P0520 critical

Engine Oil Pressure Sensor/Switch Circuit

The P0520 code means the vehicle's onboard diagnostic system has detected: Engine Oil Pressure Sensor/Switch Circuit. This is a critical severity code.

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Keep driving?
No -- stop driving
DIY difficulty
moderate
Estimated cost
$50 - $250 (parts and labor)
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Common Symptoms

  • Oil pressure warning light on dash
  • Oil pressure gauge reading abnormally
  • No oil pressure indication at all
  • Engine ticking or knocking noise
  • Check engine light on

Probable Causes (Ranked by Likelihood)

  • Faulty oil pressure sensor/switch Very High
  • Wiring or connector issue to oil pressure sensor High
  • Actually low oil pressure due to low oil level High
  • Oil pressure sensor circuit open or shorted Moderate
  • PCM fault reading oil pressure signal Low

Step-by-Step Diagnostic Procedure

  1. Check engine oil level and condition first -- top off if low

  2. Install a mechanical oil pressure gauge to verify actual oil pressure (should be 25-65 PSI at operating temp)

  3. Inspect oil pressure sensor connector for corrosion, oil contamination, or loose fit

  4. Measure oil pressure sensor resistance -- compare to manufacturer specifications

  5. Check wiring continuity from oil pressure sensor to PCM

Common Fixes by Vehicle

What techs usually find when diagnosing P0520 on specific vehicles — tap your vehicle for the fix and the exact part:

2007-2017 Chevrolet Silverado/GMC Sierra 5.3L Easy DIY

The oil pressure sensor/switch on the GM 5.3L Gen IV engine is a known failure item. It leaks oil externally from the sensor body and sends erratic signals to the gauge. Replace with ACDelco 12677836 oil pressure sensor. Located above the oil filter on the driver side of the block.

Labor: 30-45 minutes
2005-2013 Chrysler 300/Dodge Charger 5.7L Hemi Easy DIY

The oil pressure sending unit on the Hemi 5.7L fails and causes erratic gauge readings or a low oil pressure warning light. Located on the rear of the engine near the oil filter housing. Replace with Mopar 56031005 or Dorman 926-040. Use a deep socket and short extension.

Labor: 30-45 minutes
2004-2014 Ford F-150 5.4L Triton Easy DIY

The oil pressure sensor on the 5.4L Triton is located in the oil filter housing and is prone to leaking. If the oil pressure gauge reads erratically or the check engine light is on, replace the sensor with Motorcraft SW-6147. Check the oil level first -- low oil can trigger erratic readings.

Labor: 30-45 minutes

Frequently Asked Questions

Can I drive with code P0520?

Do not drive until you verify actual oil pressure with a mechanical gauge. If the sensor is simply faulty and real oil pressure is normal, you can drive. But if actual oil pressure is low, driving can destroy the engine in minutes.

How do I know if it is the sensor or actual low oil pressure?

Install a mechanical oil pressure gauge in place of the sensor. If the mechanical gauge shows normal pressure (25-65 PSI at operating temperature), the sensor is faulty. If pressure is low, you have a real oil pressure problem that needs immediate attention.

Where is the oil pressure sensor located?

The oil pressure sensor is typically located near the oil filter housing on the engine block. On GM LS engines, it is at the back of the block near the distributor location. On many 4-cylinder engines, it is near the oil filter on the front or side of the block.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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