What are DTC codes and where do I find them?

DTC (Diagnostic Trouble Codes) are standardized error codes generated by the control unit when a problem is detected.

Format: B1234 or B1234:5 (with sub-code).

You can find DTC codes using:

• An OBD diagnostic tool — connected to the vehicle's OBD port.
• Professional diagnostic software — VCDS, Launch, Autel, etc.

When filing a dispute, include all DTC codes reported by the module after the reset.