U1349 – Network Communication Error

The ODBII code U1349 indicates a network communication error, typically related to a malfunction in the vehicle’s communication network, affecting the exchange of data between control modules.

The severity of ODBII code U1349: Network Communication Error is generally considered moderate to severe.

Common Causes For: 1. U1342: Module Communication Failure

• Faulty wiring or connectors in the communication network.
• Malfunctioning control modules.
• Poor ground connections.
• Interference from aftermarket devices.
• Corroded or damaged pins in connectors.
• Software issues or bugs in the control modules.
• Low battery voltage or power supply issues.

Common misdiagnosis for 1. U1349: Network Communication Error

• Faulty OBDII connector
• Bad ground connections
• Defective ECM (Engine Control Module)
• Wiring issues or shorts
• Faulty sensors
• Corrupted software or firmware
• Issues with other control modules
• Battery or power supply problems

Common Troubleshooting Steps

The OBD-II code U1349 indicates a “Network Communication Error,” which typically suggests that there is a problem with the 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 additional trouble codes. Sometimes, U1349 may be accompanied by other codes that can provide more context about the issue.
• Inspect Wiring and Connectors: Examine the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections. Pay special attention to the CAN (Controller Area Network) bus wiring.
• Check Battery Voltage: Ensure that the vehicle’s battery is fully charged and that the voltage is within the normal range (typically 12.4 to 12.6 volts when the engine is off). Low voltage can cause communication issues.
• Inspect Ground Connections: Verify that all ground connections are secure and free of corrosion. Poor grounding can lead to communication errors.
• Test Modules: If you suspect a specific module is causing the issue, you can test it by checking for proper operation or by swapping it with a known good module if possible.
• Check for Short Circuits: Use a multimeter to check for short circuits in the wiring harnesses. A short can disrupt communication between modules.
• Scan for Communication Issues: Use a professional-grade scan tool to check for communication between modules. Some tools can perform a network test to identify which module is not responding.
• Update Software/Firmware: Check if there are any software or firmware updates available for the vehicle’s modules. Sometimes, communication issues can be resolved with an update.
• Clear Codes and Test Drive: After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code reappears.
• Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures related to the U1349 code and the vehicle’s communication network. 1
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who specializes in automotive electronics and diagnostics. By following these steps, you can systematically identify and resolve the underlying cause of the U1349 code.