P0523

DTC P0521, P0522, or P0523

Diagnostic Instructions

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

DTC Descriptors
DTC P0521
^ Engine Oil Pressure (EOP) Sensor Performance

DTC P0522
^ Engine Oil Pressure (EOP) Sensor Circuit Low Voltage.

DTC P0523
^ Engine Oil Pressure (EOP) Sensor Circuit High Voltage

Diagnostic Fault Information





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).
* DTC P0641 is not present.
* DTC P1635 is not present.

Conditions for Setting the DTC

P0521

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.

P0522
* The ECM detects that the EOP sensor signal circuit is less than 0.4 volt.
* The above condition is present for greater than 9 seconds.

P0523
* The ECM detects that the EOP sensor signal circuit is greater than 4.6 volts.
* The above condition is present for greater than 9 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Reference Information
Schematic Reference

Instrument Cluster Schematics (Instrument Cluster Schematics)
Connector End View Reference

Component Connector End Views (Component Connector End Views)
Description and Operation

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

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Control Module References)for scan tool information

Circuit/System Verification

1. Engine running, observe the scan tool Engine Oil Pressure Sensor parameter. The reading should be between 41-448 kPa (6-65 psi).
2. Verify the engine oil pressure, refer to Oil Pressure Diagnosis and Testing (5.3L) (Oil Pressure Diagnosis and Testing (5.3L))Oil Pressure Diagnosis and Testing (6.0L) ().

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the engine oil pressure (EOP) sensor.
2. Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal 1 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground.

• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 8 kPa (1.2 psi).

• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 2. Verify the scan tool Engine Oil Pressure Sensor parameter is greater than 550 kPa (80 psi).

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

6. If all circuits test normal, test or replace the EOP sensor.

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 (Control Module References)for the ECM replacement, setup, and programming