U0017 Guide to Diagnosing
Medium Speed CAN Communication Bus (-) High
The U0017 OBD-II code refers to a communication issue on the Medium-Speed CAN (Controller Area Network) Bus in a vehicle’s electronic control systems. This error code specifically indicates that the High signal on the Medium-Speed CAN bus is reporting a high voltage or is stuck in a high state, which can lead to malfunctioning of critical systems.
This code signals that the Medium-Speed CAN Bus is experiencing a problem, where the negative signal (or ground reference) is reading as too high (greater than expected).
Symptoms:
Loss of Communication, Illuminated Warning Lights, Erratic or Malfunctioning Vehicle Systems, Reduced Vehicle Performance
Possible Causes of U0017 Code :
- Wiring or Connector Issues: Loose, corroded, or damaged wiring/connectors related to the CAN bus network.
- Faulty CAN Bus Module: A malfunction or failure in the CAN bus control module or its components can cause communication errors.
- Faulty Grounding: Inadequate grounding in the vehicle’s communication system may result in a high signal.
- Short Circuit: A short circuit on the bus line, potentially from faulty insulation or wiring, could cause improper communication and high voltage signals.
- Software Glitch or Corruption: Occasionally, software errors within the vehicle’s modules can cause CAN bus communication issues.
- Faulty Sensors or ECU: A malfunctioning Electronic Control Unit (ECU) or sensor that communicates over the Medium-Speed CAN may trigger this error.
How to Fix It?
Be sure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.
Common Diagnoses and Repairs:
- Scan for Codes: Use an OBD-II scanner to verify the U0017 code and check for related codes that might point to other faults.
- Inspect Wiring and Connections: Examine the CAN bus wiring, connectors, and the affected modules to check for physical damage or loose connections.
- Test Grounding: Ensure that all grounding points for the CAN system are intact and secure.
- Check the CAN Bus Module: Test the medium-speed CAN bus module for proper operation and replace it if necessary.
- Check for Shorts: Use a multimeter to check for any short circuits along the bus line or in the associated components.
- Perform a System Reset: If software corruption is suspected, perform a reset or reprogram the affected module to clear any glitches.
