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Diagnostic Tool

Generac Error Code Database

Don't panic. Enter the error code displayed on your controller to find the cause and the fix immediately.

Common Fault Codes

Preventive Maintenance

Is your generator due for maintenance?

Prevent errors before they happen. Use our calculator to find the exact oil capacity and maintenance kit for your specific model.

Find Oil & Parts
System Status
Ready to Run
Service Interval 85% Life Remaining

Understanding Generac Fault Codes

Modern Generac generators are equipped with an Evolution Controller that continuously monitors engine health. When a critical parameter falls outside safe ranges, the controller shuts down the generator and displays a diagnostic code.

Most Common Error Codes

Code 1505 - RPM Loss

Often indicates a weak battery, failed sensor, or fuel supply issue.

Code 1501 - Overcrank

Generator attempted to start but couldn't achieve proper RPM.

Pro Tip

Many error codes can be prevented with regular maintenance. Check your oil every 50 hours of operation. A well-maintained generator rarely throws error codes during an emergency.