WOMS
U code network High severity

U1568 Lost Communication with the Fuel Pump Control Module

The OBD2 code U1568 indicates that there is a communication failure between the vehicle's main control module and the fuel pump control module, which may affect the operation of the fuel pump

Definition

The OBD2 code U1568 indicates that there is a communication failure between the vehicle's main control module and the fuel pump control module, which may affect the operation of the fuel pump

Common causes

  • Faulty Fuel Pump Control Module
  • Damaged wiring or connectors
  • Poor ground connection
  • Blown fuse
  • Faulty Engine Control Module (ECM)
  • Corroded terminals
  • Intermittent electrical issues
  • Software issues or updates needed
  • Fuel pump failure
  • Issues with the vehicle's CAN bus communication

Common misdiagnoses

  • Faulty fuel pump
  • Bad fuel pump relay
  • Wiring issues or shorts
  • Defective fuel pump control module
  • Issues with the engine control module (ECM)
  • Corroded connectors or terminals
  • Faulty ignition switch
  • 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. This can provide more context and help identify related issues

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the Fuel Pump Control Module for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or damaged

  4. 4. Test the Fuel Pump Control Module

    Power and Ground: Verify that the Fuel Pump Control Module is receiving the correct power and ground signals. Use a multimeter to check voltage and ground continuity

  5. 5. Module Functionality

    If possible, test the Fuel Pump Control Module separately to ensure it is functioning correctly

  6. 6. Check for Short Circuits or Open Circuits

    Use a multimeter to check for any short circuits or open circuits in the wiring between the ECM and the FPCM. This includes checking for continuity in the communication lines

  7. 7. Inspect the ECM

    Connections: Ensure that the ECM is properly connected and that there are no issues with its connectors

  8. 8. Functionality

    If other troubleshooting steps do not resolve the issue, consider testing or replacing the ECM, as it may be malfunctioning

  9. 9. Check for Interference

    Look for any aftermarket accessories or modifications that may interfere with the communication between the ECM and the FPCM

  10. 10. Perform a Network Test

    If the vehicle is equipped with a CAN (Controller Area Network) system, use a scan tool to perform a network test to check for communication issues across the network

  11. 11. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  12. 12. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific make and model of the vehicle. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the U1568 code