Vehicle Computer Diagnostics: What You Need To Know
If you have ever owned a car, it is highly likely, at one time or another you have had that pesky check engine or a brake light pop up on your dashboard. Many people will automatically start to freak out. If this happens, it means that there is a problem. Your computer system will initiate and make you aware of the problem. So, this is a good and a bad thing. At least now, you know you have a problem. The computer system in you vehicle acts like the brain, since it gives other components instructions, regulates the inputs, and recognizes when something is not right. The computer system in you vehicle is a very complex system, but there have been many diagnostic tools designed to help read the computer.
When you take your vehicle into the repair shop and the mechanic tells you that you need a computer diagnostic test run, it can sound like a scary thing, and scary things usually means lots of money, but do no be alarmed the computer diagnostic test is a very common way of troubleshooting a vehicle. If you are worried you can have the technician explain to process to you.
ECS (Electronic Control System)
In every modern made vehicle there is a device called the ECS (Electronic Control System), this system knows and monitors the operating conditions of every electrical component. When the PCM (Power Control Module) detects an abnormal reading it stores a DTC (Diagnostic Trouble Code).
Accessing The DTC
When a mechanic needs to pull a stored code from the DTC, he or she will hook up a scan tool, which is the actual diagnostics-testing tool, to pull up the code. The diagnostic tool is just a small hand held device, not too different than an I-Pod, which is hooked up under the driver’s side dashboard. It is hooked up with a cable similar to a USB cable.
Reading The DTC Code
The DTC does not tell if the actual part is bad, instead it will only tell the tech where the PCM has recognized an abnormal reading. This means that something is wrong in that particular area. The issue could be with the part or it could be with the circuit leading up to that part.
False Readings
Sometimes the DTC can register an error code when there is nothing wrong with the ECS. This issue can occur when you have a vacuum leak, because a vacuum will give the PCM false readings.
Locating The Problem
In order for the technician to find the actual problem he or she will start with the DTC. Other tests might have to be performed like mechanical checks, engine compressions tests, or electronic testing.
Technical Training
Hooking up the scan tool is the easy part of this process, but in order for the mechanic to be able to pin point the problem, it takes extensive training, because he or she needs to know what circuits need to be tested and how to test them. This is not something that a home mechanic could or should undertake.
In doubt you should always get experienced mechanics to help you, like those here.
