U1658 – Communication Network Malfunction
The ODBII code U1658 indicates a communication network malfunction, typically related to a failure in the communication between various control modules in the vehicle’s network.
The severity of ODBII code **U1658: Communication Network Malfunction** is generally considered moderate to severe.
Common Causes For: U1645: Body Control Module Communication Failure
- Faulty wiring or connectors
- Malfunctioning control modules
- Corrupted software or firmware
- Poor ground connections
- Intermittent electrical connections
- Short circuits in the communication lines
- Faulty or damaged sensors
- Issues with the vehicle’s battery or charging system
- Aftermarket modifications or installations affecting communication
- Environmental factors (moisture, corrosion) affecting connections
Common misdiagnosis for U1658: Communication Network Malfunction
- Faulty ABS module
- Defective body control module (BCM)
- Malfunctioning engine control module (ECM)
- Wiring issues or shorts in the communication lines
- Faulty sensors or actuators
- Bad ground connections
- Incorrectly programmed modules
- Failed or weak battery
- Corroded connectors or terminals
- Issues with the powertrain control module (PCM)
Common Troubleshooting Steps
The OBD-II code **U1658: Communication Network Malfunction** indicates a problem with the communication between various modules in the vehicle’s network. This can be caused by a variety of issues, including wiring problems, module failures, or issues with the vehicle’s communication protocols. Here are some common troubleshooting steps to diagnose and resolve this code:
- Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context about the issue and help identify which module is having communication problems.
- Inspect Wiring and Connectors:
- Visually inspect the wiring and connectors associated with the affected modules. 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 for Module Functionality:
- Determine if the affected modules are functioning properly. This may involve testing individual modules or using a scan tool to check their status.
- If a specific module is not responding, it may need to be replaced or reprogrammed.
- Verify Power Supply:
- Ensure that all modules have the proper power supply. Check fuses related to the communication network and replace any blown fuses.
- Measure voltage at the module connectors to confirm they are receiving the correct voltage.
- Inspect the CAN Bus:
- If your vehicle uses a Controller Area Network (CAN) bus, check the integrity of the bus. Look for short circuits, open circuits, or any other issues that could disrupt communication.
- Use an oscilloscope to check the CAN signals if you have the necessary tools and expertise.
- Perform a Network Test:
- Some advanced scan tools can perform a network test to check the communication between modules. This can help identify which module is not communicating properly.
- Reset the Codes:
- 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:
- In some cases, a software update may be available for the vehicle’s modules. Check with the manufacturer or a dealership to see if any updates are needed.
- Consult Technical Service Bulletins (TSBs):
- Look for any TSBs related to the U1658 code for your specific vehicle make and model. Manufacturers may have identified common issues and provided solutions.
- 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 automotive electronics and communication systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issues causing the U1658 code.