U2916 – Vehicle Communication Bus Malfunction

The ODBII code U2916 indicates a malfunction in the vehicle communication bus, which affects the communication between various control modules in the vehicle.

The severity of ODBII code U2916 is generally considered moderate.

Common Causes For: U2915 Vehicle Communication Bus Malfunction

• Faulty wiring or connectors in the communication bus
• Malfunctioning control modules
• Corroded or damaged pins in connectors
• Short circuits in the communication lines
• Interference from aftermarket devices
• Software issues or bugs in the control modules
• Poor ground connections
• Faulty or damaged OBD-II port
• Issues with the vehicle’s battery or charging system

Common misdiagnosis for U2916 Vehicle Communication Bus Malfunction

• Faulty Engine Control Module (ECM)
• Defective Body Control Module (BCM)
• Bad wiring or connectors
• Malfunctioning sensors
• Issues with the powertrain control module (PCM)
• Battery or charging system problems
• Incorrectly diagnosed transmission issues
• Faulty diagnostic tools or software errors

Common Troubleshooting Steps

The OBD-II code U2916 indicates a “Vehicle Communication Bus Malfunction.” This code typically points to issues with the communication between various modules in the vehicle, which can affect the overall functionality of the vehicle’s systems. 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 modules that are part of the communication network.
• Check for Short Circuits or Open Circuits:
• Use a multimeter to check for continuity in the communication lines. Look for any short circuits or open circuits that could disrupt communication.
• Test the resistance of the communication lines to ensure they are within specifications.
• Inspect Modules:
• Identify the modules that are part of the communication network and check for any signs of failure or malfunction.
• If possible, perform a reset or reprogramming of the affected modules.
• Test the Communication Bus:
• Use a scan tool that can monitor live data to check if the modules are communicating properly. Look for any modules that are not responding.
• If you have access to a CAN bus analyzer, you can use it to monitor the bus for errors.
• Check Power and Ground:
• Ensure that all modules on the communication bus have proper power and ground connections. A lack of power or a poor ground can cause communication issues.
• Look for Environmental Factors:
• Check for any environmental factors that could affect the communication bus, such as water intrusion or exposure to extreme temperatures.
• Perform a Hard Reset:
• Disconnect the vehicle’s battery for a few minutes to reset the vehicle’s systems. Reconnect the battery and see if the code reappears.
• Update Software/Firmware:
• Check if there are any software or firmware updates available for the vehicle’s modules. Sometimes, updating the software can resolve communication issues.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues related to communication bus malfunctions. 1
• Seek Professional Help:
• If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific vehicle and its communication systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U2916 code.