WOMS
P code powertrain Medium severity

P1684 Metering Oil Pump Position Sensor Circuit Malfunction

The OBD2 code P1684 indicates a malfunction in the metering oil pump position sensor circuit, which affects the engine's fuel delivery and performance

Definition

The OBD2 code P1684 indicates a malfunction in the metering oil pump position sensor circuit, which affects the engine's fuel delivery and performance

Common causes

  • Faulty metering oil pump position sensor
  • Damaged wiring or connectors in the sensor circuit
  • Poor electrical connections
  • Short circuit or open circuit in the sensor circuit
  • Faulty engine control module (ECM)
  • Incorrect sensor installation or alignment
  • Contaminated or damaged sensor components

Common misdiagnoses

  • Faulty Metering Oil Pump
  • Wiring Issues or Short Circuits
  • Faulty Engine Control Module (ECM)
  • Incorrect Oil Level or Quality
  • Other Sensor Malfunctions (e.g., crankshaft or camshaft position sensors)
  • Fuel System Issues
  • Vacuum Leaks
  • Ignition System Problems

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Inspect the Wiring and Connectors

    Visually inspect the wiring and connectors associated with the metering oil pump position sensor. Look for

  3. 3. Damaged, frayed, or corroded wires

  4. 4. Loose or disconnected connectors

  5. 5. Signs of moisture or dirt that could affect the connection

  6. 6. Test the Sensor

    Use a multimeter to test the metering oil pump position sensor

  7. 7. Check the resistance of the sensor according to the manufacturer's specifications

  8. 8. If the resistance is out of range, the sensor may be faulty and need replacement

  9. 9. Check the Power and Ground

    Verify that the sensor is receiving the correct voltage and has a good ground connection

  10. 10. Use a multimeter to check for voltage at the sensor connector

  11. 11. Ensure that the ground connection is solid and free of corrosion

  12. 12. Inspect the Metering Oil Pump

    If the sensor and wiring are in good condition, inspect the metering oil pump itself for any mechanical issues or blockages that could affect its operation

  13. 13. Clear the Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using the OBD-II scanner

  14. 14. Take the vehicle for a test drive to see if the code reappears

  15. 15. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues or fixes related to the P1684 code

  16. 16. Seek Professional Help

    If the issue persists after performing the above steps, consider seeking assistance from a qualified mechanic or technician who has experience with diesel engines and OBD-II diagnostics.Additional Notes: - Always refer to the vehicle's service manual for specific diagnostic procedures and specifications. - Safety precautions should be taken when working on vehicles, including disconnecting the battery when inspecting electrical components. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P1684 code