U2028 – Lost Communication with Body Control Module (BCM).

The ODBII code U2028 indicates that there is a communication failure between the vehicle’s control module and the Body Control Module (BCM), which may affect various electrical functions and systems in the vehicle.

The severity of OBDII code U2028 is generally considered moderate.

Common Causes For: U2027 Invalid Data Received from Body Control Module (BCM).

• Faulty Body Control Module (BCM)
• Damaged wiring or connectors
• Corroded terminals
• Poor ground connection
• Faulty communication network (CAN bus)
• Malfunctioning power supply to the BCM
• Software issues or programming errors
• Other module failures affecting communication

Common misdiagnosis for U2028 Lost Communication with Body Control Module (BCM)”.

• Faulty Body Control Module (BCM)
• Wiring issues or shorts in the communication lines
• Faulty or corroded connectors
• Issues with the power supply to the BCM
• Problems with other control modules
• Software or firmware issues in the BCM
• Faulty fuses related to the BCM
• Grounding issues in the vehicle’s electrical system

Common Troubleshooting Steps

When dealing with the OBD-II code U2028, which indicates “Lost Communication with Body Control Module (BCM),” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Sometimes, other codes can provide context or indicate related issues.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors related to the BCM for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or pushed back.
• Check Power and Ground: **Power Supply: Verify that the BCM is receiving the correct voltage. Use a multimeter to check the power supply to the BCM.
• **Ground Connections: Ensure that the ground connections for the BCM are secure and free of corrosion.
• Inspect the BCM: **Physical Condition: Check the BCM for any signs of physical damage or water intrusion.
• **Reprogramming: If the BCM has been replaced, ensure that it has been properly programmed to the vehicle.
• Test Communication Lines: **CAN Bus: Use a scan tool to check the communication on the CAN bus. If other modules are not communicating, there may be a fault in the bus itself.
• **Scope Testing: If available, use an oscilloscope to check for proper signal patterns on the communication lines.
• Check for Intermittent Issues: **Temperature Sensitivity: Sometimes, issues can be temperature-related. Monitor the vehicle’s performance under different conditions.
• **Vibration: Check if the issue occurs when the vehicle is in motion or over bumps, which could indicate a loose connection.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the BCM and other modules. Reconnect and see if the code reappears.
• Update Software: Check if there are any software updates available for the BCM or other related modules. Sometimes, manufacturers release updates to fix communication issues.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented solutions for known issues.
• Replace the BCM (if necessary): If all other troubleshooting steps fail and the BCM is determined to be faulty, consider replacing it. Ensure proper programming and configuration after replacement.1
• Seek Professional Help: If you are unable to resolve the issue, it may be best to consult a professional mechanic or dealership with experience in diagnosing and repairing communication issues. By following these steps, you should be able to identify the root cause of the U2028 code and take appropriate action to resolve it.