U1545 – BCM Communication Failure

The ODBII code U1545 indicates a communication failure between the Body Control Module (BCM) and other modules in the vehicle’s network, suggesting a problem with data exchange or connectivity.

The severity of ODBII code U1545 is moderate to high.

Common Causes For: U1544 U1544: BCM Communication Failure

• Faulty Body Control Module (BCM)
• Poor or damaged wiring/connectors
• Corroded terminals
• Failed or malfunctioning sensors
• Software issues or programming errors
• Low battery voltage
• Intermittent electrical connections
• Faulty communication network (CAN bus issues)

Common misdiagnosis for U1545 U1545: “BCM Communication Failure”

• Faulty Body Control Module (BCM)
• Wiring issues or shorts in the communication lines
• Faulty or corroded connectors
• Issues with other control modules (e.g., PCM, ECM)
• Battery or power supply problems
• Software or firmware issues in the BCM
• Grounding problems
• Faulty sensors or actuators related to the BCM

Common Troubleshooting Steps

The OBD-II code U1545 indicates a “BCM Communication Failure,” which typically means there is a problem with the communication between the Body Control Module (BCM) and other modules in the vehicle. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Other codes may provide more context or indicate related issues.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the BCM and other modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the ground connections, as poor grounding can lead to communication issues.
• Check Power Supply:
• Ensure that the BCM is receiving the correct voltage. Use a multimeter to check the power supply to the BCM.
• Verify that the fuses related to the BCM and communication circuits are intact.
• Test the BCM:
• If possible, perform a self-test of the BCM using a scan tool. Some scan tools can communicate with the BCM to check for internal faults.
• If the BCM is not responding, it may need to be replaced.
• Inspect Other Modules:
• Check the other modules that communicate with the BCM (e.g., Engine Control Module, Transmission Control Module, etc.) for faults or communication issues.
• Ensure that these modules are functioning properly and are not causing the communication failure.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the manufacturer or a dealership to see if there are any updates available for the BCM or other related modules.
• Perform a Network Test:
• Use a scan tool to perform a network test to see if the BCM can communicate with other modules. This can help identify if the issue is isolated to the BCM or if it affects multiple modules.
• Clear Codes and Test Drive:
• After performing the above checks and repairs, clear the trouble codes using the scan tool and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs):
• Check for any TSBs related to the U1545 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues that can help in troubleshooting.
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis and repair. By following these steps, you should be able to identify and resolve the underlying cause of the U1545 code.