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U code network High severity

U1658 Communication Network Malfunction

The OBD2 code U1658 indicates a communication network malfunction, typically related to a failure in the communication between various control modules in the vehicle's network

Definition

The OBD2 code U1658 indicates a communication network malfunction, typically related to a failure in the communication between various control modules in the vehicle's network

Common causes

  • 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 misdiagnoses

  • 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)

Troubleshooting steps

  1. 1. 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

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to the ground connections, as poor grounding can lead to communication issues

  5. 5. Check for Module Functionality

  6. 6. Determine if the affected modules are functioning properly. This may involve testing individual modules or using a scan tool to check their status

  7. 7. If a specific module is not responding, it may need to be replaced or reprogrammed

  8. 8. Verify Power Supply

  9. 9. Ensure that all modules have the proper power supply. Check fuses related to the communication network and replace any blown fuses

  10. 10. Measure voltage at the module connectors to confirm they are receiving the correct voltage

  11. 11. Inspect the CAN Bus

  12. 12. 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

  13. 13. Use an oscilloscope to check the CAN signals if you have the necessary tools and expertise

  14. 14. Perform a Network Test

  15. 15. 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

  16. 16. Reset the Codes

  17. 17. 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

  18. 18. Check for Software Updates

  19. 19. 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

  20. 20. Consult Technical Service Bulletins (TSBs)

  21. 21. 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

  22. 22. Seek Professional Help

  23. 23. 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