P0520

Engine Oil Pressure Sensor/Switch A Circuit

Engine oil pressure Generic OBD-II High

What it means

P0520 indicates a fault in the engine oil pressure sensor/switch "A" circuit. It's an electrical/sensor code — most often a failed sensor, wiring, or connector — but because it also disables a reliable oil-pressure warning, the safe first step is to verify actual oil pressure with a mechanical gauge before ruling out a real low-pressure condition.

High

Can I keep driving? Drivable, but with caution — the code is in the sensor circuit, so your oil-pressure warning may be unreliable; confirm actual oil pressure is good before continuing.

Real-world scan data

Seen in

1,508

scans in the past year

Found in

0.2%

of scans

0.4%

of scans that found faults

Appears alongside · share of P0520 scans

P0683in 45.0% of scans

P0110in 41.5% of scans

P0100in 27.1% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Oil pressure gauge reads erratically, zero, or pegged high
Oil pressure warning light on or flickering
No oil-pressure reading on the dash

Common causes

Most likely first

Faulty oil pressure sensor/switchLikely
Open or short in the sensor circuit wiringCommon
Corroded or loose sensor connectorCommon
Genuinely low oil pressure or an oil leak (must be ruled out)Less often
Failed instrument cluster or ECM (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data, then confirm real oil pressure with a mechanical gauge before assuming it's only a sensor — this rules out a dangerous low-pressure condition.
Inspect the sensor connector and wiring for damage, corrosion, or a short/open.
Replace the oil pressure sensor/switch if actual pressure is good but the signal is faulty.
Address any real low-pressure or leak issue found, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0520?+

Only after you've confirmed oil pressure is actually normal. The code is a sensor-circuit fault, but because it can mask a real low-pressure problem, verify pressure with a mechanical gauge first.

Can I just clear P0520?+

Not until the circuit is diagnosed. If it's a wiring or sensor fault the code returns, and clearing it could hide a genuine oil-pressure issue.

Read & clear P0520 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX