On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. In the United States, this capability is a requirement to comply with federal emissions standards to …

A summary of pass/fail standards for the On-Board Diagnostic (OBD) test portion of a Smog Check inspection and instructions for inspecting vehicles with known OBD test difficulties.

Modern on-board diagnostic systems take a lot of the guesswork out of figuring out what's wrong with your vehicle. Learn how OBD works.

On-Board Diagnostics (OBD) is the built-in system in modern vehicles that monitors engine health, emissions performance, and overall drivability. If you’re trying to understand a Check Engine Light or …

OBD systems monitor emissions to ensure that vehicles meet minimum requirements at all times. They also alert users when emissions exceed acceptable limits so that the issue can be addressed and …

May 19, 2025 · Curious what OBD stands for in cars? Learn what On-Board Diagnostics means, how it works, and why it’s essential for vehicle maintenance.

In response to this, modern alternatives have been developed including WWH-OBD (World Wide Harmonized OBD) and OBDonUDS (OBD on UDS). Both seek to streamline and enhance OBD …

Jul 19, 2025 · OBD stands for On-Board Diagnostics, a built-in computer system in vehicles that monitors engine performance, emissions, and other critical systems. It logs Diagnostic Trouble …

OBD stands for “ O n- B oard D iagnostics.” It is a computer-based system originally designed to reduce emissions by monitoring the performance of major engine components.

Do you know what those fault codes displayed on your vehicle’s on-board diagnostics system mean? Check out our guide to OBD-II codes.