OBD CODE P0520 : Engine Oil Pressure Sensor/Switch Circuit

by

The OBD CODE P0520 code indicates a problem with the engine oil pressure sensor or switch circuit

. This sensor plays a crucial role in monitoring the oil pressure within your engine to ensure proper lubrication and prevent damage. The Powertrain Control Module (PCM) or Engine Control Module (ECM) relies on this information for optimal engine operation. 

Here’s a breakdown of the code:

OBD CODE P0520: Engine Oil Pressure Sensor/Switch Circuit Malfunction 

Common causes

  • Faulty oil pressure sensor/switch: The sensor itself might be malfunctioning, providing inaccurate readings to the PCM/ECM.
  • Wiring or connector issues: Damaged wires, loose connections, or corrosion within the circuit can disrupt the signal from the sensor to the PCM/ECM.
  • Low oil pressure: This can be caused by various factors, including low oil levels, a faulty oil pump, a clogged oil filter, or internal engine wear.
  • Failed instrument cluster or ECM: While rare, a problem with the vehicle’s instrument cluster or ECM can also trigger this code. 

Common symptoms

  • Illuminated check engine light and/or oil pressure warning light.
  • Fluctuating or inaccurate oil pressure gauge readings.
  • Poor engine performance, including misfires or stalls.
  • Knocking or clunking noises from the engine.
  • Reduced engine power or acceleration.
  • Engine may refuse to start or enter “limp mode”. 

Diagnosis

  1. Check oil level and quality: Ensure the oil level is within the recommended range and free of debris or metal shavings.
  2. Inspect the oil pressure sensor and wiring: Look for any signs of damage, corrosion, or loose connections.
  3. Test the sensor using a multimeter or oil pressure gauge: Measure the sensor’s resistance or the actual oil pressure and compare the values to the manufacturer’s specifications.
  4. Check for other related codes: Use an OBD-II scanner to retrieve any other codes that may be present, as they can provide additional clues about the problem. 

How to Diaginosis P0520 Code & Repairs

Repairs can range from simple fixes to more complex procedures depending on the underlying cause.

How to fix P0520 Code

  • Replace the oil pressure sensor: This is the most common repair.
  • Repair or replace faulty wiring or connectors.
  • Change the engine oil and filter.
  • Address mechanical issues affecting oil pressure: This might involve replacing a faulty oil pump or addressing internal engine wear.
  • Consult a mechanic: If you’re unsure about the diagnosis or repair process, it’s best to consult a qualified mechanic. 

Important: It is not recommended to drive with the P0520 code, especially if accompanied by other codes or a red oil pressure light, as this can indicate a serious issue that could lead to severe engine damage. 

OBD Code P307800: Throttle Valve Control Module Air Flow at Idle Too Low (01101101 Active Static) – Diagnosis & Solutions

OBD Code P26F400: Coolant Pump “C” Control Circuit Open – Active/Static in Skoda & VW Cars

OBD Code P039B00: Cylinder 1 Pressure Too High (00100100 Passive/Sporadic) – Diagnosis & Critical Implications

Leave a Comment