U1907 – BCM Communication Failure

The ODBII code U1907 indicates a communication failure between the Body Control Module (BCM) and other modules in the vehicle’s network, suggesting a problem with data transmission or connectivity.

The severity of ODBII code U1907: BCM Communication Failure is moderate.

Common Causes For: U1906 U1906: “CAN Communication Malfunction”

• Faulty Body Control Module (BCM)
• Poor or damaged wiring/connectors
• Corroded terminals
• Malfunctioning CAN bus
• Software issues or programming errors
• Low battery voltage
• Intermittent electrical connections
• Faulty or damaged sensors or modules communicating with the BCM

Common misdiagnosis for U1907 U1907: 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 U1907 indicates a communication failure between the Body Control Module (BCM) and other modules in the vehicle’s network. 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: **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 damaged.
• Check Power and Ground: Verify that the BCM is receiving the correct voltage and ground. Use a multimeter to check the power supply and ground connections to the BCM.
• Test the BCM: If possible, test the BCM for proper operation. This may involve using a scan tool to perform BCM diagnostics or checking for software updates.
• Inspect Other Modules: Since the U1907 code indicates a communication issue, check other modules in the network (e.g., Engine Control Module, Transmission Control Module) for faults or communication errors.
• Check for Short Circuits: Inspect the wiring for any short circuits that may be affecting communication between the BCM and other modules.
• Look for Intermittent Issues: If the problem is intermittent, try to replicate the issue under different conditions (e.g., temperature changes, vehicle movement).
• Perform a Network Test: Use a scan tool capable of performing a network test to check for communication between modules. This can help identify which module is not communicating properly.
• Reset the System: Clear the trouble codes using the OBD-II scanner and see if the code returns. Sometimes, a reset can resolve temporary communication issues.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the U1907 code for your specific vehicle make and model. Manufacturers may have specific fixes or recommendations.1
• Replace the BCM (if necessary): If all other troubleshooting steps fail and the BCM is determined to be faulty, consider replacing it. Ensure that the new BCM is programmed and configured correctly for your vehicle.1
• Seek Professional Help: If you are unable to diagnose or resolve the issue, consider seeking help from a professional mechanic or dealership with experience in automotive electronics. By following these steps, you should be able to identify the cause of the U1907 code and take appropriate action to resolve the communication failure.