U1252 – Lost Communication with Fuel Pump Control Module.

The ODBII code U1252 indicates a loss of communication between the vehicle’s control module and the fuel pump control module, which may affect fuel delivery and engine performance.

The severity of ODBII code U1252 is moderate to severe.

Common Causes For: U1251 SCP (J1850) Invalid or Missing Data for Vehicle Id (VIN)

• 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

Common misdiagnosis for U1252 Lost Communication with Fuel Pump Control Module.

• Faulty fuel pump
• Bad fuel pump relay
• Wiring issues or shorts
• Faulty engine control module (ECM)
• Bad fuel pressure regulator
• Incorrectly installed or damaged connectors
• Faulty ignition switch
• Issues with the fuel system or fuel lines

Common Troubleshooting Steps

When dealing with the OBD-II code U1252, which indicates “Lost Communication with Fuel Pump Control Module,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Codes related to the fuel system or communication issues can provide additional context.
• Inspect the 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 or corroded.
• 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 Communication Issues: **CAN Bus Communication: Since U1252 is a communication-related code, check the CAN bus wiring for shorts, opens, or other issues. Use a scan tool to monitor communication between modules.
• **Other Modules: Ensure that other modules in the vehicle are functioning properly, as a fault in another module can affect communication.
• Inspect the Fuel Pump: **Operation Check: Ensure that the fuel pump is operating correctly. You can listen for the pump’s operation when the ignition is turned on or use a fuel pressure gauge to check for proper fuel pressure.
• **Fuel Pump Relay: Check the fuel pump relay for proper operation. A faulty relay can prevent the fuel pump from receiving power.
• Check for Ground Issues: Ensure that all ground connections related to the fuel pump control module and fuel pump are secure and free of corrosion.
• Reset the Codes: After performing checks and repairs, clear the codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs): Check for any manufacturer-specific TSBs related to the U1252 code or fuel pump control module issues. There may be known fixes or recalls.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or automotive technician who has experience with your specific vehicle make and model.Conclusion Troubleshooting OBD-II code U1252 involves a systematic approach to check for communication issues, inspect wiring and components, and ensure that the fuel pump and its control module are functioning correctly. Always refer to the vehicle’s service manual for specific procedures and specifications.