A Complete Guide To On-Board Diagnostic Trouble Codes (DTC) Meanings

A Diagnostic Trouble Code (DTC) is a code generated by the onboard diagnostics system in a vehicle. It is designed to indicate a specific issue or malfunction within the vehicle’s components or systems. DTCs help technicians and mechanics identify and diagnose problems by providing a numeric code that corresponds to a particular fault.

When a vehicle’s onboard computer detects an irregularity or malfunction, it triggers a corresponding DTC. These codes can cover a wide range of issues, from engine and transmission problems to issues with the emission control system or other electronic components.

Professional diagnostic tools can retrieve these codes, allowing technicians to interpret them and determine the necessary repairs or maintenance tasks to address the identified problems. DTCs play a crucial role in modern vehicle diagnostics, aiding in efficient and accurate troubleshooting during car repairs.

How do you read an OBD-II DTC?

OBD II Diagnostic Trouble Codes consists of a five-digit alphanumeric code. The first character, a letter, identifies which control system sets the code. The other four characters, all numbers, provide additional information on where the DTC originated and the operating conditions that caused it to set. Here below is an example to illustrate the structure of the digits:

How do you read an OBD-II DTC

Location of the Data Link Connector (DLC)

The DLC (Data Link Connector or Diagnostic Link Connector) is the standardized 16-cavity connector where diagnostic scan tools interface with the vehicle’s on-board computer. The DLC is usually located 12 inches from the center of the instrument panel (dash), under or around the driver’s side for most vehicles. If Data Link Connector is not located under dashboard, a label should be there telling location. For some Asian and European vehicles, the DLC is located behind the ashtray and the ashtray must be removed to access the connector. If the DLC cannot be found, refer to the vehicle’s service manual for the location.


ODB2 Diagnostic Trouble Codes Lists (DTCs):

A profound comprehension of Diagnostic Trouble Codes (DTCs) is imperative for individuals engaged in automotive maintenance and repair. Utilizing this extensive compilation, you can promptly discern potential issues within your vehicle’s systems and enact suitable measures. Whether you’re grappling with engine malfunctions, transmission glitches, or electrical anomalies, having this reference at your disposal will streamline the troubleshooting endeavor and guarantee your vehicle’s sustained peak performance. Stay abreast of developments, adopt a proactive stance, and uphold your vehicle’s seamless operation through the invaluable assistance of Diagnostic Trouble Codes.