WOMS
U code network Medium severity

U0017 Medium Speed CAN Communication Bus (-) High

The OBD2 code U0017 indicates a fault in the medium speed CAN communication bus, specifically a high signal issue, which suggests a problem with data transmission between modules in the vehicle's network

Definition

The OBD2 code U0017 indicates a fault in the medium speed CAN communication bus, specifically a high signal issue, which suggests a problem with data transmission between modules in the vehicle's network

Common causes

  • Faulty CAN bus wiring or connectors
  • Short circuit in the CAN bus
  • Open circuit in the CAN bus
  • Faulty or damaged CAN bus module
  • Interference from other electrical components
  • Poor ground connection
  • Faulty or incompatible aftermarket accessories
  • Software or firmware issues in the control modules

Common misdiagnoses

  • Faulty CAN bus wiring
  • Defective CAN bus module
  • Faulty engine control unit (ECU)
  • Bad ground connections
  • Malfunctioning sensors
  • Power supply issues
  • Incorrectly configured or programmed modules
  • Intermittent electrical connections

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context about the issue and help identify if other systems are affected

  2. 2. Inspect Wiring and Connectors

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

  3. 3. Repair or Replace

    If any damaged wires or connectors are found, repair or replace them as necessary

  4. 4. Check for Short Circuits

    Use a multimeter to check for short circuits in the CAN bus wiring. A short to power or ground can cause the signal to be high

  5. 5. Disconnect the battery before performing any tests to avoid damage to the vehicle's electronics

  6. 6. Test the CAN Bus Signal

    Use an oscilloscope or a CAN bus diagnostic tool to monitor the CAN bus signals. Check for proper voltage levels and signal integrity

  7. 7. Compare the readings with manufacturer specifications to determine if the signals are within acceptable ranges

  8. 8. Inspect Modules on the CAN Bus

    Identify all modules connected to the Medium Speed CAN bus. Check for any malfunctioning modules that may be causing communication issues

  9. 9. Disconnect each module one at a time to see if the code clears or if the communication improves

  10. 10. Check for Ground Issues

    Ensure that all ground connections related to the CAN bus are secure and free of corrosion. Poor grounding can lead to communication problems

  11. 11. Look for Interference

    Check for any aftermarket devices or modifications that may interfere with the CAN bus communication. This includes alarms, stereo systems, or other electronic devices

  12. 12. 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

  13. 13. Clear Codes and Test Drive

    After performing the above checks 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

  14. 14. Consult a Professional

    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 troubleshooting steps, you can systematically identify and resolve the issue related to the U0017 code