P0520 on Chevrolet: How to Diagnose & Fix
Engine Oil Pressure Sensor/Switch Circuit Malfunction
1 Chevrolet model · 1 documented issue · $20-$120 repair
P0520 on Chevrolet by model: symptoms, diagnosis and fix
The engine oil pressure sensor/sending unit on LS truck V8s commonly fails or gets its screen clogged with sludge, sending the dash gauge bouncing, pegging high, dropping to zero, or reading falsely low—often with an 'oil pressure' warning even though actual pressure is fine. GM added a screen around the sensor mid-2007 that made the debris problem worse. A leading, cheap-to-fix false-alarm complaint that scares owners into thinking the pump failed.
Common Symptoms
- Oil pressure gauge erratic or bouncing
- Gauge pegged high or dropped to zero
- Low-oil-pressure warning with normal engine sound
- Oil pressure codes stored
How to Fix
Verify real oil pressure with a mechanical gauge first. If mechanical pressure is good, replace the oil pressure sensor/sending unit (GM 12621649 is the common LS sensor—verify fitment for your engine/year) and clean any debris from the screen/passage. If the gauge itself doesn't respond when the sensor is unplugged, the instrument-cluster stepper motor is the culprit instead. Don't replace the oil pump on a bad-reading gauge alone.
Sources for this issue (1)
P0520 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0520 mean on a Chevrolet?
P0520 stands for "Engine Oil Pressure Sensor/Switch Circuit Malfunction." This code indicates a general electrical fault in the circuit for the engine oil pressure sensor or switch. The computer monitors this circuit to know your oil pressure, and it has detected a signal that is missing, shorted, or otherwise out of the expected electrical range. This is typically a wiring or sensor problem rather than an actual loss of oil pressure, but because oil pressure is critical to engine life, it should never be ignored until confirmed. If oil pressure truly is low, serious engine damage can result. On Chevrolet it is documented across 1 model: Silverado 1500.
What are the most common causes of P0520?
The most common causes of P0520 are: Faulty oil pressure sensor or switch, Damaged, corroded, or loose wiring/connector at the sensor, Open or short in the sensor circuit wiring, Poor ground connection, Low engine oil level or genuinely low oil pressure, Failed PCM/ECM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0520 on a Chevrolet?
Published repair estimates on Chevrolet range from $20 to $120 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0520 on a different make?
View P0520 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.