WOMS
U code network High severity

U2529 refers to a communication issue between control modules, specifically indicating a problem with the "High Speed CAN Bus

The OBD2 code U2529 indicates a communication issue between control modules due to a malfunction in the High Speed CAN Bus, which may affect data transmission and functionality of connected systems

Definition

The OBD2 code U2529 indicates a communication issue between control modules due to a malfunction in the High Speed CAN Bus, which may affect data transmission and functionality of connected systems

Common causes

  • Faulty wiring or connectors in the High Speed CAN Bus circuit
  • Short circuits or open circuits in the CAN Bus wiring
  • Malfunctioning control modules (e.g., ECM, TCM)
  • Corroded or damaged connectors
  • Interference from aftermarket devices or modifications
  • Poor ground connections
  • Software issues or bugs in the control modules
  • Faulty termination resistors in the CAN Bus network

Common misdiagnoses

  • Faulty control module
  • Bad wiring or connectors
  • Power supply issues
  • Grounding problems
  • Intermittent short circuits
  • Faulty sensors
  • Software glitches or updates needed
  • Incorrectly installed aftermarket accessories
  • Corroded terminals
  • Issues with the low-speed CAN bus

Troubleshooting steps

  1. 1. Check for Other Codes

    Scan the vehicle for any additional trouble codes. Other codes may provide more context or indicate which module is having issues

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harnesses and connectors associated with the High-Speed CAN bus for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or pushed back

  4. 4. Test the CAN Bus Voltage

    Use a multimeter to measure the voltage on the CAN High and CAN Low wires. The typical voltage levels should be around 2.5V when the bus is idle

  5. 5. Check for proper voltage levels while the vehicle is running

  6. 6. Check for Short Circuits

    Inspect the CAN bus wiring for any short circuits to ground or to each other. This can cause communication failures

  7. 7. Disconnect Modules

    If multiple modules are connected to the CAN bus, disconnect them one at a time to isolate the faulty module. After disconnecting a module, clear the codes and see if the U2529 code returns

  8. 8. Test Individual Modules

    If a specific module is suspected, test it for proper operation. This may involve checking its power and ground connections, as well as its ability to communicate on the CAN bus

  9. 9. Check for Interference

    Ensure that there are no aftermarket devices (like alarms, radios, etc.) that could be interfering with the CAN bus communication

  10. 10. Use a CAN Bus Scanner

    If available, use a specialized CAN bus scanner to monitor the communication on the bus. This can help identify if specific messages are missing or if there are communication errors

  11. 11. Inspect the Ground Connections

    Ensure that all ground connections for the control modules are secure and free of corrosion. Poor grounding can lead to communication issues

  12. 12. Update or Reprogram Modules

    In some cases, a software update or reprogramming of the affected control module(s) may be necessary to resolve communication issues.1

  13. 13. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician with experience in automotive electronics and CAN bus systems. By following these steps, you should be able to identify and resolve the communication issue indicated by the U2529 code