P0520

DTC P0520

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptor
DTC P0520
- Engine Oil Pressure (EOP) Sensor Circuit




Diagnostic Fault Information






Circuit/System Description

The engine oil pressure (EOP) switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the powertrain control module (PCM) should detect a low signal voltage input. With the engine running, the oil pressure switch opens and the PCM detects a high signal voltage input. The PCM tests the state of the EOP signal circuit with the ignition switch turned ON, and the engine turned OFF. When the oil pressure is low, the PCM sends a serial data message to the instrument panel cluster (IPC) requesting the EOP indicator turned ON. The IPC illuminates the EOP indicator when the IPC receives a serial data message from the PCM requesting the EOP indicator turned ON.


Conditions for Running the DTC

* The ignition is ON, with the engine ON.
* Engine temperature is 10°C (50°F) less than the last key off temperature.



Conditions for Setting the DTC

* The PCM detects that the EOP switch signal circuit is pulled high.
* The above condition is present for greater than 10 seconds.



Action Taken When the DTC Sets

* The PCM records the operating conditions at the time the diagnostic test fails. The PCM displays this information in the Failure Records on the scan tool.
* The IPC displays the engine oil pressure indicator.



Conditions for Clearing the DTC

* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.



Reference Information
Schematic Reference

* Instrument Cluster Schematics (Instrument Cluster Schematics)
* Engine Controls Schematics (Electrical Diagrams)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Instrument Cluster Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for Scan Tool Information


Circuit/System Testing

Important: Do not turn the key to the crank position or engage the starter at any time during diagnosis.



1. Ignition OFF, disconnect the harness connector at the EOP switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal B and ground.

• If greater than the specified value, test the ground circuit terminal B for an open/high resistance.

3. Ignition ON, install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Engine Oil Pressure Switch parameter is Low.

• If not Low, test the signal circuit terminal A for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

4. If all circuits test normal, replace the engine oil pressure switch.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Engine Oil Pressure Sensor and/or Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for the PCM replacement, setup, and programming