Generac Generator Code 1505: Low Oil Pressure Shutdown
Quick Answer
Generac 1505 low oil pressure is a critical shutdown that requires immediate attention. Unlike many Generac codes that are sensor or starting issues, 1505 means the engine was running and lost oil pressure - which causes bearing damage within seconds if not stopped. Generac standby generators have a dedicated low-oil pressure shutdown solenoid that is separate from the oil pressure sensor.
Generac 1505 low oil pressure is a critical shutdown that requires immediate attention. Unlike many Generac codes that are sensor or starting issues, 1505 means the engine was running and lost oil pressure - which causes bearing damage within seconds if not stopped. Generac standby generators have a dedicated low-oil pressure shutdown solenoid that is separate from the oil pressure sensor. This is important: the solenoid itself can fail and cause a false 1505 even when oil pressure is actually fine. Before assuming the worst, check the oil level first (with the engine OFF and cool), then check the oil pressure sender wiring for corrosion. If oil level is good, start the engine in manual mode and immediately check for the 1505 alarm. If it appears within 10 seconds, the oil pump or bearings may have failed. If it takes minutes to appear, the sender or solenoid is likely the issue.
What Does the 1505 Code Mean?
1505 means the engine lost oil pressure while running. Check oil level first. If oil is full, the oil pressure sender or shutdown solenoid may have failed (common false alarm source).
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Symptoms You May Notice
- 1505 alarm on controller
- Engine was running then shut down abruptly
- Oil warning light on generator panel
- Engine may have made knocking sound before shutdown
- Generator failed to provide power during outage
Can you reset a Generac generator to clear the 1505 code?
Press ALARM RESET on the controller. Only reset after verifying oil level is adequate. Do not repeatedly reset and run with suspected low oil pressure.
Tools Required for Diagnosis
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
With the generator OFF and engine cool (wait 10 minutes if
With the generator OFF and engine cool (wait 10 minutes if recently running), pull the oil dipstick and check the level. Oil should be between the two marks. If low, add the oil weight specified on the engine tag (typically 5W-30 or 10W-30 synthetic).
Locate the oil pressure sender on the engine block (small sensor
Locate the low-oil shutdown solenoid (separate from the sender
After replacing the faulty component, add fresh oil if needed,
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
| Part Name | OEM Number | Estimated Price |
|---|---|---|
| Generac Low Oil Pressure Shutdown Solenoid0C3029 · $25–$45 | 0C3029 | $25 – $45 |
| Generac Oil Pressure Sender0G8442 · $20–$40 | 0G8442 | $20 – $40 |
| Synthetic Motor Oil 5W-30N/A · $8–$12 | N/A | $8 – $12 |
Repair vs. Replace Calculator
Frequently Asked Questions
Can 1505 be a false alarm?
My Generac used 1505 during a storm. Did I lose power protection?
How often should I change Generac oil?
Related Generac Generator Error Codes
Models Known to Experience 1505 Errors
This repair applies to most Generac generators with this error code. Common model numbers include:
Guardian 22kW 7043, Guardian 24kW 7210, Guardian 16kW 7035, EcoGen 15kW, Protector 20kW
Last verified for technical accuracy on March 15, 2026