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 P0523 Engine Oil Pressure (EOP) Sensor Circuit High Voltage
Conditions for Running the DTC
| • | The engine is running. |
| • | DTC P1635 is not present. |
Conditions for Setting the DTC
| • | 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. |
| • | The ECM receives the 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 in determining how many miles since the DTC set. The Fail Counter and the 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 .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Engine Controls Connector End Views for the 5.3L engine or to Inline Harness Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the Engine Oil Pressure Sensor parameter display greater than the specified value? | 4.6 V | Go to Step 3 | Go to Diagnostic Aids |
Does the Engine Oil Pressure Sensor parameter display less than the specified value? | 0.4 V | Go to Step 4 | Go to Step 5 | |
4 |
Is the resistance less than the specified value? | 5 ohms | Go to Step 7 | Go to Step 6 |
5 | Test the EOP sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 |
6 |
Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the EOP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
9 | Replace the EOP sensor. Refer to Engine Oil Pressure Sensor and/or Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
