Tips on How to Use an OBD2 Scanner to Diagnose Car Issues
If the check engine light is on, a car tester or an OBD2 scan tool is necessary for diagnosing the problem. No matter your level of expertise, a scan tool is needed to communicate with the on-board diagnostic system (OBD II) and diagnose problems on your vehicle.
What Are the Different Types of Scan Tools?
A car tester or code scanner and code readers can range from devices that can read and clear codes to advanced scanners that can do much more and help with diagnosing and testing, like communicating with modules and commanding different functions. There are also Bluetooth adaptors that can connect to your phone.
Do Bluetooth Car Code Scanners Work?
A Bluetooth car tester can give a lot of information to work with, but can also be difficult to connect to.
Can an Amateur Use an OBD II Scan Tool?
The advanced scan tools are better if you do a lot of automotive repairs, but the basic scan tools work fine if you do repairs once in a while.
How to Determine Which Fault Code Caused the Check Engine Light
Scan tools that have connectors will all have an OBD II connector or DLC connector. This connector connects to a similar-looking port usually found underneath the steering wheel or dash on the driver side. Sometimes the port is covered by a small door panel.
Connect the scanner to the port. Turn the key to the ON position. Follow the directions on the scan tool to get the code to diagnose the check engine light.
What Will I See on the Car Tester?
Depending on the type, the scanner will have a series of steps to read any codes stored in the computer. All scan tools work the same. The more advanced scan tools require inputting more information, such as the make, model, and VIN number.
What Do the Different Kinds of Codes Mean, Such as Pending and History?
A pending code means the computer is still running tests.
A current code means the computer has detected a problem with the vehicle.
A history code means there may be no problems with the vehicle, but that something may have triggered the check engine light in the past that is not a current issue.
Will a Car Tester or OBD II Scanner Fix My Car or Tell Me Which Part to Replace?
An OBD II scanner can clear codes and remove a check engine light, but the engine light will return if no parts were diagnosed or repaired.
The code will tell you why the check engine light is on. It won’t tell you which specific part is causing problems but can direct you to where the issue is to help with diagnosing.
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