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.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0521 Engine Oil Pressure (EOP) Sensor Performance
Conditions for Running the DTC
The engine is running.
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. |
Diagnostic Aids
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
Refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Instrument Panel, Gages, and Console Component Views , Engine Control Module Connector End Views for the 6.0L engine or Engine Control Module Connector End Views for the 7.0L engine | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the Engine Oil Pressure Sensor parameter display values that vary within the specified values when idling and accelerating the engine? | 0.7-2.5 V 880 kPa (127.6 psi) 8 kPa (1.16 psi) | Go to Diagnostic Aids | Go to Step 3 |
3 | Replace the engine oil pressure (EOP) sensor. Refer to Engine Oil Pressure Sensor and/or Switch Replacement for the 6.0L engine or Engine Oil Pressure Sensor and/or Switch Replacement for the 7.0L engine. Did you complete the replacement? | -- | Go to Step 4 | -- |
4 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
