DTC code
P0520
Engine Oil Pressure Sensor/Switch Circuit Malfunction
Technical guide
Symptoms
- Stored trouble code and illuminated warning light
- possible engine shutdown by PCM (code P2105 may also appear)
- mechanical noises (ticking, knocking, rumbling)
- engine misfiring (if low oil pressure affects hydraulic valve lifters)
Probable causes
- Defective oil pressure switch
- damaged/corroded/disconnected wiring and connectors
- unsuitable engine oil type
- poor maintenance (infrequent oil changes)
- excessive engine wear
- failed internal components (oil pump, relief valve, timing chain tensioners)
- PCM failure (rare)
Diagnostic steps
- Record all fault codes and freeze frame data; verify oil level and condition.
- Visually inspect all wiring and connectors for damage/corrosion.
- Perform resistance, voltage, and continuity tests on wiring and switch.
- Install mechanical pressure gauge to verify actual oil pressure readings.
- Test oil pressure at idle and 3000 RPM; compare to manufacturer specifications.
- Confirm repair success by verifying scanner readings match mechanical gauge readings.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
Models most reported with this code (NHTSA)
Count of distinct owner complaints mentioning the code. US data — same engines, same failures.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0520
Nothing confirmed yet for this code. No guess is offered on purpose.
Open a case