Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide 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 | -- | P0521 |
Engine Oil Pressure Sensor Signal Circuit | P0522 | P0522 | P0523 | P0521 |
Low Reference | -- | P0523 | -- | P0521 |
Circuit/System Description
The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit, and the 5-volt reference circuit. The engine control module (ECM) or the powertrain control module (PCM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM/PCM monitors the signal circuit of the EOP sensor to determine the engine oil pressure sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the EOP sensor voltage is high and the ECM/PCM senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM/PCM senses a low signal voltage. The ECM/PCM sends the EOP information to the instrument panel cluster (IPC) via the serial data circuit. The IPC illuminates the engine oil pressure indicator when it receives a serial data message from the ECM/PCM indicating a low engine oil pressure condition.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
| • | The ECM/PCM detects that the EOP sensor signal circuit is greater than 4.8 volts. |
| • | The above condition is present for greater than 10 seconds. |
Action Taken When the DTC Sets
| • | The ECM/PCM records the operating conditions at the time the diagnostics test fails. The ECM/PCM displays this information in the Failure Records on the scan tool. |
| • | The IPC illuminates the EOP 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. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the engine oil pressure (EOP) sensor.
- Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal 1 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground.
- Install a 3-amp fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 1. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 4.8 volts.
- If all circuits test normal, test or replace the EOP sensor.
| ⇒ | If greater than 1 ohm, test the circuit for an open/high resistance. If the circuit tests normal, replace the engine control module (ECM). |
| ⇒ | If greater than 5.2 volts, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than 4.8 volts, 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 3.5L engine |
| • | Control Module References for the ECM replacement, setup, and programming |
