U2248 – Vehicle Communication Bus Malfunction

The ODBII code U2248: Vehicle Communication Bus Malfunction indicates a problem with the communication between various control modules in the vehicle, often related to the CAN (Controller Area Network) bus system.

The severity of ODBII code U2248 is generally considered moderate.

Common Causes For: U2247 U2247: Vehicle Communication Bus Malfunction

• 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
• Faulty or incompatible diagnostic tools
• Issues with the vehicle’s CAN bus system

Common misdiagnosis for U2248 U2248: Vehicle Communication Bus Malfunction

• Faulty OBDII connector
• Bad ground connections
• Defective ECM (Engine Control Module)
• Malfunctioning BCM (Body Control Module)
• Wiring issues or shorts in the communication lines
• Faulty sensors or actuators
• Software glitches or outdated firmware
• Issues with the CAN bus system
• Problems with other control modules
• Battery or power supply issues

Common Troubleshooting Steps

The OBD-II code U2248 indicates a “Vehicle Communication Bus Malfunction.” This code typically points to issues with the communication between various modules in the vehicle, often related to the CAN (Controller Area Network) bus system. Here are some common troubleshooting steps to diagnose and resolve the 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 CAN bus. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors at the ECM (Engine Control Module) and other modules that communicate over the bus.
• Check for Short Circuits or Open Circuits: Use a multimeter to check for continuity in the CAN bus wiring. Look for any short circuits or open circuits that could disrupt communication.
• Test the Modules: If possible, test the individual modules (like the ECM, BCM, ABS, etc.) for proper operation. A malfunctioning module can cause communication issues.
• If you have access to a scan tool that can communicate with all modules, check if you can read data from them.
• Inspect the CAN Bus Termination Resistors: Ensure that the CAN bus has the correct termination resistors (typically 120 ohms) at both ends of the bus. A missing or faulty resistor can lead to communication problems.
• Check for Interference: Look for any aftermarket devices or modifications that may interfere with the vehicle’s communication systems, such as alarms, remote starters, or audio systems.
• Battery and Ground Connections: Check the vehicle’s battery voltage and ensure that all ground connections are clean and secure. Poor power or ground can lead to communication issues.
• Perform a Network Test: If you have access to advanced diagnostic tools, perform a network test to check the integrity of the CAN bus communication.
• Clear Codes and Test Drive: After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs): Check for any manufacturer-specific TSBs related to the U2248 code or communication issues for your vehicle make and model.1
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who specializes in automotive electronics. By following these troubleshooting steps, you can systematically identify and resolve the underlying issues causing the U2248 code.