U1912 – Module Communication Failure

The ODBII code U1912 indicates a “Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules, often due to a wiring issue, a faulty module, or a network problem.

The severity of ODBII code U1912 is moderate.

Common Causes For: U1911 CAN Bus Communication Error – Missing Message from the Instrument Cluster.

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Corroded or damaged pins in connectors
• Intermittent electrical issues
• Software or firmware issues in the module
• Low battery voltage or power supply issues
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U1912 U1912: “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 U1912 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. 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 more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module(s). 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 has a proper power supply and ground connection. Use a multimeter to check for voltage at the module’s power and ground pins.
• If there is no power or ground, trace the wiring back to the source to identify any breaks or shorts.
• Test the Module:
• If possible, test the affected module to ensure it is functioning correctly. This may involve swapping it with a known good module or using specialized diagnostic equipment.
• Some modules may have self-diagnostic capabilities that can provide additional information.
• Check for Communication:
• Use a scan tool to check if the affected module is communicating with other modules in the network. If it is not responding, it may be faulty.
• You can also use a scope or a scan tool with live data capabilities to monitor communication signals on the CAN bus.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus, check for issues on the bus itself. Look for short circuits, open circuits, or excessive resistance.
• You can use a multimeter to measure the resistance between the CAN high and CAN low wires. The resistance should typically be around 60 ohms.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update for the affected module. Check with the manufacturer for any available updates.
• Clear Codes and Test Drive:
• After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs):
• Check for any TSBs related to the U1912 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues that can help in troubleshooting.
• Seek Professional Help:
• If you are unable to resolve the issue after performing these steps, it may be best to consult a professional mechanic or technician who has experience with your vehicle’s make and model. By following these steps, you should be able to identify and resolve the underlying issue causing the U1912 code.