Vehicle Trouble Codes and Diagnostics

The U0014 OBD-II code signifies an issue with the Medium-Speed CAN Communication Bus (+). This code specifically points to an abnormal high voltage or out-of-range voltage on the positive line of the medium-speed CAN bus. The OBD-II system, which monitors communication among the vehicle's various modules and components, detects this issue.

This code involves the Medium-Speed CAN bus, which is typically used for modules such as body control modules and powertrain control modules. It is triggered when the voltage on the Medium-Speed CAN (+) line deviates from the expected range, leading to disrupted or improper communication between the connected control modules.

Symptoms:

Warning Lights on the Dashboard, Malfunctioning of Vehicle Functions, Loss of Communication with Control Modules, Unusual Vehicle Behavior

Possible Causes of U0015 Code :

• Wiring Issues: A damaged or disconnected wire on the medium-speed CAN bus can cause the circuit to open, disrupting communication.
• Faulty Control Module: A failing or defective ECU or control module that is connected to the bus might cause the bus to lose communication.
• Loose or Corroded Connectors: Poor connections due to corroded or loose terminals can interfere with the communication signals on the bus.
• Electrical Short or Interference: An electrical short or interference in the wiring can lead to communication failures, including an open circuit.
• Faulty Resistor or Termination: The bus network uses termination resistors to ensure proper signal integrity. If these are missing or faulty, it may lead to communication issues.

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:

• Visual Inspection: Inspect the wiring and connectors of the medium-speed CAN bus for damage, corrosion, or loose connections.
• Use a Scan Tool: A professional OBD-II scan tool can be used to check the specific control modules for communication issues and to identify the source of the fault.
• Test the CAN Bus: Technicians may use a CAN bus tester to verify the integrity of the network, ensuring that all modules are correctly connected and communicating.
• Check for Faulty Modules: Isolating and testing individual control modules may help determine if one is malfunctioning and causing the bus to go offline.