WOMS
U code network Medium severity

U2190 U2190: "Vehicle Communication Bus Malfunction

The OBD2 code U2190 indicates a malfunction in the vehicle communication bus, which affects the ability of various electronic control units (ECUs) to communicate with each other

Definition

The OBD2 code U2190 indicates a malfunction in the vehicle communication bus, which affects the ability of various electronic control units (ECUs) to communicate with each other

Common causes

  • Faulty OBD-II connector
  • Damaged wiring or connectors in the communication bus
  • Malfunctioning control modules
  • Poor ground connections
  • Corroded or loose terminals
  • Software issues or bugs in the control modules
  • Interference from aftermarket devices
  • Low battery voltage or weak battery
  • Faulty or incompatible scan tool
  • Issues with the vehicle's power distribution system

Common misdiagnoses

  • Faulty OBDII connector
  • Bad ground connections
  • Defective ECM (Engine Control Module)
  • Faulty wiring or harness issues
  • Malfunctioning sensors
  • Issues with the CAN bus system
  • Problems with the powertrain control module (PCM)
  • Incorrectly installed aftermarket accessories
  • Software glitches or outdated firmware
  • Battery or charging system problems

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Other codes may provide more context or indicate which module is having communication issues

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors related to the CAN bus. Look for signs of damage, corrosion, or loose connections

  3. 3. Pay special attention to the connectors on the Engine Control Module (ECM), Transmission Control Module (TCM), and any other modules that communicate over the bus

  4. 4. Check for Short Circuits or Open Circuits

    Use a multimeter to check for continuity in the CAN bus wiring. Look for any short circuits or open circuits that could disrupt communication

  5. 5. Test the Modules

    If possible, test the individual modules (ECM, TCM, etc.) for proper operation. A malfunctioning module can cause communication issues

  6. 6. If you have access to a scan tool that can communicate with individual modules, check if they respond correctly

  7. 7. Inspect the CAN Bus Termination Resistors

    Ensure that the CAN bus has the correct termination resistors (typically 120 ohms) at both ends of the bus. A missing or faulty resistor can lead to communication problems

  8. 8. Check for Interference

    Look for any aftermarket devices or modifications that may interfere with the vehicle's communication systems, such as alarms, remote starters, or audio systems

  9. 9. Battery and Ground Connections

    Check the vehicle's battery and ground connections. Poor power supply or grounding can lead to communication issues

  10. 10. Update or Reprogram Modules

    In some cases, a software update or reprogramming of the affected modules may be necessary. Check with the manufacturer for any available updates

  11. 11. 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 returns

  12. 12. Consult a Professional

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with vehicle communication systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issues causing the U2190 code