Any modern vehicle is now equipped with some kind of on-board computer diagnostic system (OBDII). What this computer does is watch and monitor major systems operating in your vehicle. If a system starts doing something strange or malfunctions, the OBDII will turn on a service engine or check engine light that lets you know something is going on.
When it comes to engine diagnostics, what matters is that when you see a dashboard light that alerts you that something is amiss, you visit an auto service shop as soon as you can. However, it is also suggested that you have your engine checked about once a year, even if you haven’t noticed any check engine lights. This will ensure everything is still working okay.
There are many things that can go wrong with a vehicle engine and in many cases, these things are hard to pinpoint even for a professional if they aren’t using a diagnostic tool. As such, if you have a check engine light on, the diagnostic services give insight into what is going wrong. There are many reasons that a check engine light might come on, including the following:
In most cases, what will happen is a technician will do a scan of your vehicle’s computer using specialized equipment. This will bring back diagnostic trouble codes, along with descriptions of those codes. At that point, the technician can check a database that mentions any diagnostic trouble codes that have been issued by the manufacturer. This will let them understand what is causing the light and how to fix it.
Beyond that, there are other options. The technician may do a road test to determine that the complaint you have is currently occurring. They will also check the engine compartment visually to see if any obvious problems are unearthed. They may do an analysis of the charging and battery system. Other tests may be required such as spark plugs, compression, fuel pressure, or testing of other components.
Once this is complete, you will learn what is malfunctioning and what your options are. The technician will give you an estimate for the repair and you can decide what to do from there. If you want to have the repair done, that may need to be scheduled or it may be something that can done on the same day.