WOMS
P code powertrain Medium severity

P2559 Fuel Pump Control Module Performance

The OBD2 code P2559 indicates that the fuel pump control module is not performing as expected, which may affect the fuel pump's operation and overall engine performance

Definition

The OBD2 code P2559 indicates that the fuel pump control module is not performing as expected, which may affect the fuel pump's operation and overall engine performance

Common causes

  • Faulty fuel pump control module
  • Wiring issues or damaged connectors
  • Poor ground connections
  • Faulty fuel pump
  • Low fuel pressure
  • Malfunctioning fuel pressure regulator
  • Software issues in the engine control module (ECM)
  • Corroded or damaged pins in the fuel pump control module connector

Common misdiagnoses

  • Faulty fuel pump
  • Fuel pump relay issues
  • Wiring or connector problems
  • Faulty fuel pressure regulator
  • Engine control module (ECM) issues
  • Incorrect fuel level sensor readings
  • Fuel filter blockage
  • Battery or charging 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. Addressing related codes can help pinpoint the issue

  2. 2. Inspect the Fuel Pump Control Module

    Locate the Fuel Pump Control Module and visually inspect it for any signs of damage, corrosion, or loose connections

  3. 3. Ensure that the module is securely mounted and that all connectors are clean and free of debris

  4. 4. Check Wiring and Connectors

    Inspect the wiring harness and connectors leading to the fuel pump and the control module for any signs of wear, fraying, or damage

  5. 5. Look for any short circuits or open circuits in the wiring

  6. 6. Test the Fuel Pump

    Use a multimeter to check the fuel pump's voltage and ground connections. Ensure that the pump is receiving the correct voltage when the ignition is turned on

  7. 7. If possible, perform a bench test on the fuel pump to ensure it operates correctly

  8. 8. Check Fuel Pump Relay and Fuses

    Inspect the fuel pump relay and associated fuses. Replace any blown fuses and test the relay to ensure it is functioning properly

  9. 9. Examine the Fuel System

    Check the fuel filter for clogs or restrictions that could affect fuel flow

  10. 10. Ensure that the fuel lines are not kinked or damaged

  11. 11. Test the Fuel Pressure

    Use a fuel pressure gauge to check the fuel pressure at the fuel rail. Compare the readings to the manufacturer's specifications

  12. 12. Low fuel pressure can indicate a failing fuel pump or a clogged filter

  13. 13. Check for Ground Issues

    Ensure that the Fuel Pump Control Module has a good ground connection. Poor grounding can lead to performance issues

  14. 14. Inspect the ECM

    If all other components check out, the issue may lie with the Engine Control Module itself. Check for software updates or reprogramming needs

  15. 15. Clear Codes and Test Drive

    After performing repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns.1

  16. 16. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the P2559 code for your specific vehicle make and model. Manufacturers may have specific fixes or recommendations.1

  17. 17. Seek Professional Help

    If you are unable to resolve the issue after these steps, consider seeking help from a professional mechanic or automotive technician who has experience with fuel system diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P2559 code