P0520

DTC P0520

DTC DESCRIPTOR
DTC P0520
Engine Oil Pressure (EOP) Sensor Circuit

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION




The engine oil pressure (EOP) switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the engine control module (ECM)/powertrain control module (PCM) should detect a low signal voltage input. With the engine running, the pressure switch opens, and the ECM/PCM should detect a high signal voltage input. The ECM/PCM tests the state of the EOP circuit with the ignition switch turned ON, and the engine turned OFF. If the ECM/PCM detects a high voltage input on the EOP signal circuit, DTC P0520 sets. When the oil pressure is low, the ECM/PCM sends a GMLAN serial data message to the body control module (BCM) requesting the EOP indicator turned ON. The IPC illuminates the EOP indicator when the IPC receives a serial data message from the BCM requesting the EOP indicator turned ON.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON, with the engine OFF.

CONDITIONS FOR SETTING THE DTC
- The ECM/PCM detects that the EOP sensor signal circuit is pulled high.
- 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 diagnostic test fails. The ECM/PCM displays this information in the Failure Records on the scan tool.
- The instrument panel cluster (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/PCM receives a clear code command from the scan tool.

REFERENCE INFORMATION

Schematic Reference
- Instrument Cluster Schematics
- Computers and Control Systems Schematics for the 2.0L engine
- Computers and Control Systems Schematics for the 2.2L engine
- Computers and Control Systems Schematics for the 2.4L engine

Connector End View Reference
- Instrument Panel, Gages, and Console Connector End Views
- Powertrain Control Module (PCM) Connector End Views for the 2.0L engine
- Engine Control Module (ECM) Connector End Views for the 2.2L engine
- Engine Control Module (ECM) Connector End Views for the 2.4L engine

Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs

Scan Tool Reference
Scan Tool Data List

CIRCUIT/SYSTEM TESTING

IMPORTANT: Do not turn the key to the crank position or engage the starter at any time during diagnosis.

1. Turn the ignition ON, with the engine OFF.
2. With the ignition ON, install a scan tool and observe the Engine Oil pressure Switch parameter in the IPC ECM Data List.
- If the Engine Oil Pressure Switch parameter displays Ok, disconnect the engine oil pressure switch, connect a 3-amp fused jumper wire between the signal circuit of the EOP switch and a good ground.

3. With the scan tool installed observe the Engine Oil pressure Switch parameter in the IPC ECM/PCM Data List.
- If the Engine Oil Pressure Switch parameter displays Low, check for a poor connection at the harness connector of the engine oil pressure (EOP) switch.
- If the harness connector is normal, replace the engine oil pressure switch.
- If the Engine Oil Pressure Switch parameter displays Ok, check the signal circuit of the EOP switch for an open, for a high resistance or for a short to voltage.
- If the signal circuit tests normal, check for a poor connection at the harness connector of the ECM/PCM.
- If the harness connector is normal, replace the ECM/PCM.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

- Engine Oil Pressure Sensor and/or Switch Replacement for the 2.0L engine.
- Engine Oil Pressure Sensor and/or Switch Replacement for the 2.2L engine.
- Engine Oil Pressure Sensor and/or Switch Replacement for the 2.4L engine.
- Control Module References for the ECM replacement, setup, and programming.