P0520

The P0520 diagnostic trouble code means the PCM has identified a engine oil pressure sensor/switch circuit problem. This code indicates that a sensor or its circuit is not providing expected readings to the engine management system. Faulty sensor data can cause the PCM to make incorrect adjustments, affecting engine performance. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Cruise control not functioning. Poor engine performance. Incorrect sensor data shown on scan tool. Speedometer reading incorrectly. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Sensor out of calibration. Open or shorted sensor wiring. Water intrusion in sensor connector. Physical damage to sensor. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored trouble codes and freeze frame data. Locate the specific sensor referenced by the code. Inspect the sensor connector for corrosion, damage, or loose pins. Test the sensor output using a multimeter or scan tool live data. Check the wiring between the sensor and the PCM for opens or shorts. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Powertrain (P) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.