U2673 – Vehicle Communication Bus Malfunction

The ODBII code U2673 indicates a malfunction in the vehicle communication bus, which affects the ability of various electronic control units (ECUs) to communicate with each other.

The severity of ODBII code U2673 is moderate.

Common Causes For: U2672 Invalid Data Received from Vehicle Dynamics Control Module.

• Faulty OBD-II connector
• Damaged wiring or connectors in the communication bus
• Malfunctioning control modules
• Poor ground connections
• Corroded or loose terminals
• Software issues or bugs in the control modules
• Interference from aftermarket devices
• Low battery voltage or power supply issues

Common misdiagnosis for U2673 U2673: “Vehicle Communication Bus Malfunction”

• Faulty ECM (Engine Control Module)
• Defective BCM (Body Control Module)
• Wiring issues or shorts in the communication bus
• Bad connectors or terminals
• Faulty sensors or actuators
• Issues with the CAN (Controller Area Network) system
• Power supply problems to modules
• Software or firmware issues in control modules

Common Troubleshooting Steps

The OBD-II code U2673 indicates a “Vehicle Communication Bus Malfunction.” This code typically points to issues with the communication between various control modules in the vehicle. 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. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the communication bus (CAN bus). Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors on the control modules, as well as any junction points in the wiring harness.
• Test the Communication Bus:
• Use a multimeter or an oscilloscope to check the voltage levels on the CAN bus wires. The typical voltage levels should be around 2.5V to 3.5V when the vehicle is on.
• Check for short circuits or open circuits in the communication lines.
• Check Control Modules:
• Ensure that all control modules are functioning properly. A malfunctioning module can disrupt communication on the bus.
• If possible, perform a software update or reset on the control modules.
• Inspect Ground Connections:
• Ensure that all ground connections related to the control modules and communication bus are secure and free of corrosion.
• Look for Interference:
• Check for any aftermarket devices or modifications that may interfere with the vehicle’s communication systems, such as alarms, remote starters, or audio systems.
• Perform a Network Test:
• Some advanced scan tools can perform a network test to check the integrity of the communication bus and identify any faulty modules.
• Check for Battery Voltage Issues:
• Ensure that the vehicle’s battery is in good condition and that the voltage is within the normal range. Low voltage can cause communication issues.
• Clear Codes and Test Drive:
• After performing the above checks and repairs, clear the trouble codes 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 related to the communication bus and any manufacturer-specific troubleshooting steps. If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific make and model of your vehicle. They may have access to specialized diagnostic tools and resources to further investigate the problem.