U1696 – Module Communication Failure

The ODBII code U1696 indicates a “Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules.

The severity of ODBII code U1696 is generally considered moderate.

Common Causes For: U1695 Lost Communication with Body Control Module.

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

Common misdiagnosis for U1696 U1696: “Module Communication Failure”

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

Common Troubleshooting Steps

The OBD-II code U1696 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 ground connections, as poor grounding can lead to communication issues.
• Check Power Supply:
• Ensure that the affected module is receiving the proper voltage and ground. Use a multimeter to check the power supply to the module.
• If the module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wires.
• Test the Module:
• If possible, test the affected module by swapping it with a known good module (if applicable) to see if the problem persists.
• Some modules may have self-diagnostic capabilities; consult the service manual for specific testing procedures.
• Check for Communication:
• Use a scan tool to check if the affected module is communicating with other modules. If it is not, there may be a fault within the module itself or the communication network.
• You can also use a scope or a scan tool to monitor the data bus for activity.
• Inspect the CAN Bus:
• If your vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. Look for short circuits, open circuits, or interference.
• Use a multimeter or oscilloscope to check the CAN bus signals for proper voltage levels and waveforms.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the manufacturer for any available updates for the vehicle’s control modules.
• Clear Codes and Test Drive:
• After performing any repairs or adjustments, 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 U1696 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 the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these steps, you should be able to identify and resolve the underlying issue causing the U1696 code.