing ignition pulse (loss of one of the primary coils) | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1511 | RPM Sensor — ALARM | Single Cylinder+Running. Single Cylinder Running RPM sensor loss. Possible Causes: air pocket in fuel line, dirty fuel. Loss of ignition pulse | Test 50 and Test 64 |
| 1511 | RPM Sensor — Single Cylinder+Running | Single Cylinder Running with Low Fuel Pressure faults to RPM sensor loss Possible Causes: air pocket in fuel line, dirty fuel. | Test 50 and Test 64 |
| 1511 | RPM Sensor — Single Cylinder+Running. Single Cylinder Running RPM sensor loss. | Air pocket in fuel line; dirty fuel; loss of ignition pulse | Test 50 and Test 64 |
| 1511 | RPM Sensor — Single Cylinder+Running; Single Cylinder Running RPM sensor loss | Air pocket in fuel line; dirty fuel; loss of ignition pulse | Test 50 and Test 64 |
| 1515 | RPM Sensor — ALARM | Single Cylinder+Cranking. Single Cylinder Cranking faults to RPM sensor loss. Possible Cause: starter motor and/or engine issue. Loss of ignition pulse | If engine cranks, Test 64; if engine does not crank, Problem 15 |
| 1515 | RPM Sensor — Single Cylinder+Cranking | Single Cylinder Cranking faults to RPM sensor loss Possible Cause: starter motor issue. | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1515 | RPM Sensor — Single Cylinder+Cranking. Single Cylinder Cranking faults to RPM sensor loss. | Starter motor and/or engine issue; loss of ignition pulse | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1515 | RPM Sensor — Single Cylinder+Cranking; Single Cylinder Cranking faults to RPM sensor loss | Starter motor and/or engine issue; loss of ignition pulse | If engine cranks, Test 64. If engine does not crank, Problem 15. |
| 1516 | Rpm Sensor — Cranking + Low Fuel. Cranking with Low Fuel Pressure faults to rpm sensor loss. | Low fuel pressure for at least 1200 ms; ignition fault; air pocket in fuel line; dirty fuel | Problem 34 |
| 1517 | Rpm Sensor — Running + Low Fuel. Running with low fuel pressure faults to rpm sensor loss. | Low fuel pressure for 1200 ms; ignition fault; air pocket in fuel line; dirty fuel | Problem 34 |
| 1518 | Rpm Sensor — No Pulse during Cranking. Rpm sensor loss, no tooth pulses sensed for 75 consecutive milliseconds while starter active. | Starter circuit issue; rpm sensor | Problem 31 |
| 1519 | Rpm Sensor — No Pulse during Running. Cranking faults to rpm sensor loss. | Starter circuit issue; rpm sensor | Problem 31 |
| 1520 | Rpm Sensor — Missing Pulses during Cranking. Cranking faults to rpm sensor loss. Starter engaged, no tooth pulses for 75 ms. | Starter circuit issue; rpm sensor alignment; low battery | Problem 31 |
| 1521 | Rpm Sensor — Missing Pulses during Running. While running, no tooth pulses for 75 consecutive milliseconds. | Rpm sensor alignment; low battery | Problem 31 |
| 1600 | Underspeed — ALARM | Condition - Unit is Overloaded (55 Hz for 60 Hz for 30 sec, 40 Hz for 50 Hz unit). Unit is Overloaded slowing engine speed, fuel supply low or throttle control problem | Problem 3, or Test 50, or Test 12 |
| 1600 | Underspeed — Condition - Unit is Overloaded | Unit is Overloaded slowing engine speed, fuel supply low or throttle control problem. | Problem 1, Test 50 or Test 12 |
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.