U1992 – Inter-Module Communication Failure

The ODBII code U1992 indicates a failure in communication between modules in a vehicle’s network, suggesting that one or more electronic control units (ECUs) are unable to exchange data properly.

The severity of ODBII code U1992 is generally considered moderate.

Common Causes For: U1991 U1991: “Inter-Module Communication Failure”

• Faulty wiring or connectors
• Malfunctioning control modules
• Poor ground connections
• Corroded or damaged connectors
• Software issues or incompatibility
• Low battery voltage or weak battery
• Interference from aftermarket devices
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U1992 U1992: “Inter-Module Communication Failure”

• Faulty wiring or connectors
• Defective control modules
• Software issues or updates needed
• Battery or power supply problems
• Grounding issues
• Corrupted data or communication protocols
• Sensor malfunctions
• Interference from aftermarket devices

Common Troubleshooting Steps

The OBD-II code U1992 indicates an “Inter-Module Communication Failure,” which typically means that there is a problem with the communication between different modules in the vehicle’s network. 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, U-codes can be related to other issues that may provide more context.
• Inspect Wiring and Connectors: Examine the wiring and connectors associated with the modules involved in the communication network. Look for signs of damage, corrosion, or loose connections. Pay special attention to the ground connections.
• Check Module Functionality: Identify the modules that are supposed to communicate with each other. Ensure that they are functioning properly. This may involve checking for power and ground at the modules.
• Verify Network Integrity: Use a multimeter to check the resistance of the communication lines (CAN bus, LIN bus, etc.) to ensure there are no shorts or open circuits. The resistance should typically be around 60 ohms for a CAN bus.
• Inspect for Interference: Look for any aftermarket devices or modifications that may interfere with the vehicle’s communication network. This includes things like aftermarket radios, alarms, or other electronic devices.
• Perform a Network Scan: Use a professional-grade scan tool to perform a network scan. This can help identify which module is not responding or communicating properly.
• Check for Software Updates: Sometimes, communication issues can be resolved with a software update for the affected modules. Check with the manufacturer for any available updates.
• Reset the Modules: Disconnect the battery for a few minutes to reset the modules. Reconnect and see if the code reappears.
• Test Individual Modules: If you suspect a specific module is causing the issue, you may need to test or replace it. This can involve bench testing or swapping with a known good module.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the U1992 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues. 1
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with automotive electronics and communication systems. By following these steps, you should be able to identify and resolve the underlying issue causing the U1992 code.