P0521

DTC P0521

Diagnostic Instructions

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

DTC Descriptor

DTC P0521
- Engine Oil Pressure (EOP) Sensor Performance

Circuit Description

The engine oil pressure (EOP) sensor changes resistance based on engine oil pressure. The engine control module (ECM) monitors the signal circuit of the EOP sensor. When the oil pressure is high, the sensor resistance is high, and the ECM senses a high signal voltage. When the oil pressure is low, the sensor resistance is low, and the ECM senses a low signal voltage. The ECM sends the engine oil pressure information to the instrument panel cluster (IPC) via the class 2 serial data circuit.

Conditions for Running the DTC

* The engine is running with engine speed between 1,000 and 3500 RPM.
* Oil temperature is less than 140°C (284°F).

Conditions for Setting the DTC

The ECM does not detect a change in the engine oil pressure of at least 34.5 kPa (5 psi) over a predetermined variance of the engine speed.

Action Taken When the DTC Sets

* The ECM records the operating conditions at the time the diagnostic test fails. The ECM displays this information in the Failure Records on the scan tool.
* The IPC illuminates the EOP 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.

Circuit/System Verification

Engine idling, verify the scan tool Engine Oil Pressure Sensor indicates a range of 0.7-2.8 volts.

Circuit/System Testing

Engine idling, verify the scan tool Engine Oil Pressure Sensor parameter is between 0.7-2.8 volts.

If not in the specified range, replace the EOP sensor.

Repair Instructions

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

Engine Oil Pressure Sensor and/or Switch Replacement