What is a diagnostic test on a car?

A diagnostic test on a car is typically performed using an onboard diagnostic (OBD) system or a scan tool to determine the root cause of any issues the vehicle may be experiencing. This test can identify problems with the engine, transmission, exhaust system, brakes, and other major components of the vehicle.

During a diagnostic test, the scan tool is plugged into the OBD port of the car, which is usually located under the dashboard. The tool then communicates with the car's computer system to retrieve error codes and data related to the performance of various components.

The diagnostic test can reveal a range of issues, including engine misfires, faulty sensors, malfunctioning catalytic converters, and more. This information helps mechanics pinpoint the exact problem and plan repairs accordingly.

Overall, a diagnostic test on a car is an essential step in car maintenance and can save time and money by identifying potential problems early on. It is recommended to perform regular diagnostic tests to ensure the overall health and performance of the vehicle.