Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0523: Engine Oil Pressure (EOP) Sensor Circuit High VoltageDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Engine Oil Pressure 5-Volt 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. |
| • | 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. |
Reference Information
Schematic Reference
| • | Engine Controls Schematics for the 5.3L engine |
| • | Engine Controls Schematics for the 6.0L engine |
Connector End View Reference
| • | Engine Control Module Connector End Views for the 5.3L engine |
| • | Engine Control Module Connector End Views for the 6.0L engine |
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the EOP sensor.
- Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground.
- Install a 3-amp fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 0.4 volt.
- If all circuits test normal, test or replace the EOP sensor.
| ⇒ | If greater than 1 ohm, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the ECM. |
| ⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than 0.4 volt, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Engine Oil Pressure Sensor and/or Switch Replacement for the 5.3L engine |
| • | Engine Oil Pressure Sensor and/or Switch Replacement for the 6.0L engine |
| • | Control Module References for the ECM replacement, setup, and programming |
