Generac Generator Error Codes and Troubleshooting Guide
When your Generac standby generator detects a problem, it displays an error code on the controller panel and, if Mobile Link is active, sends an alert to your smartphone. Understanding what each code means helps you determine whether the issue is something you can resolve yourself (like a low oil level) or something that requires a service technician. Here is a reference guide to the most common Generac error codes and the recommended troubleshooting steps for each.
How to Read Generac Error Codes
Generac uses numeric fault codes displayed on the generator controller LCD screen. The code appears as a 4-digit number along with a brief description on newer controllers. On older models, you may see only the numeric code. The controller also illuminates a red fault light when an active code is present. To view the code, press the ENTER button on the controller panel. The current fault code and any recent alarm history will display.
Common Error Codes
1100 – Overcrank
This is the most common Generac error code. It means the engine attempted to start multiple times (typically 6 cranking cycles) but failed to reach running speed. Common causes include an empty or disconnected fuel supply (propane tank empty or gas valve closed), a dead or weak starting battery, a fouled or worn spark plug, a stale fuel issue in propane systems (rare but possible with old propane), or an engine mechanical issue preventing startup.
Troubleshooting: Check that the gas supply valve is open and the propane tank has fuel. Check the battery voltage (should be 12.5V or higher). Visually inspect the spark plug for fouling or damage. If the fuel supply and battery are confirmed good, reset the controller by pressing the OFF button, waiting 30 seconds, then pressing AUTO. If the code returns on the next start attempt, contact a service technician.
1300 – Low Oil Pressure
The engine oil pressure has dropped below the minimum threshold. This is a protective shutdown that prevents engine damage. Common causes include low oil level (the most frequent cause), oil that has degraded from extended runtime without a change, an oil pressure sensor fault, or an engine mechanical issue.
Troubleshooting: Check the oil level using the dipstick. If low, add the correct oil type and quantity specified in your owner manual. If the oil level is full, the oil may need changing (especially if the generator has been running for an extended period). After addressing the oil level, reset the controller. If the code persists with proper oil level and fresh oil, contact a service technician to evaluate the pressure sensor and engine condition.
1400 – High Temperature
The engine temperature has exceeded the safe operating threshold. Common causes include blocked airflow (debris, leaves, snow, or stored items blocking the enclosure ventilation), an extremely high ambient temperature combined with sustained heavy load, a failed cooling fan, low oil level (which affects cooling), or installation in an area with inadequate ventilation clearance.
Troubleshooting: Inspect the generator enclosure for any obstructions blocking airflow on the intake and exhaust sides. Remove debris, vegetation, or stored items. Verify that the installation meets minimum clearance requirements on all sides. Check the oil level. If the area around the generator is clear and ventilation is adequate, reset the controller. If the code returns during normal operation, contact a service technician.
1501/1505/1511/1515 – RPM Sensor Loss
The controller has lost the signal from the engine RPM sensor. The specific sub-code indicates which signal was lost and during which operating mode. This code usually indicates an RPM sensor failure, a loose or damaged sensor wiring connection, or a controller board issue. This code typically requires professional service. Check for any visibly loose wiring at the generator before calling a technician.
1600 – Underspeed
The engine speed has dropped below the minimum required RPM. Common causes include overloading (more electrical demand than the generator can supply), a fuel supply restriction, a governor or fuel system issue, or starting a large motor load that temporarily drags the engine speed down. If the code appeared during a heavy-load startup event (like an AC compressor starting), reset the controller and monitor. If it recurs during normal loads, the fuel system or governor may need professional attention.
2100 – Overload
The electrical load on the generator has exceeded its maximum rated output. The generator shut down to protect itself from damage. This occurs when too many high-demand devices are running simultaneously. Troubleshooting: Identify and reduce the electrical load. Turn off non-essential circuits or heavy-draw appliances. Reset the controller and restart. If you regularly trigger overload, your generator may be undersized for your home electrical demand, and a larger unit should be considered.
2680 – Controller Fault
An internal controller board issue has been detected. This code typically requires professional service and potential controller board replacement. Do not attempt to repair controller electronics yourself.
How to Reset After a Fault Code
After addressing the underlying cause of the fault, reset the generator by pressing the OFF button on the controller, waiting 30 seconds, then pressing the AUTO button to return the generator to automatic standby mode. The fault code should clear. If the same code returns immediately or on the next exercise/start cycle, the underlying issue has not been resolved and professional service is needed.
When to Call a Technician
Call a service technician for any code that returns after you have addressed the apparent cause and reset the controller, any RPM sensor code (1501/1505/1511/1515), any controller fault code (2680), any code you are not comfortable diagnosing yourself, and any situation where the generator will not start after troubleshooting. Annual maintenance performed on schedule prevents the majority of fault codes. Most codes related to oil, battery, and fuel are preventable with regular service.
IB Lighting carries Generac maintenance kits, batteries, and accessories that address the most common fault code causes. Browse our Generac home standby generators 10kW to 28kW collection and maintenance supplies, or call (800) 674-9019 for troubleshooting guidance and parts ordering.