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) should detect a low signal voltage input. With the engine running, the pressure switch opens, and the ECM should detect a high signal voltage input. The ECM tests the state of the EOP circuit with the ignition switch turned ON, and the engine turned OFF.

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

CONDITIONS FOR SETTING THE DTC
- The ECM detects that the EOP sensor signal circuit is pulled high.
- The above condition is present for greater than 5 seconds.

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 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 powertrain control module (PCM) 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.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the EOP switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.
- If greater than 1 ohm, test the ground circuit for an open/high resistance.
3. Ignition ON, install a 3-amp fused jumper wire between the signal circuit and ground. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
- If not Low, test the signal circuit of the EOP switch for an open/high resistance. If the circuit tests normal replace the ECM.
- If low, replace the EOP switch.

REPAIR INSTRUCTIONS

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

- 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