U1330 – Network Communication Fault in Control Modules

The ODBII code U1330 indicates a communication fault between control modules in a vehicle’s network, suggesting that one or more modules are not properly communicating with each other.

The severity of ODBII code U1330 is moderate.

Common Causes For: U1328 U1328: “Control Module Communication Fault”

• Faulty wiring or connectors
• Corroded or damaged terminals
• Failed control module
• Poor ground connections
• Intermittent communication issues
• Software glitches or outdated firmware
• Faulty CAN bus or LIN bus
• Electrical interference
• Low battery voltage or power supply issues
• Improperly installed aftermarket accessories

Common misdiagnosis for U1330 U1330: “Network Communication Fault in Control Modules”

• Faulty wiring or connectors
• Defective control modules
• Battery or charging system issues
• Grounding problems
• Software or firmware issues
• Communication protocol errors
• Sensor malfunctions
• Intermittent faults in the network
• Corrupted data or signals
• Electrical interference or noise

Common Troubleshooting Steps

The OBD-II code U1330 indicates a “Network Communication Fault in Control Modules.” This code typically points to issues with the communication between various control modules in the vehicle’s network, such as the CAN (Controller Area Network) bus. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing related codes can help pinpoint the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring harnesses and connectors associated with the control modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors for the modules that are part of the communication network.
• Test the Control Modules: If possible, test the control modules involved in the communication network. This may involve checking for proper voltage and ground at the connectors.
• If you have access to a known good module, you can swap it in to see if the issue persists.
• Check the CAN Bus: Use a multimeter or an oscilloscope to check the CAN bus signals. You should see a specific voltage level (typically around 2.5V) when the vehicle is on.
• Look for any short circuits or open circuits in the CAN bus wiring.
• Inspect for Interference: Check for any aftermarket devices or modifications that may interfere with the vehicle’s communication network, such as alarms, stereo systems, or other electronic devices.
• Clear Codes and Test Drive: After performing inspections 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.
• Check for Software Updates: Sometimes, control modules may require software updates to resolve communication issues. Check with the manufacturer for any available updates.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues related to U1330.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience with the specific vehicle.
• Replace Faulty Components: If a specific control module is identified as faulty, it may need to be replaced. Ensure that the replacement module is compatible with the vehicle. By following these troubleshooting steps, you can systematically identify and resolve the underlying issue causing the U1330 code.