U1573 – Module Communication Failure

The ODBII code U1573 indicates a communication failure between modules in the vehicle’s network, suggesting that one or more electronic control units (ECUs) are not able to communicate properly with each other.

The severity of ODBII code U1573 is generally considered moderate.

Common Causes For: U1572 U1572: “Vehicle Communication Network Malfunction”

• Faulty wiring or connectors
• Malfunctioning control module
• Corrupted software or firmware
• Poor ground connections
• Interference from aftermarket devices
• Low battery voltage
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U1573 U1573: “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 U1573 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between various 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, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to ground connections, as poor grounding can lead to communication issues.
• Check Module 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 powered correctly, trace the wiring back to the power source.
• Test the Affected Module:
• If possible, test the module itself to ensure it is functioning correctly. This may involve bench testing or swapping with a known good module.
• Some modules may have self-diagnostic capabilities that can provide additional information.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. Look for short circuits, open circuits, or other faults in the wiring.
• Use an oscilloscope or a CAN bus analyzer to monitor the communication signals on the bus.
• Check for Interference:
• Look for any aftermarket devices or modifications that may be interfering with the vehicle’s communication network. This includes alarms, stereo systems, or other electronic devices.
• Reset the Modules:
• Sometimes, simply resetting the affected module or the entire vehicle’s network can resolve communication issues. This can be done by disconnecting the battery for a few minutes or using a scan tool to clear codes.
• Update Software/Firmware:
• Check if there are any software or firmware updates available for the affected module. Manufacturers may release updates to fix known 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 solutions for common communication issues.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose complex communication problems. By following these steps, you can systematically identify and address the root cause of the U1573 code.