U2190 – Vehicle Communication Bus Malfunction

The ODBII code U2190 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 U2190 is moderate.

Common Causes For: U2189 U2189: “Module Communication Failure”

• 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 weak battery
• Faulty or incompatible scan tool
• Issues with the vehicle’s power distribution system

Common misdiagnosis for U2190 U2190: “Vehicle Communication Bus Malfunction”

• Faulty OBDII connector
• Bad ground connections
• Defective ECM (Engine Control Module)
• Faulty wiring or harness issues
• Malfunctioning sensors
• Issues with the CAN bus system
• Problems with the powertrain control module (PCM)
• Incorrectly installed aftermarket accessories
• Software glitches or outdated firmware
• Battery or charging system problems

Common Troubleshooting Steps

The OBD-II code U2190 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 Controller Area Network (CAN) bus. 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 which module is having communication issues.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors related to the CAN bus. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors on the Engine Control Module (ECM), Transmission Control Module (TCM), and any 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 (ECM, TCM, etc.) for proper operation. A malfunctioning module can cause communication issues.
• If you have access to a scan tool that can communicate with individual modules, check if they respond correctly.
• 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 and ground connections. Poor power supply or grounding can lead to communication issues.
• Update or Reprogram Modules: In some cases, a software update or reprogramming of the affected modules may be necessary. Check with the manufacturer for any available updates.
• 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 a Professional: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with vehicle communication systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issues causing the U2190 code.