A few decades ago, you can see the entire engine's mechanical devices under the hood. There was no obd scan tool. You know that a car needs a repair only when you see something wrong, or hear something unusual. Today's cars are like computers. There are lots of electrical sensors and modules involved. The basis of the engines hasn't changed, but they are by these electrical devices. When something went wrong, the computer notices it from the information collected through the sensors. In many cases, you don't feel much difference in the performance of the engine because the computer detects the engine's faults in their early stage.

Although the computer has lots of information of the engine and controls it, when detecting the fault, all it does for you is illuminate small warning light on the dashboard called check engine light. If you want the computer to disclose the information, you will need an obd scan tool.

Obd stands for on-board diagnostics. All cars, sold in the U.S. in 1996 and later, have an obd port under the dash. A scan tool has a connector that plugs into the port. Then you can communicate with the computer through a scan tool. How much information you get depends on scan tools. Some scan tools can access to not only the engine computer, but also ABS and Airbag computers.

Some scan tools work with laptops and cell phones. These types of scan tools are nothing but cables or adapters that have plugs fitting to the obd port. There is a lot more to it than just engine diagnostics. You can see a load of information while you are driving. You can pick up only information you need and arrange them on the display of your laptop or cell phone, and keep the record of them for off-vehicle analysis.

The great thing about obd adapters or cables is that you can choose apps or software you like. There is much apps or software compatible with them. You can try demo versions, and you can switch to a different app or software without purchasing another adapter or cable.

Geeks develop new apps every day. It is really fun to try new apps. One android app records video with cell phone's camera and overlay route map and sensor's data while you are driving. Another android app lets obd adapters access to body control computer. Then with your cell phone, you can remotely lock and unlock your car, roll up and down windows, control the radio, etc.

As you see, there are lots of potential for obd adapters and cables. I'm looking forward to seeing new apps. If you are car enthusiasts or someone who likes to play around with apps, I believe you will enjoy them.