DTC Descriptor
DTC P0521: Engine Oil Pressure (EOP) Sensor Performance.Diagnostic Fault Information
Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Engine Oil Pressure 5-Volts Reference Circuit | P0522 | P0522 | P0523 | P0521 |
Engine Oil Pressure Sensor Signal Circuit | P0522 | P0523 | P0523 | P0521 |
Low Reference | -- | P0523 | -- | P0521 |
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 1000 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 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 ECM receives a clear code command from the scan tool. |
Reference Information
Schematic Reference
| • | Engine Controls Schematics for the 5.3L engine |
Connector End View Reference
| • | Engine Control Module Connector End Views for the 5.3L engine |
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
With the scan tool installed and the engine idling, the Engine Oil Pressure Sensor parameter should indicate a range of 0.7-2.8 volts.
Circuit/System Testing
- Ignition ON, Engine ON, verify the scan tool Engine Oil Pressure Sensor parameter is within 0.7 V - 2.8 V.
| ⇒ | If not within the range of 0.7 V - 2.8 V, replace the EOP sensor. |
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Engine Oil Pressure Sensor and/or Switch Replacement for the 5.3L engine
