U1515 – Vehicle Network Communication Error

The ODBII code U1515 indicates a “Vehicle Network Communication Error,” which means there is a problem with the communication between various control modules in the vehicle’s network.

The severity of ODBII code U1515 is moderate.

Common Causes For: U1514 U1514: Transmission Control Module Communication Error

• Faulty wiring or connectors in the communication network.
• Malfunctioning control modules.
• Corrupted software in one or more modules.
• Poor ground connections.
• Intermittent electrical issues.
• Faulty or damaged CAN bus.
• Issues with the vehicle’s battery or charging system.

Common misdiagnosis for U1515 U1515: “Vehicle Network Communication Error”

• Faulty ABS module
• Defective engine control module (ECM)
• Malfunctioning transmission control module (TCM)
• Wiring issues or shorts in the communication lines
• Bad ground connections
• Faulty body control module (BCM)
• Incorrectly installed aftermarket accessories
• Corrupted software or firmware in modules
• Battery or charging system problems
• Intermittent connection issues in connectors or terminals

Common Troubleshooting Steps

The OBD-II code U1515 indicates a “Vehicle Network Communication Error,” which typically points to 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, U1515 may be accompanied by other codes that can provide more context about the issue.
• Inspect Wiring and Connectors: **Visual Inspection: Check the wiring and connectors related to the communication network (CAN bus). Look for signs of damage, corrosion, or loose connections.
• **Repair or Replace: If any damaged wires or connectors are found, repair or replace them as necessary.
• Check for Short Circuits: Use a multimeter to check for short circuits in the wiring harness. Ensure that there are no unintended connections between wires that could disrupt communication.
• Test the Modules: **Module Functionality: Verify that all modules on the network are functioning correctly. If a specific module is malfunctioning, it may disrupt communication.
• **Reprogram or Replace: If a module is found to be faulty, it may need to be reprogrammed or replaced.
• Inspect the CAN Bus: **Termination Resistors: Ensure that the CAN bus has the correct termination resistors in place. Typically, there should be a 120-ohm resistor at each end of the bus.
• **Signal Integrity: Use an oscilloscope to check the signal integrity on the CAN bus. Look for any irregularities in the signal that could indicate a problem.
• 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.
• Battery and Ground Connections: Ensure that the vehicle’s battery is in good condition and that all ground connections are secure. Poor power supply or grounding can lead to communication errors.
• Clear Codes and Test Drive: After performing any repairs or checks, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears.
• Consult Technical Service Bulletins (TSBs): Check for any manufacturer-specific TSBs related to U1515 or communication issues. There may be known fixes or updates available.
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis and repair. By following these steps, you can systematically identify and resolve the underlying issues causing the U1515 code.