The Power Zone Autolight (optional) is a generator-set controller. It is used on generator sets from Generac, including the MLTS Export Power Option and MLTS Standard Unit.
| Symptom | Cause | Remedy |
|---|---|---|
| A | Low engine oil pressure or high engine coolant temperature | See General Troubleshooting —low oil pressure & high engine coolant temperature. |
| A+C | Engine overspeed or engine underspeed | 1. Check connection on W terminal of DC Charge Alternator—WH/VI to pin-9 on the Power Zone controller. 2. Inspect function of DC charge alternator. 3. Inspect tension of DC charge alternator drive belt. 4. Contact Generac Mobile. |
| B+C | Loss of speed | 1. Check connection on W terminal of DC Charge Alternator—WH/VI to pin-9 on the Power Zone controller. 2. Inspect function of DC charge alternator. 3. Inspect tension of DC charge alternator drive belt. |
| Blockage in radiator | Inspect radiator shroud and ducting for blockage and remove any foreign matter. | |
| C | Fail to crank (AUTO mode only) | See General Troubleshooting —fail to crank |
| Damaged or loose electrical cord | Inspect the mast electrical cord for damage and check the cord connections inside the control box. | |
| Faulty thermostat | Contact a GMASD to replace. | |
| Generator output incorrect | Check the incoming voltage to the ballast driver by checking the available voltage on the GFCI receptacle. Incoming voltage should be 120V ± 5V. If voltage is incorrect, the generator may require service. | |
| High coolant temperature shutdown | Low coolant level | Add coolant if needed. Allow engine to cool, then check coolant level in radiator. Restart engine and check coolant temperature. Stop engine immediately if coolant temperature is 210 °F (99 °C) or more. |
| Illuminated LED indicates fault | See Troubleshooting | |
| Incorrect mix/frozen radiator | Thaw the radiator with an external heat source and flush the coolant system with the correct coolant mixture. | |
| Leakage in coolant hoses, engine block, or water pump | Inspect for visible leaks. Verify tension of water pump serpentine drive belt. Remove load on generator and restart engine. Verify coolant temperature and shut engine down immediately if it starts to overheat. Refer to the OEM engine operator’s manual for additional information on engine overheating. | |
| Loose lighting connections | Inspect the connections inside the mast junction box and each mast light housing/socket. | |
| Low oil pressure shutdown | Low oil level | Verify oil level on dipstick. Add oil, if needed. |
| Mast lights off, checking inside control box | Loose lighting connections | Inspect the connections inside the control box. |
| Mast lights off, checking outside control box | Light fixture is too hot | Allow light to cool 10–15 minutes before restarting. |
| Oil leaking from engine | Inspect the engine for leaks. | |
| PAS engaged | Verify PAS is off. | |
| Restricted air filter | Inspect air filter for blockage. Refer to OEM engine operator’s manual for additional information. | |
| Unit cranks but does not start | Low fuel level | Check fuel level in tank. Verify fuel pump operation. |
| Water pump failure | Contact a GMASD to replace. |
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.