U1568 – Lost Communication with the Fuel Pump Control Module.

The ODBII 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.

The severity of ODBII code U1568 is typically considered moderate to severe.

Common Causes For: U1567 Communication Bus Off.

• 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 misdiagnosis for U1568 Lost Communication with the Fuel Pump Control Module.

• 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

Common Troubleshooting Steps

The OBD-II code U1568 indicates a “Lost Communication with the Fuel Pump Control Module.” This code typically suggests that there is a communication issue between the Engine Control Module (ECM) and the Fuel Pump Control Module (FPCM). Here are some common troubleshooting steps to diagnose and resolve this issue:

• 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.
• 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.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or damaged.
• 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.
• **Module Functionality: If possible, test the Fuel Pump Control Module separately to ensure it is functioning correctly.
• 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.
• Inspect the ECM: **Connections: Ensure that the ECM is properly connected and that there are no issues with its connectors.
• **Functionality: If other troubleshooting steps do not resolve the issue, consider testing or replacing the ECM, as it may be malfunctioning.
• Check for Interference: Look for any aftermarket accessories or modifications that may interfere with the communication between the ECM and the FPCM.
• 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.
• 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.
• Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures and wiring diagrams related to the Fuel Pump Control Module and ECM.
• 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.