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.
| Code | Meaning | 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 | Check connection on W terminal of DC Charge Alternator—WH/VI to pin-9 on the Power Zone controller; Inspect function of DC charge alternator; Inspect tension of DC charge alternator drive belt; Contact Generac Mobile. |
| B+C | Loss of speed | Check connection on W terminal of DC Charge Alternator—WH/VI to pin-9 on the Power Zone controller; Inspect function of DC charge alternator; Inspect tension of DC charge alternator drive belt; Contact Generac Mobile. |
| C | Fail to crank (AUTO mode only) | See General Troubleshooting — fail to crank. |
| Symptom | Cause | Remedy |
|---|---|---|
| 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. |
| 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. |
| Unit cranks but does not start | Low fuel level | Check fuel level in tank. Verify fuel pump operation. |
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.