P0520

P0520-ENGINE OIL PRESSURE SENSOR CIRCUIT





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

With the engine running.

- Set Condition:

The engine oil pressure never reaches the specified value to allow the MDS activation.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. DTC IS ACTIVE

NOTE: Verify that the engine oil is at the proper level. Review oil change history to verify that the oil is changed at the correct intervals and that the proper oil viscosity is used.

NOTE: Diagnose and repair any Engine Oil Pressure Sensor circuit, system voltage, or sensor supply voltage DTCs before continuing with this test.

Start the engine and allow it to reach operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

With the scan tool select View DTCs.

Is the status Active for this DTC?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC

2. ENGINE OIL/ENGINE MECHANICAL CONDITION

NOTE: The following items must be considered before determining the cause of this DTC. Failure to do so may lead to misdiagnosis.

- ENGINE MECHANICAL TOLERANCES OUT OF SPECIFICATION
- ENGINE OIL PRESSURE OUT OF SPECIFICATION
- LOW ENGINE OIL
- OIL DIRTY OR DETERIORATED (Lack of scheduled oil changes)
- CORRECT VISCOSITY
- ENGINE OIL CONTAMINATED (i.e., coolant and/or fuel)

If any of the above conditions are found, repair as necessary.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test

No

- Go To 3

3. (G6) EOP SIGNAL CIRCUIT SHORTED TO VOLTAGE





Turn the ignition off.
Disconnect the Engine Oil Pressure Sensor connector.
Disconnect the Powertrain Control Module (PCM) connector.
Turn the ignition on.
Measure the voltage of the (G6) EOP Signal circuit in the Engine Oil Pressure Sensor harness connector.

Is there any voltage present?

Yes

- Repair the (G6) EOP Signal circuit for a short to voltage.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 4

4. (G6) EOP SIGNAL CIRCUIT SHORTED TO GROUND





Turn the ignition off.
Measure the resistance between ground and the (G6) EOP Signal circuit in the Engine Oil Pressure Sensor harness connector.

Is the resistance above 100 ohms?

Yes

- Go to 5

No

- Repair the (G6) EOP Signal circuit for a short to ground.
- Perform the PCM Verification Test. PCM Verification Test

5. (G6) EOP SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT





Measure the resistance between the (G6) EOP Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Pressure Sensor harness connector.

Is the resistance above 100 ohms?

Yes

- Go to 6

No

- Repair the (G6) EOP Signal circuit for a short to the (K900) Sensor Ground circuit.
- Perform the PCM Verification Test. PCM Verification Test

6. (F855) 5 VOLT SUPPLY CIRCUIT HIGH RESISTANCE





Turn the ignition off.

Connect the Powertrain Control Module (PCM) connector.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

Using a voltmeter, perform a voltage drop test by backprobing the (F855) 5 Volt Supply circuit at the Engine Oil Pressure Sensor harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Start the engine.

Is the voltage below 0.5 volts?

Yes

- Go to 7

No

- Repair the (F855) 5 Volt Supply circuit for high resistance.
- Perform the PCM Verification Test. PCM Verification Test

7. (G6) EOP SIGNAL CIRCUIT HIGH RESISTANCE





Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

Using a voltmeter, perform a voltage drop test by backprobing the (G6) EOP Signal circuit at the Engine Oil Pressure Sensor harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Start the engine.

Is the voltage below 0.5 volts?

Yes

- Go to 8

No

- Repair the (G6) EOP Signal circuit for high resistance.
- Perform the PCM Verification Test. PCM Verification Test

8. (K900) SENSOR GROUND CIRCUIT HIGH RESISTANCE





Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

Using a voltmeter, perform a voltage drop test by backprobing the (K900) Sensor Ground circuit at the Engine Oil Pressure Sensor harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Start the engine.

Is the voltage below 0.5 volts?

Yes

- Go to 9

No

- Repair the (K900) Sensor Ground circuit for high resistance.
- Perform the PCM Verification Test. PCM Verification Test

9. ENGINE OIL PRESSURE SENSOR





Turn the ignition off.
Connect the Powertrain Control Module (PCM) connector.
Connect a jumper wire between the (G6) EOP Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Pressure Sensor harness connector.
Turn the ignition on.
With the scan tool, read the (G6) EOP Signal voltage.

NOTE: The circuit voltage should change from approximately 5.0 volts (plus or minus 0.1 volt) with the connector disconnected to 0 volts (plus or minus 0.1 volt) with the jumper wire in place.

Does the scan tool display the voltage as described above?

Yes

- Replace the Engine Oil Pressure Sensor.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 10

10. POWERTRAIN CONTROL MODULE (PCM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Pressure Sensor and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. PCM Verification Test