U1890 – Module Communication Failure

The ODBII code U1890 indicates a “Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules.

The severity of ODBII code U1890 is moderate.

Common Causes For: U1889 U1889: “Data Bus Communication Failure”

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Intermittent communication issues
• Corroded or damaged pins in connectors
• Software or firmware issues
• Low battery voltage or power supply problems
• Electrical interference from other components

Common misdiagnosis for U1890 U1890: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Power supply problems
• Grounding issues
• Intermittent communication issues
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U1890 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between various control modules in the vehicle. 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 other trouble codes that may be present. Sometimes, multiple codes can provide clues about the underlying issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the modules, as these can be prone to wear and tear.
• Check Power and Ground:
• Ensure that the affected module(s) are receiving proper power and ground. Use a multimeter to check voltage and ground continuity.
• If the module is not receiving power, trace the circuit back to the fuse box and check for blown fuses or damaged wiring.
• Test the Affected Module:
• If possible, test the affected module to see if it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one.
• If the module is faulty, it may need to be repaired or replaced.
• Check for Communication Issues:
• Use a scan tool to check if other modules in the network are communicating properly. If other modules are also showing communication errors, it may indicate a network issue.
• Look for issues with the CAN (Controller Area Network) bus, as this is often the communication protocol used between modules.
• Inspect the CAN Bus:
• Check the integrity of the CAN bus wiring. Look for shorts, opens, or high resistance in the bus lines.
• Use an oscilloscope to monitor the CAN bus signals if you have access to one. This can help identify communication problems.
• Reset the Modules:
• Sometimes, simply resetting the modules can resolve communication issues. Disconnect the battery for a few minutes, then reconnect it and see if the code returns.
• Software Updates:
• Check if there are any software updates available for the vehicle’s control modules. Sometimes, manufacturers release updates to fix communication issues.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented known issues and solutions for communication failures.
• Professional Diagnosis:
• If the issue persists after performing the above steps, it may be necessary to seek the help of a professional technician who has experience with the specific vehicle and access to advanced diagnostic tools. By following these steps, you should be able to identify and resolve the underlying cause of the U1890 code.