Vehicle Trouble Codes and Diagnostics

The U0016 OBD-II code indicates a fault in the Medium Speed CAN Communication Bus (-) within the vehicle’s diagnostic system. This issue has been detected by the vehicle’s ECU (Electronic Control Unit), which has identified a problem with the Medium Speed Controller Area Network (CAN) communication bus (-). This bus is responsible for facilitating signal transmission between various control modules in the vehicle.

The Medium Speed CAN Bus operates at a speed of approximately 125 kbit/s and is typically used for systems that do not require the high-speed data transfer capabilities of the High-Speed CAN bus, which operates at 500 kbit/s or higher.

Symptoms:

Communication Failure, Check Engine Light (CEL), Loss of Functionality, Diagnostic Tool Errors

Possible Causes of U0016 Code :

• Faulty Wiring or Connections: Damaged or corroded wires, loose connections, or bad connectors in the Medium Speed CAN bus can cause communication failure.
• Defective Control Module: A malfunctioning ECU or other control modules on the CAN bus can cause the communication issue.
• CAN Bus Short Circuit: A short circuit within the wiring could prevent signals from traveling correctly.
• Faulty Termination Resistor: CAN systems require resistors at both ends of the bus for proper termination. A faulty or missing resistor can disrupt communication.
• Interference or Grounding Issues: Electrical interference or poor grounding can corrupt the signal transmission on the bus.

How to Fix it?

Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Common Diagnose and Repairs:

• Inspect Wiring and Connectors: Look for visible signs of damage, corrosion, or loose connections in the CAN bus network. Repair or replace damaged parts.
• Check the Control Modules: Ensure that the control modules communicating over the CAN bus are functioning correctly. A scan tool might be able to identify which module is failing.
• Check Termination Resistors: Verify that the resistors at the ends of the bus are correctly installed and functional.
• Check for Interference: Investigate electrical issues or grounding problems that might affect the CAN bus communication.
• Clear the Code: After addressing the problem, use a scan tool to clear the code and see if it returns.