P0520

DTC P0520

DTC Descriptor

DTC P0520
- Engine Oil Pressure (EOP) Sensor Circuit

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






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 instrument panel cluster (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.
* The PCM receives a clear code command from the scan tool.

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 engine oil pressure (EOP) switch connector.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.

• If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, install a 3-Amp fused jumper wire between the signal circuit of the EOP switch and ground. Verify the scan tool Engine Oil Pressure Switch parameter is Low.

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

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

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Engine Oil Pressure Sensor and/or Switch Replacement for the 3.8L engine
* Programming and RelearningProgramming and Relearning