A diagnostic test is a specialised software which accurately point to problem areas in a car’s engine or elsewhere. It can detect problems long before they cause a breakdown. Diagnostic tools can also check a car’s computer system for manufacturer notifications and stored information about the car’s history, giving technicians a complete picture in order to perform the best repair possible.
Diagnostic tests can reveal problems within a vehicle’s; engine, transmission, exhaust system, brakes, and other major components, as well as performance issues with the fuel injector, air flow and coolant, ignition coils, and throttle.
However, a common misconception about car diagnostic tests is that mechanics can use code-reading tools to determine the exact problem that triggered the check engine light. In reality, the code tells mechanics which engine or component parameters are out of range, but it does not detail the cause of the problems. That’s where the good old human brain comes in handy, as the technician uses experience and expertise to diagnose the underlying problem.