U2848 – Control Module Communication Bus Fault

The ODBII code U2848: Control Module Communication Bus Fault indicates a communication issue between control modules in the vehicle, suggesting that one or more modules are not properly communicating over the vehicle’s data bus.

The severity of ODBII code U2848 is generally considered moderate to severe.

Common Causes For: U2847 U2847: Vehicle Communication Bus Malfunction

• Faulty control module
• Damaged wiring or connectors
• Poor ground connections
• Corroded terminals
• Intermittent electrical connections
• Software issues or bugs
• Faulty communication bus (CAN bus) components
• Low battery voltage or power supply issues

Common misdiagnosis for U2848 U2848: Control Module Communication Bus Fault

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Faulty sensors
• Battery or power supply issues
• Intermittent connection problems
• Incorrectly installed aftermarket components

Common Troubleshooting Steps

The OBD-II code U2848 indicates a “Control Module Communication Bus Fault.” This code typically points to a communication issue 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 related trouble codes. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors associated with the control modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the affected modules.
• Check Power and Ground: Ensure that the control modules have proper power and ground connections. Use a multimeter to check voltage and ground continuity.
• Verify that the fuses related to the control modules are intact.
• Test the Communication Bus: Use a scan tool to monitor the communication on the CAN (Controller Area Network) bus. Check for any irregularities in data transmission.
• If possible, use an oscilloscope to analyze the signal on the bus for any abnormalities.
• Isolate Modules: If you suspect a specific module is causing the issue, you can try disconnecting it and see if the code persists. This can help isolate the faulty module.
• Reconnect modules one at a time to identify which one is causing the communication fault.
• Check for Software Updates: Sometimes, control modules may require software updates to resolve communication issues. Check with the manufacturer for any available updates.
• Inspect for Interference: Look for any aftermarket devices or modifications that may interfere with the communication bus, such as alarms, remote starters, or other electronic devices.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the control modules. Reconnect and see if the code reappears.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues related to communication faults.
• Replace Faulty Modules: If a specific control module is determined to be faulty after testing, it may need to be replaced. Ensure that the replacement module is compatible with the vehicle.1
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing communication issues.Conclusion Troubleshooting a U2848 code can be complex due to the nature of vehicle communication systems. Following these steps systematically can help identify and resolve the underlying issue. Always refer to the vehicle’s service manual for specific procedures and specifications.