Performing an engine diagnostic starts with plugging a device into the
car's onboard computer. There is usually a space to do this just under
the dashboard on the driver's side of the car. The device interfaces
with the computer, returning a diagnostic code which can be referenced
against a list of codes for vehicles from that manufacturer. If the
engine is in good working condition, the device wi...ll inform the user. If there is a problem, one or several codes may be displayed.
Codes can mean a wide variety of things. During an engine diagnostic,
the mechanic determines what is causing each code to display, for the
purpose of developing an estimate to let a driver know how much it will
cost to address a problem. Sometimes, the issue is simple, while in
other cases, it can be very complex.
